# Really cheap true cc/cv usb charging board



## litos (Mar 26, 2012)

Hello everybody!


I'm a new member in this community. I always liked flashlights but i was unaware that there were people addicted to them. 


I have a cheap 3xAAA flashlight that i modded with an R2 drop in. I use it all the time in my work (i'm a mechanical engineer and i work in a brick producing plant). The main feature is an adjustable magnetic base that allows me to attach it to any machine and point it anywhere.


At this point i want to upgrade to something more bright, more reliable and with longer runtime, but i want to do it on a tight budget.


I'm thinking of buying the ultrafire 501-B flashlight with the XM-L T6. I can get it for 14 USD in ebay.


What made me open this thread was the charger. After googling a while, i'm convinced that i can have a very good charger for a very low price. I don't need a fancy cradle charger, or multi bay charger, just something that i can attach to a 18650 and charge it saflely acording to the cc/cv algorithm.


I was going around the TP4054 IC, when i found this board:


Ebay Item number: 330699360128



It uses a TP4056 IC, has 1A output current, but can be adjusted to other currents by changing one resistor. It follows cc/cv algorithm. If i can charge a 18650 battery with a 1A current then this is pretty much plug and play.


This leads me to my first question. Is it safe to charge a 18650 battery, let's say a 2500mAh with 1A current? 


On the other hand, if i connect this to an USB port (maximum output of 500mA) or a wall cell phone charger (also 500mA), then, even with this resistor setting, the current going to the battery will allways be lower than 500mA, right?


Another issue is the battery temperature. On this board the monitoring of the battery temperature is disabled. I believe thats also true for the majority of the chargers out there, but still i have safety concerns. So i had an idea,and i would like to know your opinion. This chip as a built in thermal feedback, that regulates the charging current to prevent the die from overheating. I was thinking that if i place the battery on top of the chip while charging, and if by any reason it overheats then it will also heat the chip reducing the charging current. Will this work? Any of you guys have experience with this board or IC?



Previously i was thinking of modding the flashlight so that the battery could be charged inside, but i'm not so sure now. Is it safe to charge the battery in a so tight sealed enviroment?


This thread is mainly about the charger but please fell free to give me your opinion about the flashlight also.


Thank you guys!


----------



## Norm (Mar 26, 2012)

:welcome:

Interesting item, I've never notice that module before. I've ordered few to play with.

Cheers Norm


----------



## mvyrmnd (Mar 26, 2012)

litos said:


> This leads me to my first question. Is it safe to charge a 18650 battery, let's say a 2500mAh with 1A current?




Yes




> On the other hand, if i connect this to an USB port (maximum output of 500mA) or a wall cell phone charger (also 500mA), then, even with this resistor setting, the current going to the battery will allways be lower than 500mA, right?



Yes




> Another issue is the battery temperature. On this board the monitoring of the battery temperature is disabled. I believe thats also true for the majority of the chargers out there, but still i have safety concerns. So i had an idea,and i would like to know your opinion. This chip as a built in thermal feedback, that regulates the charging current to prevent the die from overheating. I was thinking that if i place the battery on top of the chip while charging, and if by any reason it overheats then it will also heat the chip reducing the charging current. Will this work? Any of you guys have experience with this board or IC?



I have no idea. I guess so. At 500mA, you'd need a really dodgy 18650 to be worrying about overheating. Buy quality cells and you won't have much to worry about.






> Previously i was thinking of modding the flashlight so that the battery could be charged inside, but i'm not so sure now. Is it safe to charge the battery in a so tight sealed enviroment?



If the battery vents while charging, your sealed environment would be more like a pipe bomb. If you don't want your light to be waterproof, you can drill a venting hole in it to allow for safe charging.


----------



## litos (Mar 26, 2012)

Norm said:


> :welcome:Ive edited your eBay link, we don't allow direct links to eBay or dealer web sites, you may mention a dealer by name. Interesting item, I've never notice that module before. I've ordered a couple to play with.Cheers Norm


Thanks norm! I read some rule about long links not being allowed, but i guess i missed that one about direct links to dealer web sites .


----------



## bstrickler (Mar 27, 2012)

Hmmm... Seems like a perfect board to use for my bluetooth headset, so I don't have to carry 2 chargers with me all the time (its charger charges at 200 mA, while my cell phone charger charges at 1A, and my external battery pack charges at 600mA). Swap the input connector with a micro USB, put a micro USB output, change the resistor, and voila, 1 less charger I have to carry.



Now if I could find a 1.5v boost charger for charging at a constant 4.5/5v (lower current output, like 20mA would be fine, considering I usually charge my headset when I'm sleeping, and would also work great for my Ipod nano), I'd be ecstatic!

I have soooo many AAA, AA, and D cell batteries that could benefit from a charger like that, considering I don't go through many batteries in my E01 (same battery for the last 6-8 months), or my E05 (still on its first battery, after about 2-3 weeks).


----------



## mvyrmnd (Mar 27, 2012)

Norm said:


> Interesting item, I've never notice that module before. I've ordered few to play with.
> 
> Cheers Norm



I just did the same 

cottonpickers uses the same IC in his USB chargers, and they work fantastically. If this is even half as good, for the money it'd be brilliant!


----------



## CKOD (Mar 27, 2012)

litos said:


> On the other hand, if i connect this to an USB port (maximum output of 500mA) or a wall cell phone charger (also 500mA), then, even with this resistor setting, the current going to the battery will allways be lower than 500mA, right?



You will have to lower the charge current to <500mA to be compatible, it wont limit current, other than to just shut off the port/trip a polyfuse.


----------



## mvyrmnd (Mar 27, 2012)

CKOD said:


> You will have to lower the charge current to <500mA to be compatible, it wont limit current, other than to just shut off the port/trip a polyfuse.



I have one of cottonpickers chargers that uses the same IC.

If I set it to 750mA, and plug it into a standard 500mA USB port, it simply charges at 500mA.


----------



## litos (Mar 27, 2012)

mvyrmnd said:


> cottonpickers uses the same IC in his USB chargers, and they work fantastically. If this is even half as good, for the money it'd be brilliant!



That's exactly what i thought. I was thinking of assembling a board like this, and then i found this one. I couldn't built it for this price myself.


----------



## Ctechlite (Mar 27, 2012)

There are USB chargers that will output 2 amps. My wife uses one for her ipad.


----------



## Norm (Apr 16, 2012)

Has anyone received any of these charger boards yet?

I have just received three, (yet to test them) I was interest in varying the current as stated in the auction, I'm unsure of the resistor to change. Three message to the seller so far no helpful reply one stating "change the resistor" but not tell me which resistor, one saying "it can't be done" which is wrong I'm sure and the final message asking if I want a refund.

I'll post progress if any, currently waiting on a fourth reply but I'm not holding my breath for a sensible response.

Norm


----------



## AmperSand (Apr 16, 2012)

Norm said:


> Has anyone received any of these charger boards yet?
> 
> I have just received three, (yet to test them) I was interest in varying the current as stated in the auction, I'm unsure of the resistor to change. Three message to the seller so far no helpful reply one stating "change the resistor" but not tell me which resistor, one saying "it can't be done" which is wrong I'm sure and the final message asking if I want a refund.
> 
> ...



I received one yesterday. I myself have had no time to play either. Just checked the datasheet for the TP4056 IC it uses and have come to the conclusion what you are looking for is in the following pic.


----------



## Norm (Apr 16, 2012)

AmperSand said:


> I received one yesterday. I myself have had no time to play either. Just checked the datasheet for the TP4056 IC it uses and have come to the conclusion what you are looking for is in the following pic.



Thanks lovecpf

Norm


----------



## AmperSand (Apr 18, 2012)

Sorry the pic looks a bit dodgy, iPhone at work wasn't exactly a great shot but gets the idea across.
If my soldering iron and other gear hadn't been stolen from my car a few months ago I'd have had mine nice and functional as a charger for my 3100mah cells I use in my Fenix PD31/Eagletac D25LC2/Eagletac G25C2. Normally use a hobby charger at home. But this is great for laptop bag/at work without having to take a hobby charger everywhere.
Thinking about getting some 18650 holders and building the USB module into it.
Portable/safe Li-ion charger!!!!


----------



## Norm (Apr 18, 2012)

AmperSand said:


> Thinking about getting some 18650 holders and building the USB module into it.
> Portable/safe Li-ion charger!!!!


I have a Pila but I think I'll put a couple of boards into an old WolfEyes Charger just for the fun of the project.

Norm


----------



## mvyrmnd (Apr 19, 2012)

I've got a 2.5A 5V supply, I'm going to use two of these to refit a dead wf-188 to have two independent 1A channels


----------



## AmperSand (Apr 20, 2012)

Just quickly rigged mine up to charge an 18650 with magnet connectors. I'm at work so I can't leave it complete at the moment but so far its gone from 4.05v (cell I have in my EDC) and its currently still in constant current stage and is upto 4.15v. Have a multimeter connected to see voltage on output to battery so I can monitor it. Its only going to my computer USB port, so its probably limited to around 500mA.
Everything seems to be going ok. I might solder the leads I have with aligator clips (which I will use magnets with) to the board and use some clear heatshrink on the board and I think that may be good enough for portability, keeps the size small.

All in all seems to be going quite well. Should be good to be able to top up my EDC's cell while sitting at my desk without having to lug around too much gear at all. Bargain for the price.


----------



## WarriorOfLight (Apr 20, 2012)

The basic problem of this board is IMO if you are using this charger board on a USB port @1A you may destroy the power lines of the used USB power port. In general most USB ports are only capable driving 500mA as maximum current. There are on some devices "high power ports" but this is not specified in USB 2.0. Depending on the design of the USB power generation of the PC it may happen the fuse of the USB power line will be destroyed or the port electronics.


----------



## spectrrr (Apr 20, 2012)

Just picked up a few of these as tinker boards, look like great fun little projects and great EDC backup chargers. 

One question I know I'll have is how to determine the value of the resister to change? I was thinking I might even solder in a second breadboard with a multi-position switch... but really I'm a "hack" when it comes to this stuff (I still like to play at tho!!!) and don't know how to determine that resister value... any help there would be fantastic!


----------



## bshanahan14rulz (Apr 20, 2012)

Ebay link says :

RPROG (k)IBAT (mA)305020701013052504300340025801.666901.57801.339001.21000


That would be a good place to start, I reckon.

Also, good find, can't wait to redo my old junked chargers


----------



## mvyrmnd (Apr 20, 2012)

WarriorOfLight said:


> The basic problem of this board is IMO if you are using this charger board on a USB port @1A you may destroy the power lines of the used USB power port. In general most USB ports are only capable driving 500mA as maximum current. There are on some devices "high power ports" but this is not specified in USB 2.0. Depending on the design of the USB power generation of the PC it may happen the fuse of the USB power line will be destroyed or the port electronics.



It's not that it will 'suck' 1A from a 500mA port... It'll just deliver 500 mA to the battery.

I doubt there'd be any risk to a USB port.


----------



## spectrrr (Apr 20, 2012)

bshanahan14rulz said:


> Ebay link says:













Thanks =)




mvyrmnd said:


> It's not that it will 'suck' 1A from a 500mA port... It'll just deliver 500 mA to the battery.
> 
> I doubt there'd be any risk to a USB port.



+1, there should likely be no risk to the port in 99.9% of the computers. 

IIRC some older designed ports (we're going back a few years here) would shut off entirely if it detected a current draw higher than it wanted to give (and 500ma was being optimistic for some of those older ports). Sometimes power cycling the computer was needed to reset the protection, sometimes just removing the load and waiting 20 secs would do it. bottom line, no damage to anything, worst case, no charge in the battery. 

Modern ports will typically just deliver the 500ma and give the charger the finger on the other half. Some will give more than 500ma 

USB 3.0 ports are spec'ed to 900ma, but will probably give it the full 1a.


----------



## AmperSand (Apr 21, 2012)

In action and charging! Just made up some alligator clip leads and soldered them to the board and encased the board in clear heatshrink.
Multimeter in line monitoring voltage for now.
Going to order a few more for use with battery cradles and maybe voltage display. Adding a switch to change charge modes as mentioned previously would also be good! Cheap and effective.


----------



## spectrrr (Apr 21, 2012)

Very nice! Can't wait for mine to arrive... might be a month from China 

I hadn't looked at the connector and just assumed that it was full size USB... mini USB makes it even smaller than had thought, now I can think of a few more chargers I could use these in......


----------



## mvyrmnd (Apr 21, 2012)

My new rig 






The boards are in parallel from a 5v 2.5A power supply, and the carrier is MDF, timber screws and lots (read: a metric buttload) of hot glue and dodgy soldering.

Either way, I now have a dual independent, 1A per channel, charger that actually fits my 32650's


----------



## mvyrmnd (Apr 21, 2012)

As a side note...

Has anyone noticed the boards getting properly hot while charging?

The input voltage is 5.05V under the 2A load - I'm guessing this is a bit higher than the voltage would be if it were being fed USB power?

It's the resistor that's getting toasty, it may just be shedding more due to the higher input voltage...

EDIT: The answer is yes. Under a 1A load, my 2A iPad USB charger measured 4.75V.

Also, conveniently, due to the way the input is wired, I can plug into one of the USB inputs and still charge both batteries  In a pinch it'd be slow, but it's still work.


----------



## mvyrmnd (Apr 21, 2012)

Follow up: the charger cooled down significantly as the cells voltage increased. I started the charge with the cells at 3.7V, so the charger was having to work harder to bring the input voltage down to the required charge voltage. Once the cells were at 4.0 - 4.1V the resistor was barely warm to the touch.


----------



## spectrrr (Apr 21, 2012)

_Nice looking little rig there mvyrmnd 
I've got a cheap Chinese universal charger which is just begging to be gutted and replaced with an IC I can actually trust without keeping one hand firmly gripped on the fire extinguisher. _


*Ran across a few more models on the bay of e's today:*


Item # *270958278638 *- 1a rated, same TP4056 IC, no USB port wired in, no LED wired in. Board is a slightly different size. Twice the $$  ... looks like it would be good for a DIY integration project, not so good for plug-n-play. 


Item # *160782678020 *- 1.5a rated, 5.8-6v (but recommends 6v), almost the same board design as the one mentioned above, except this time its running *TWO *TP4056 IC's (still one output) and what looks like dual 1.6k resistors. Item description however is identical to much of the info from the original board, and doesn't seem to apply correctly to the new dual IC 1.5a designed board. going by the resistor tables, 1.6k would = ~750ma on a single IC, so it stands to reason that one each would = ~1.5a .... I don't know, anyone have thoughts on this one? Double the price at $6.... but tempting to get one to play around with. 
Item # _150795982222_ from the same seller provides a much better detailed and clear picture of the board components.


Item # *120898714536 *- full size USB plug on it, board size looks to be quite about smaller.... but the picture is too small to see what kind of IC its using or any of its circuit designs... sold in pairs for $12 after shipping, so kind of an expensive experiment :/


----------



## Quest4fire (Apr 25, 2012)

Updates anyone? Lets keep this cool thread alive...


----------



## Norm (Apr 25, 2012)

I've only gotten as far as post 23 and have charged half a dozen or so batteries, so far everything looks fine.








Norm


----------



## mvyrmnd (Apr 25, 2012)

I charged those 32650's all the way up. When the lights went blue they settled to 4.18V (yay) and I left them in with the multimeter attached to see if there was any evidence of trickle charging. After another hour the voltage had dropped to 4.17V, leading me to believe there is full termination (double yay).

This will now be my full time 32650 charger


----------



## Norm (Apr 25, 2012)

Sounding good Simon, my hold up is finding my old chargers, we had new carpet installed about 4 months ago and everything was moved, I'll have to make a concerted effort to find them.

Norm


----------



## dmprok (Apr 25, 2012)

litos said:


> What made me open this thread was the charger. After googling a while, i'm convinced that i can have a very good charger for a very low price. I don't need a fancy cradle charger, or multi bay charger, just something that i can attach to a 18650 and charge it saflely acording to the cc/cv algorithm.
> 
> I was going around the TP4054 IC, when i found this board: Ebay Item number: 330699360128
> 
> It uses a TP4056 IC, has 1A output current, but can be adjusted to other currents by changing one resistor. It follows cc/cv algorithm. If i can charge a 18650 battery with a 1A current then this is pretty much plug and play.



I saw your thread originally back when you posted, but it just hit me now after about reading old thread about using a cell phone a charger to charge battery, why not use a universal cell phone charger such as ebay item: 110816989744 ? It's dirt cheap and it has already AC plug (build in PS) you just need to connect/solder wires to a battery holder or magnets, clamp, whatever to connect. We used about 10 of these chargers at my work to charge our batteries. The only downside it's only 400 mah and will take a while to charge higher capacity 18650s. BTW, I did order couple chargers you posted, I like the fact that I have plenty of wall AC adapters that output anywhere from 350mah to 2000mah, so I can control charging current without messing with with replacing resistor.


----------



## litos (Apr 27, 2012)

dmprok said:


> I saw your thread originally back when you posted, but it just hit me now after about reading old thread about using a cell phone a charger to charge battery, why not use a universal cell phone charger such as ebay item: 110816989744 ? It's dirt cheap and it has already AC plug (build in PS) you just need to connect/solder wires to a battery holder or magnets, clamp, whatever to connect. We used about 10 of these chargers at my work to charge our batteries. The only downside it's only 400 mah and will take a while to charge higher capacity 18650s. BTW, I did order couple chargers you posted, I like the fact that I have plenty of wall AC adapters that output anywhere from 350mah to 2000mah, so I can control charging current without messing with with replacing resistor.



I also looked at a couple of those chargers, and some cheap others like ebay item: 390310966680, or ebay item: 280855992241, but for me, the big problem with all of them is that i don't know what's inside. They might follow a cc/cv algorithm, but there is no way for me to know that. On the other hand, this little charging board, while being cheap uses a chip that as been tested and reviewed, and that i know performs as expected.


----------



## Aquanaut (May 11, 2012)

I just hooked up the charger from ebay, using magnets for the battery contacts and an Apple power cube for the power supply. Talk about a small charger! My li-ion cell charged up to 4.23V after resting for 1/2 hour, which is well within the 1.5% charge precision stated by the seller. The leds on the charger changed from red to blue, indicating proper charge status. Not bad for a charging board that costs $2.99 including free shipping from Hong Kong.


----------



## Norm (May 12, 2012)

I tried charging an 18650 using one of these chargers and a CottonPickers large solar cell a couple of days ago, works perfectly. One small thing worthy of note, if the charge leads are disconnected from the cell the power to the charger will need to be removed momentarily to reset the circuit before it will resume charging. 

Norm


----------



## rapid (May 12, 2012)

Aquanaut said:


> I just hooked up the charger from ebay, using magnets for the battery contacts and an Apple power cube for the power supply. Talk about a small charger! My li-ion cell charged up to 4.23V after resting for 1/2 hour, which is well within the 1.5% charge precision stated by the seller. The leds on the charger changed from red to blue, indicating proper charge status. Not bad for a charging board that costs $2.99 including free shipping from Hong Kong.


Hi Aquanaut,
your module really stop the charge when the final voltage was reached or only change the led colour?
Many thanks


----------



## Lynx_Arc (May 12, 2012)

That Ebay # is no longer available, but you can get the board from other vendors for about $4 now
Search for lithium battery charger board. There is one "listed" that says 1.5A but the stats don't match the 1.5A output so someone would have to contact the dealer to make sure it was a typo or not.. $5.69 for it.


----------



## Aquanaut (May 12, 2012)

rapid said:


> Hi Aquanaut,
> your module really stop the charge when the final voltage was reached or only change the led colour?
> Many thanks



:welcome:

There are two leds. When the red charging led turned off and the blue termination led turned on, the voltage was 4.22V. After one hour still on the charger, the voltage dropped to 4.19V. This is convincing evidence that charging has stopped.


----------



## Magic Matt (May 12, 2012)

I've only skim-read the thread, so apologies if I've missed something, but the limited USB output of 500mA is only for USB1.1 - with USB2, you can use the port as a charger by shorting the data pins (2 and 3) - this tells the system that the USB device connected is a charger, and if the hardware is capable it will output far more than 500mA quite happily, and the spec allows up to 1800mA. This is exactly what the iPad chargers etc. do. There is risk to the USB port, and I've seen them fried, by trying to pull more than the 500mA without shorting the data pins, though most smart systems just turn off the port until the system is reset, and you'll get some sort of error reported in your Operating System.


----------



## Lynx_Arc (May 12, 2012)

Magic Matt said:


> I've only skim-read the thread, so apologies if I've missed something, but the limited USB output of 500mA is only for USB1.1 - with USB2, you can use the port as a charger by shorting the data pins (2 and 3) - this tells the system that the USB device connected is a charger, and if the hardware is capable it will output far more than 500mA quite happily, and the spec allows up to 1800mA. This is exactly what the iPad chargers etc. do. There is risk to the USB port, and I've seen them fried, by trying to pull more than the 500mA without shorting the data pins, though most smart systems just turn off the port until the system is reset, and you'll get some sort of error reported in your Operating System.


I wouldn't try to draw more than 500ma from a non USB 3 port. If you wanted to charge something requiring more current I would be more tempted to hack the charger and short the pins out on it instead so you won't forget and plug in your hacked cable and fry a usb power supply that isn't smart enough to turn off when current draw is too much.


----------



## Norm (May 12, 2012)

I find it's much more convienient to use my ipad or other USB mains charger, there are plenty around the house. 

Norm


----------



## Aquanaut (May 12, 2012)

Norm said:


> I find it's much more convienient to use my ipad or other USB mains charger, there are plenty around the house.
> 
> Norm



+1

See post #35. By "Apple power cube" I meant a plug in USB power supply. My ipad power cube supplies 2A at 5V (10 watts). iPhone, iPod, etc. power cubes supply 1A.

Be careful buying power cubes. There are many cheap imitation cubes which are worthless.


----------



## BringerOfLight (May 14, 2012)

mvyrmnd said:


> Has anyone noticed the boards getting properly hot while charging?
> ...
> Follow up: the charger cooled down significantly as the cells voltage increased. I started the charge with the cells at 3.7V, so the charger was having to work harder to bring the input voltage down to the required charge voltage. Once the cells were at 4.0 - 4.1V the resistor was barely warm to the touch.


That charger chip works like a linear regulator, meaning it (along with the resister that gets hot) has to burn the difference between your input voltage and output (battery) voltage. I.e. when your battery is at 3.5V, it has to burn (5V-3.5V) * 1A = 1.5W - which is quite a lot for such a tiny board without heatsinks.

I wouldn't be surprised, if the chip went into thermal protection and decreased the charge current - you might want to check that, if you care about charge time.

\\

There are a lot of boards based on similar charger chips (some with much better specs, i.e. 0.5% voltage accuracy), a collection of them is here:
http://dangerousprototypes.com/2011/11/02/partlist-wednesday-lithium-polymer-battery-charger-chips/


----------



## mvyrmnd (May 27, 2012)

Here's a question for the charger buffs - if I were to wire the outputs of two board in parallel, would I get a 2A charger, or a big explosion?


----------



## Shadowww (May 27, 2012)

mvyrmnd said:


> Here's a question for the charger buffs - if I were to wire the outputs of two board in parallel, would I get a 2A charger, or a big explosion?


No idea about that one, but there are boards with two of these chips that have claimed output of 1.5A.


----------



## czAtlantis (May 27, 2012)

mvyrmnd said:


> Here's a question for the charger buffs - if I were to wire the outputs of two board in parallel, would I get a 2A charger, or a big explosion?


You would get 2A charger. But there might be problem with enough current from your PC's USB port.


----------



## mvyrmnd (May 27, 2012)

It's a good thing I'm using a 5V PSU, or an iPad 10W charger instead of my USB port


----------



## czAtlantis (May 27, 2012)

It is fine then. Anyway even from standard PC's USB port it is possible (in most cases) to draw 2A but it has quite high internal resistance - so it won't have 5V but 4.5V which would cause slower charge when reaching CV mode with this charger boad.


----------



## nofearek9 (Jun 3, 2012)

has anyone done the resistor mod to be able changing the current output?


----------



## Quest4fire (Jun 18, 2012)

In case anyone is interested the charging boards that the OP started the thread over are on sale for $1.99 each. The sale ends in one day according to the listing (Search item # 261043881158). The seller is e-worldseller. There is another seller that has them for the same price, but they have a low feedback count. Couldn't resist getting a few more.


----------



## russde (Jun 18, 2012)

Thanks for the heads up Quest.
Can someone point me towards a source for magnets to use to attach to the + and - of my batteries?
Cheers!


----------



## czAtlantis (Jun 18, 2012)

Thanks Quest4fire, it is very good deal! I will buy some


----------



## Aquanaut (Jun 18, 2012)

russde said:


> Thanks for the heads up Quest.
> Can someone point me towards a source for magnets to use to attach to the + and - of my batteries?
> Cheers!



I have the following and they are quite strong and nickel plated, so it is easy to solder wires onto them.

Try indigo dot com, part number *44201-7.5.
*


----------



## A987K (Jun 19, 2012)

_Yeah, it seems fun, I will try to get some soon. LIke it_


----------



## jk037 (Jun 19, 2012)

Quest4fire said:


> In case anyone is interested the charging boards that the OP started the thread over are on sale for $1.99 each. The sale ends in one day according to the listing (Search item # 261043881158). The seller is e-worldseller. There is another seller that has them for the same price, but they have a low feedback count. Couldn't resist getting a few more.



Fabulous, great find! 

I'm ordering 5 from "e-worldseller". They come out to £1.27 each including P&P to the UK, so to buy five is still vastly cheaper than buying the components to build just one charger from scratch. And I get to avoid an evening or two hunched over a soldering iron too - bonus!

*For the chap who was asking about magnets:* I know it's almost a dirty word to some people, but DX sell various sizes of circular rare-earth magnets for a few dollars per pack of 10 or 20.

_ETA: Sort of amusing how fleabay describe the price on this listing as "$1.99, approximately £1.27", yet when you get to the Paypal checkout page that has sneakily crept up to £1.306. Nice to see that the Paypal/Ebay machine isn't above outright lying and deception to make a few extra pence here and there!_


----------



## RoGuE_StreaK (Jun 21, 2012)

If we assume a USB port does limit current to 500mA (as a "lowest common denominator" approach), would sourcing power from two ports be an option? ie. one of those Y cables like some of the cheapie 2.5" HDD adapters use?


----------



## czAtlantis (Jun 21, 2012)

Yes, why not? 

Btw- anyone tried how much "true CC CV" it is? I mean if the battery is at 4.1V if it is still charging at 1A or the current is dropping. Or do I have to do it myself? :-D


----------



## Norm (Jun 21, 2012)

I really wouldn't bother with your computer USB, buy a cheap mains adapter.

Norm


----------



## RoGuE_StreaK (Jun 21, 2012)

I'm contemplating using these, or a diy version, as a built-in charger for a small-production product I'm prototyping (have to remove battery holder from product to access charger, to avoid pipe-bomb effect), so wanted to make it as versatile as possible for end-users. Good to know that if you leave it set to 1Amp it should still work on a lowly USB port, just much slower, was a point I wasn' sure of from TI's documents. I too saw these things after investigating the various offerings from Texas Instruments, would be neater to integrate TI chips directly into my own boards, but for now a separate board should suffice.


----------



## Lolaralph (Jun 23, 2012)

Would someone be willing to explain how to hook up a digital voltage display, and any info on where to source the display, I just ordered a couple of the chargers from eBay, and would like to know how to proceed. Thanks


----------



## Quest4fire (Jun 23, 2012)

Interesting idea. I seem to remember a thread where someone put a voltage display on their POB spotlight. Yep here it is. Might be helpful.


----------



## ToddC (Jul 3, 2012)

Just want to share that I bought a few from e-worldseller and assembled one of them to use as my first Li-Ion charger. I replaced the programming resistor with a SMT 0603 3.3k and used small alligator clips and magnets to charge a AW 14500 protected. I used two cheap multimeters with crappy probes to monitor both current and voltage. I measured 310mA during the CC phase (Rprog=3.3k => 363mA based on equation in the datasheet), and that steadily decreased during the CV stage (@ 4.20V). I had to leave so unplugged it before the charge cycle completed, but so far so good! The only issue I noted is the LEDs are swapped vs the ebay listing. The charging position is blue and the completed is red.


----------



## Quest4fire (Jul 3, 2012)

> Just want to share that I bought a few from e-worldseller and assembled one of them to use as my first Li-Ion charger. I replaced the programming resistor with a SMT 0603 3.3k and used small alligator clips and magnets to charge a AW 14500 protected. I used two cheap multimeters with crappy probes to monitor both current and voltage. I measured 310mA during the CC phase (Rprog=3.3k => 363mA based on equation in the datasheet), and that steadily decreased during the CV stage (@ 1.20V). I had to leave so unplugged it before the charge cycle completed, but so far so good! The only issue I noted is the LEDs are swapped vs the ebay listing. The charging position is blue and the completed is red.



Thanks for posting. If you don't mind my asking, where did you get your SMT? I just got my latest batch in the mail on Monday and am thinking about tweaking a couple.


----------



## RoGuE_StreaK (Jul 4, 2012)

Quest4fire said:


> Thanks for posting. If you don't mind my asking, where did you get your SMT? I just got my latest batch in the mail on Monday and am thinking about tweaking a couple.


I don't know about everyone else, but just buy most of my passive (and some active) SMD components on ebay, can't go past $1-2 for 100x including shipping. Or about $15 shipped for an entire reel of 5000x if you are that way inclined.


----------



## march.brown (Jul 5, 2012)

I have a small "Sony-Ericsson Charger EP800" (bought on Ebay) which is fitted with a 13A plug , so is great for charging in the UK ... It has a full-size USB socket built in , and the output is 5.0V at 850mA ... I use this to charge my small DAB radio , phones and other items ... I can't vouch for how "smooth" the DC output is though.Would this be suitable as a supply to these charging chips ? ... I also have a couple of other un-named but similar USB 5V chargers and these seem to work OK too on phones etc..


----------



## mvyrmnd (Jul 5, 2012)

march.brown said:


> I have a small "Sony-Ericsson Charger EP800" (bought on Ebay) which is fitted with a 13A plug , so is great for charging in the UK ... It has a full-size USB socket built in , and the output is 5.0V at 850mA ... I use this to charge my small DAB radio , phones and other items ... I can't vouch for how "smooth" the DC output is though.Would this be suitable as a supply to these charging chips ? ... I also have a couple of other un-named but similar USB 5V chargers and these seem to work OK too on phones etc..



It'd be fine. I've tried all sorts of 5V Inputs and it seems to eat them all up with no trouble.


----------



## march.brown (Jul 5, 2012)

march.brown said:


> I have a small "Sony-Ericsson Charger EP800" (bought on Ebay) which is fitted with a 13A plug , so is great for charging in the UK ... It has a full-size USB socket built in , and the output is 5.0V at 850mA ... I use this to charge my small DAB radio , phones and other items ... I can't vouch for how "smooth" the DC output is though.Would this be suitable as a supply to these charging chips ? ... I also have a couple of other un-named but similar USB 5V chargers and these seem to work OK too on phones etc..


Just checked the other 5V supplies and one is 500mA and the other is 1A.

Without changing the surface mount resistor (R122 ?) , what would be the charging current to a 18650 ? ... Also what would be the ideal charging current for a 2400mAh Li-Ion ? ... I am trying to avoid changing the resistor , but if I do would it be better to go for a higher wattage one ?

Unfortunately , I threw out a faulty Li-Ion charger last year ... 
I normally hoard all sorts of bits , but in a moment of weakness I had a tidy up of useless items ...





.


----------



## mvyrmnd (Jul 5, 2012)

Changing the resistor locks you into a lower charge current permanently. If you have 500, 850 and 1000mA USB chargers, then you can use them to limit the charge current instead.


----------



## Norm (Jul 5, 2012)

The one Amp charger will be fine to use in combination with one of the circuits discussed here.

Norm


----------



## march.brown (Jul 5, 2012)

Well , I have just sent for four "charger boards" and two "Battery holders for two 18650's".

My idea is to use one half of the battery holder to hold one 18650 cell and mount the charger board (25mm X 19mm) in the other half ... The unit will be self-contained and all I need to do is to plug in one of my mains/USB power supplies ... 500mA , 850mA or 1000mA as needed ... If I need to change the resistor , then I will put a higher wattage resistor in its place.

I will put a copper "loop" on each side of the battery so I can check the voltage easily by clipping on my DVM ... I sent for four charger boards and will pick the best two to be permanently mounted ... I did consider mounting a tiny fan on the unit for cooling purposes , but on reflection it might be better to put a higher wattage resistor in ... I still don't know what the optimum charging current is in the CC part of the charge , but one amp for a 2400mAh 18650 doesn't seem too bad to me.

Just a matter of waiting for the bits to arrive from the far east now ... These chargers might make my other two redundant if they are genuinly CC/CV ... Looking forward to having a play ... 

Must get some more Araldite to hold the charger board into the battery holder.
.


----------



## Norm (Jul 5, 2012)

I've dug out my old Wolfeyes Chargers but am having serious problems opening the cases, the seem to be well glued shut with no visible screws (none under the label). I might have to resort to using the dremel.

I need to order more boards to, I've given some away, may buy the style with provision for off board indicator LEDs to make mounting easier.

Norm


----------



## ToddC (Jul 5, 2012)

*Quest4fire* : As *RoGuE_Streak* suggested, ebay is one option. You can also call digikey and see what they are willing to do for you. I *think* you can get 50 of them for 45 cents or so. Under 50 the unit price is 10x so it just doesn't make sense. Look for the "Cut Tape" option on their website instead of a tape reel. Search for "SMD thick film resistor" or "chip resistor thick film" and package size 0603. You may also be able to find "sample kits" that include various resistances. You'll want to solder under a magnifying glass.


----------



## Quest4fire (Jul 5, 2012)

> I don't know about everyone else, but just buy most of my passive (and some active) SMD components on ebay, can't go past $1-2 for 100x including shipping. Or about $15 shipped for an entire reel of 5000x if you are that way inclined.





> *Quest4fire* : As *RoGuE_Streak* suggested, ebay is one option. You can also call digikey and see what they are willing to do for you. I *think* you can get 50 of them for 45 cents or so. Under 50 the unit price is 10x so it just doesn't make sense. Look for the "Cut Tape" option on their website instead of a tape reel. Search for "SMD thick film resistor" or "chip resistor thick film" and package size 0603. You may also be able to find "sample kits" that include various resistances. You'll want to solder under a magnifying glass.



Thanks for the info guys.


----------



## RoGuE_StreaK (Jul 6, 2012)

ToddC said:


> I *think* you can get 50 of them for 45 cents or so.


Yep I just checked digikey and found 50x for 46 cents; you guys ar lucky though, for me to buy them it costs $30 in shipping!!! Hence why I have to rely on ebay for a lot of things.


----------



## march.brown (Jul 7, 2012)

I am considering getting a battery holder for four 18650 cells and using two of the charging boards to make a two slot charger ... A USB mains power supply of about 2 amps would be great ... I will see how the two-cell battery holder works out first though ... Don't know how long the delivery time will be (to the UK) as the seller thinks that the Olympics will slow things down ... 
.


----------



## Aquanaut (Jul 8, 2012)

march.brown said:


> A USB mains power supply of about 2 amps would be great.



My Apple iPad USB power cube outputs 10W (2A @ 5V), model A1357. It now costs ~$16 on Amazon. Be careful, there are many imitations not up to specs. Look for the model number.


----------



## RoGuE_StreaK (Jul 8, 2012)

Magic Matt said:


> the limited USB output of 500mA is only for USB1.1 - with USB2, you can use the port as a charger by shorting the data pins (2 and 3) - this tells the system that the USB device connected is a charger, and if the hardware is capable it will output far more than 500mA quite happily, and the spec allows up to 1800mA. This is exactly what the iPad chargers etc. do. There is risk to the USB port, and I've seen them fried, by trying to pull more than the 500mA without shorting the data pins, though most smart systems just turn off the port until the system is reset, and you'll get some sort of error reported in your Operating System.


I'm waiting for my board to arrive, so haven't analysed the traces yet, but does it make sense to form a solder bridge between pins 2 and 3 if it doesn't exist, to permanently notify compliant USB ports that it is indeed a charger and to remove the limiter?


----------



## emergencyled (Jul 9, 2012)

Hi new member i have ordered this board and I have purchased 3.7v 14500 900mah icr unprotected batteries. I would like to know for the above battery, do i need to connect usb 5 volt and 500ma charger (charger at 400ma is harder to find) or do i need to change resistor. The reason i ask this is becuase it says on the eBay seller site: "It is better that the charging current is 37% of the battery capacity. If you charge to the battery of 1000mAH, current of 400 is enough." now the other part of the question the battery is unprotected but i was thinking of purchasing a PCB protection off eBay but i do not find any for 14500 but most for other lithium batteries. The trick for PCB protection was that i would connect the cc/cv board to the PCB protection and then join wires from PCB protection to the unprotected battery this way i would be using one protection pcb for all my unprotected batteries.


----------



## NoixPecan (Jul 9, 2012)

@emergencyled. It depends of what 500mA USB power source you plan to use with your 1000mA charging board. When overloaded in such a way, some USB power sources (hopefully most of them) would limit the output current to what they can safely deliver, but some of them would just overheat and fry. If changing the resistor (on the charging board) is an easy task for you, then it is the best way. Otherwise, you can try with a 500mA USB power source, but be careful the first time. Now for your second question. Such an IC-managed charging board is safe for the battery, so there would be little point in connecting an additional protection circuit module during the charge process. The aim of a protection circuit module is to protect the battery from harsh usage, like inside a flashlight.


----------



## 400THz (Jul 13, 2012)

This is a great, great thread!

I have ordered a few of these boards for 1.99$ each and I'm eager to try them. They are available from multiple eBay sellers, which is a good thing (just search eBay for "TP4056").

I've also ordered a couple of (even tinier) digital voltmeter boards (DC) that need no external power supply. They have only two terminals and are supposed to be especially good for measuring cell voltages. Sellers advertise a 3.3V–17V range and the cost is between 3.25$ and 4.40$. You can even choose the color of the 3-digit display (red, green, blue, yellow)! *A minor warning:* I already have one of these and, while quite accurate within range, when measuring a 3.1V brand-new primary lithium cell it was showing a voltage of 3,45V! So, *they can indicate an overcharged but NOT an over-discharged cell*.

Two questions:

Since these voltmeters are supposed to have an input impedance of 100kΩ (not ideal, but still orders of magnitude larger than the cell internal resistance) and are supposed to consume less than 20 mA, I'm thinking of permanently hooking one of them to the charging terminals. The purpose is having a crude "progress indicator" and, more importantly, an overcharging warning. (I do realise that the "resting voltage", as well as the "voltage under load", will be slightly different.) Will this affect the charging process? Is it safe? I believe it is, but I'd like an educated confirmation.
Does TP4056 use pulses or any kind of modulation? Or is it a "true" CC/CV charging chip? (I don't have an oscilloscope to see for myself!)
If it does (and measures the cell between pulses), I would imagine that its measurements might be slightly affected by the voltmeter due to transient effects.
According to the eBay description of the TP4056 board, one should not connect an amperemeter in series with its output. But I think that a voltmeter would be much less intrusive. I would guess that an amperemeter might interfere more with the CV phase (and thus termination) and a voltmeter more with the CC phase (which is not such a problem). But my knowledge of electronics is *very* limited.


PS. I lost everything because of a mouse accident and had to write this whole post twice. Then I discovered (but didn't try) the "restore auto-saved content" button


----------



## czAtlantis (Jul 13, 2012)

"Will this affect the charging process? Is it safe?" 
- yes it will slightly affect the last charging phase.Looking into datasheet it looks this IC terminates charge at 100mA(don't know if fixed or 1/10 of charging current), in case you connect voltmeter it will be 100-20mA (voltmeter draw)=80mA. So your batteries will be little more charged and it will took little more time but really nothing significant.

Does TP4056 use pulses or any kind of modulation?
-> I don't think so. It is linear IC so it just regulates internal resistance to match output voltage and linear stabilisators have minimal ripple.


"According to the eBay description of the TP4056 board, one should not connect an amperemeter in series with its output."
->Yes this is because every A-metter must have some resistance which means voltage drop. And charging single cell liion is very sensitive operation and even 0.05V drop means huge error. In this case the battery won't be fully charged. If you connect A-metter to the input, there will be the same voltage drop (because input and output current is the same - well minus LEDs drain and etc but it is not significant) but it is on the unregulated side - it means the IC will just have little lower input voltage and it doesn't matter (if it is within IC's input range)


----------



## RoGuE_StreaK (Jul 13, 2012)

Huh, for some reason I thought this was a Texas Instruments chip, as it corresponded with one I was looking at at the time but couldn't remember the name of. Only just realised as the chip number didn't return a result at TI.


----------



## Quest4fire (Jul 14, 2012)

> I need to order more boards to, I've given some away, may buy the style with provision for off board indicator LEDs to make mounting easier.



Hey Norm, you might have more flexibility in how you mount the boards in the charger box if you use light pipes (Clear plastic tubular optics that project the light from led on internally mounted boards to the outside surface of the box where it can be seen). They can be very inexpensive if you can find them locally or if, for instance, you were already needing something from Digikey or whoever and intended to pay shipping anyway. You might even find some you can use in electrical devices you don't use anymore.


----------



## 400THz (Jul 15, 2012)

czAtlantis said:


> "Will this affect the charging process? Is it safe?"
> - yes it will slightly affect the last charging phase.Looking into datasheet it looks this IC terminates charge at 100mA(don't know if fixed or 1/10 of charging current), in case you connect voltmeter it will be 100-20mA (voltmeter draw)=80mA. So your batteries will be little more charged and it will took little more time but really nothing significant.
> 
> Does TP4056 use pulses or any kind of modulation?
> ...


I see. Your helpful post pretty much confirms my own suspicions.



czAtlantis said:


> If you connect A-metter to the input, there will be the same voltage drop (because input and output current is the same - well minus LEDs drain and etc but it is not significant) but it is on the unregulated side - it means the IC will just have little lower input voltage and it doesn't matter (if it is within IC's input range)


Interesting, thank you.

*edit:* Of course, this analysis is a bit simplistic in that it regards the voltmeter as a purely resistive load, which it isn't. But I hope it will be close enough.


----------



## Norm (Jul 15, 2012)

Quest4fire said:


> Hey Norm, you might have more flexibility in how you mount the boards in the charger box if you use light pipes (Clear plastic tubular optics that project the light from led on internally mounted boards to the outside surface of the box where it can be seen)


I'll have to check it out 

Norm


----------



## NoixPecan (Jul 15, 2012)

spectrrr said:


> Item # *120898714536 *- full size USB plug on it, board size looks to be quite about smaller.... but the picture is too small to see what kind of IC its using or any of its circuit designs... sold in pairs for $12 after shipping, so kind of an expensive experiment :/


Indeed, that board looks really tiny:







Too bad it is 3x more expensive than the board discussed in this thread, it would have been interesting to compare.



400THz said:


> I've also ordered a couple of (even tinier) digital voltmeter boards (DC) that need no external power supply. They have only two terminals and are supposed to be especially good for measuring cell voltages.


Interesting, thank you. A few months ago, I ordered a similarly-sized voltmeter board, but with 7 terminals (to match RC hobbyists' multi-cell batteries). Such $3 lipo checkers are common on eBay, but that particuler design (search "2.8V-25.2V" with quotes) was said to be the most accurate:






For a single cell, only the first two terminals would be used. Now that I have received the $2 charging board, I plan to connect them together, like 400THz did with his voltmeter board. It should work, since it would be rather close to Cottonpickers' Smallest USB Charger. In fact, it seems (from the photos) that Cottonpickers uses the same battery checker in his design, along with the tiny USB charger board mentioned by Spectrrr (and pictured above).


----------



## RoGuE_StreaK (Jul 16, 2012)

By rotating the image and squinting, I _think_ it seems to corelate with a TP4054; package seems the same as the spec sheet I found. Very quick glance says that it's a CC/CV li-ion charger with up to 800mA charge current, that's as far as I investigated.
And there's a IN5817 miniature schottky barrier rectifier on there. Whatever that is.


----------



## NoixPecan (Jul 16, 2012)

Thank you RoGuE, you have a good sight.  So the IC is not exactly the same as in the $2 board discussed here, but very close.



mvyrmnd said:


> cottonpickers uses the same IC in his USB chargers, and they work fantastically.


Would you know if he uses a TP4056, or a TP4054 (which would confirm my assumption)?


----------



## Lolaralph (Jul 16, 2012)

400THZ and czAtlantis,
i'm interested in hooking up an inline ammeter as well, just to check the amps going to the cells i'm not exactly certain where to hook it up to cause the least amount of disturbance in the charging cycle, could you guys describe in a little more detail what you feel is the best option, czAtlantis's comment "If you connect A-metter to the input, there will be the same voltage drop (because input and output current is the same - well minus LEDs drain and etc but it is not significant) but it is on the unregulated side - it means the IC will just have little lower input voltage and it doesn't matter (if it is within IC's input range) " wasn't quite clear to me, as far as to where to actually make the connections on the board. thanks


----------



## czAtlantis (Jul 16, 2012)

Hi, I tried to draw two different ways to connect your Ammeter. The first one is like I said - every A-metter must have internal resistance (in this case 0,2ohm) According to ohm's law it means therewill be voltage drop. In our case at 1A it will be 0,2V.
When you connect it between USB and input there will be only 4,8V V on the board. But it is OK because this board is stabilizer - keeps 4,2V on output (when the input voltage is in acceptable range like 4.7-6V).

On the other hand the second schematic shows connecting A-metter between board and battery. There is the same voltage drop but in this case it is a problem. The board doesn't know there is any voltage drop and stabilises still to 4,2V. But the A-mettr adds again 0,2V drop but there is no way to compensate ->On battery is only 4,0V which will prolong charging time and you battery will not be fully charged.

PS: there is little parasitic drain of the circuit itself - In the picture I showed it as 1A input and 0,99A output but this is really not significant. Just your A-metter connected between power source and board won't show 0,00mA even with fully charged battery. I just measured it is just around 5mA


----------



## RoGuE_StreaK (Jul 16, 2012)

The issue is probably _where_ to shoe-horn in the ammeter on a board using the inbuilt USB socket; if you look at the pic posted by AmperSand on the first page (I don't have my board with me to look at) I would say to remove the "R400" resistor and connect the ammeter inline there, obviously somehow re-integrating the R400. Or you could maybe cut the thick track between the USB and R400, scrape back the soldermask, and solder the ammeter between this newly created pad and the R400 input pad.

Possibly you could "tombstone" R400, and use it's exposed end as a pad?


----------



## ToddC (Jul 16, 2012)

*Lolaralph* : What do you plan on using as the ammeter? Maybe do what* RoGuE_StreaK* suggested but install a current sense resistor and attach a volt meter across that?


BTW - The voltage drop of the current measurement that *czAtlantis* is explaining is called "burden voltage."


----------



## Lolaralph (Jul 16, 2012)

czAtlantis,
thank you very much for the time and effort of the schematics, it clears things up. I probably really don't need to use the ammeter but I want to check the changes the replacement resistors have made, and be sure I'm only sending 100 ma to my 10440's.

ToddC,

I actually purchased one of the "slimline ammeters" that e-worldseller sells, orderd it with my second batch of boards.


----------



## march.brown (Jul 17, 2012)

When the CC stage changes to the CV stage , I assume that the current drops to maybe 100mA or less (?) ... If the Ammeter is in series with the battery , then the voltage drop across the ammeter will be one tenth of when it was one amp ... According to previous calculations that would only be 0.02V drop across the ammeter ... I am assuming that the resistance of the ammeter remains constant irrespective of the ampere readings ... The battery would be charged up to within 0.02 volts of the correct terminating voltage ... So the battery voltage would be 20mV lower than the optimum 4.2V ... There will be some variation in terminating voltage of these little boards , so ideally we should be looking for a board that is terminating at 20mV over the 4.2V ... This would compensate for the inclusion of the ammeter into the output circuit.
.


----------



## bshanahan14rulz (Jul 17, 2012)

can you just measure the voltage dropped by the known resistor that is already inline with the USB power line? Then you don't have to guess or find out the resistance of your ammeter, but also then it depends on the tolerance of the particular resistor. After that, V/R=I, and 1A=1000mA.


----------



## NoixPecan (Jul 17, 2012)

mvyrmnd said:


> cottonpickers uses the same IC in his USB chargers, and they work fantastically.


Not quite. Looking for an answer to the question in my previous post, I have read Cottonpickers' first thread about his USB chargers. In fact, his first design was based on the TP4054, but after selling a few chargers, he realized that the IC poorly implements (if at all) the CC/CV algorithm (despite what is specified in the datasheet). He ended up upgrading his design, by unsoldering the TP4054 from the charger board, and replacing it by the LTC4054. This IC from Linear (which the Chinese TP4054 tries to imitate) follows the CC/CV algorithm almost perfectly.

Since the charging board we are now discussing is based on the TP4056, a question rises. Does the TP4056 follow the CC/CV algorithm any better than the TP4054? Obviously, we cannot trust the datasheet. Should one of us own a logging multimeter, it would be a good idea to check how the board actually behaves.


----------



## RoGuE_StreaK (Jul 17, 2012)

NoixPecan said:


> unsoldering the TP4054 from the charger board, and replacing it by the LTC4054. This IC from Linear (which the Chinese TP4054 tries to imitate)


Out of curiousity, and following that logic, I looked up "LTC" 4056, and yes that one also does exist (probably no surprise)
Pricing-wise, a brief search gave me about $2.20 for the LTC4054 (1-99 orders), as opposed to maybe $0.20 for the TP4054. LTC4056 is about $2.15, couldn't find reliable pricing for the TP4056, cheapest was about $0.50 each.
Just in case people want to make their own!


----------



## malow (Jul 18, 2012)

DealExtreme are selling now a 1A TP4056 based charging board. mini-usb, 2 status leds. $4.80


----------



## NoixPecan (Jul 18, 2012)

@malow. Indeed, DX sells the TP4056 board this thread is all about. It is currently much cheaper on eBay, though (only $2).


----------



## Norm (Jul 19, 2012)

Anyone familiar with TP4057, I found a site that has boards, 4.2V lithium battery charge control board lights double TP4057 lithium battery 1A

These boards uses two chips.
There is also a cheaper version using one chip for 500mA
Not sure if the current is variable.

Quantity (lot) Price (Per lot) Processing Time
1 - 3 ----------	$3.46	------------4 Days
4 - 6 ----------	$2.01-----------	4 Days
7 - 10 ---------	$1.80-----------	4 Days
11 - 15--------- $1.70-----------	4 Days



Data

Norm


----------



## malow (Jul 19, 2012)

TP4056 have 4v-8v "absolute maximum" input voltage, while TP4057 is 4.5v-15v. also, theres a 8.4v TP4057, for 2 li-ion in series charging.


----------



## bstrickler (Jul 22, 2012)

Well, I just bought 10 of these! (I need 7 for my 64656 build, running off of 7 26650's. 3 others just for spares/other stuff). Also bought 7 cables, and a powered 7-port USB hub (3 amp power supply), so I can charge the cells overnight, rather than having to charge one at a time with my hobby charger (positive node isn't magnetic, so I can't just use mangets to attach the leads). Total cost: ~$50 (not including figuring out how to make cradles)

Buying a 5k roll of 3k resistors (otherwise it becomes too much of a waste of $), in case anyone wants some. I'll hack 10 off and mail it to you for 75 cents PPG (45 cents to cover stamp, 30 to cover envelope and time).


----------



## mvyrmnd (Jul 22, 2012)

A simpler design would be to build a 7 bay cradle, run 3 of the chargers at the full 1A each with the outputs wired in parallel across all 7 bays.

You'll waste less input power, and charge just as quickly - kinda like a giant version of my dodgy 2-up charger:


----------



## bstrickler (Jul 22, 2012)

mvyrmnd said:


> A simpler design would be to build a 7 bay cradle, run 3 of the chargers at the full 1A each with the outputs wired in parallel across all 7 bays.
> 
> You'll waste less input power, and charge just as quickly - kinda like a giant version of my dodgy 2-up charger:



Only problem is the USB hub is only designed for 500ma/channel. Fortunately, I can still cancel the order.

With your idea, I'll probably just get 2 4A wall wart chargers, and make a 7-cell 26650 bay like yours (how did you do that, by the way?) 

Think it would be beneficial if I thermal epoxied a small slug of aluminum to the IC?


----------



## mvyrmnd (Jul 22, 2012)

That's a 4D carrier with the guts stripped out, a piece of MDF for the top, a DC jack at the top running to both boards in parallel - I run it off a 5V 2A wall wart - then the two outputs are paralleled to give a 2A output and will balance charge the two 32650's that I stick in there.

In a pinch I can still plug into one of the USB ports and slow charge.

Oh, and a metric buttload of hot glue 

For yours, since all 7 cells will be used in series it will be beneficial to charge them in a big parallel batch, to make sure all the voltages are equalized.

I'd wire a 4A brick in parallel to 3 charging boards each, then all 6 outputs linked in parallel. That way you have 6A across 7 cells, and two mains inputs with a little bit of overhead. It also will give you a lot of output flexibility. You can put all 7 cells in and charge at 420 or 840mA per cell, or even load two cells and charge them at 1.5A each (with only one mains input turned on). If you set it up so that 18650's will sit comfortably, then you'll have a very powerful and flexible charger.

The IC's will get hot if there's a log of voltage being shed ie. your batteries ate at 3V and the input is 5V - they'll get toasty. As the battery voltage increases they'll cool off.


----------



## bstrickler (Jul 22, 2012)

Thanks for the info 

I decided to get a 380 watt MicroATX power supply instead of 2 4a wall warts, since it's going to run the same price after shipping (~$25), and I'll be able to get the full capabilities out of my B6, while still charging the 26650's via the other method (would've used the B6 for everything, but it only charges up to 6S Li-Ion, and I wasn't gonna spend a fortune on a charger).

~Brian

lovecpf


----------



## march.brown (Jul 22, 2012)

Just been looking on Ebay at 5V switch mode power supplies ... There are 2 amp (10 watts) ones for only $9-99 (£6-39) including postage ... There are some very good ones up to 5 amps and even higher for about £10 or so ... I might consider something like this.

It would be possible to feed several of these chargers from one PSU.
.


----------



## march.brown (Jul 26, 2012)

march.brown said:


> Just been looking on Ebay at 5V switch mode power supplies ... There are 2 amp (10 watts) ones for only $9-99 (£6-39) including postage ... There are some very good ones up to 5 amps and even higher for about £10 or so ... I might consider something like this.
> 
> It would be possible to feed several of these chargers from one PSU.


I have just sent for a switched-mode power supply off ebay ... It is 5V 4A (20W) ... Input voltage 100 to 264 Vac and the size is only 96mm X 58mm X 25mm ... It says that ripple and noise is less than 80 millivolts peak to peak ... I don't know how this compares with other 5V supplies ... It was from marcmart and it was only £5-19 including postage ... The intention is to use this to power two of the charging boards.

I have got to figure out the best way to connect the PSU to the charging boards ... I might possibly make up two mini USB cords and simply attatch them to the screw terminals on the PSU ... On the other hand I might add a couple of USB sockets to the PSU ... As they are coming from the Far East to the UK , I have about a month to think about it ... If needs be , I can use one of my wall-chargers to power a single board if the PSU comes before I have sussed out the 5V distribution ... I don't suppose that there is a set of ganged USB sockets available which could be hard-wired to the PSU ... This would be neater ... Decisions , decisions.
.


----------



## wshyang (Jul 26, 2012)

NoixPecan said:


> Not quite. Looking for an answer to the question in my previous post, I have read Cottonpickers' first thread about his USB chargers. In fact, his first design was based on the TP4054, but after selling a few chargers, he realized that the IC poorly implements (if at all) the CC/CV algorithm (despite what is specified in the datasheet). He ended up upgrading his design, by unsoldering the TP4054 from the charger board, and replacing it by the LTC4054. This IC from Linear (which the Chinese TP4054 tries to imitate) follows the CC/CV algorithm almost perfectly.
> 
> Since the charging board we are now discussing is based on the TP4056, a question rises. Does the TP4056 follow the CC/CV algorithm any better than the TP4054? Obviously, we cannot trust the datasheet. Should one of us own a logging multimeter, it would be a good idea to check how the board actually behaves.



Are the 2 ICs pin compatible?


----------



## RoGuE_StreaK (Jul 26, 2012)

wshyang said:


> Are the 2 ICs pin compatible?


From what I could see from the spec sheets, yes in both cases (4054 and 4056). Will double-check exact dimensions later today.


----------



## Lolaralph (Aug 4, 2012)

RoGuE_StreaK said:


> From what I could see from the spec sheets, yes in both cases (4054 and 4056). Will double-check exact dimensions later today.



I have some of each of the chargers discussed, the original board uses the 4056 which has 8 pins, the smaller board uses the 4054 and it only has 5 pins, hope this helps


----------



## march.brown (Aug 4, 2012)

Do you connect the supply first then put the battery in *OR* put the battery in first then put the supply in ?

My 1000mA HTC wall charger is inputting 5.11V on a thickish cable ... The 850mA wall charger is inputting 4.97V on a thin cable , so I've sent for a couple of the thicker cables and another HTC 1000mA charger ... Didn't try swopping the cables ... These new cables and charger will do till my 4A 5V switched mode PSU arrives from the Far East.

I'm not certain how long the charge should take using these modules on a 2400mAh cell.

I have been thinking of getting some more (better) 18650 batteries , possibly Senybor or Yezl or Xtar ... The price is right ... I can now probably justify getting some new batteries as my Wife has just bought four new dresses today that she didn't really need (birthday is later this month) ... I probably need four new (protected) 18650 batteries more than she needed the dresses (personally speaking) ... And my purchase would be a lot cheaper than hers !

Just noticed (after an hour) that one of the chargers blue LED is flicking on occasionally and the voltage is 4.19V ... That's the one with the thin cable ... The other is still charging and at 4.13V ... Blue flicking is getting quicker and the volts are flicking from 4.19V to 4.20V ... Got fed up and took the unprotected Ultrafire cells out.

Tried with my protected Ultrafires and a blue light still doesn't flicker even though the volts are up to 4.19V and 4.20V.

Can't understand why the protected cells are apparently acting better than the unprotected cells ... Perhaps it's age related ... The cells age not mine ! 

Gotta go now unfortunately , the dog's needs are greater than mine ... Will have another play tomorrow with more protected batteries.

Gotta get some better 18650's , I've made my mind up as long as she doesn't find out ... Wives have different priorities to men ... i've noticed this with all of my Wives ... I mean sequentially not concurrently ! ... Concurrently is illegal in the UK.
.


----------



## march.brown (Aug 5, 2012)

Found a small problem with the double battery holders.

The positive and negative connections are crimped with sort of rivets and are not a very good connection ... Couldn't understand why a bit of wire was open circuit on the positive end till I checked the rivets ... Rather than hammer the rivets to make a better connection , I will do it a different way with my next tries ... I have sent for some more of the double holders and will make some better (straight through) connections next time.

When my 4 Amp 5V PSU arrives , I will fit four USB sockets to it so I can use four one amp chargers if or when necessary ... Whilst this construction job is very interesting , I could have bought another charger for what I will be eventually spending ... I don't actually need any more Li-Ion chargers as I already have two double slot for 18650's and a four slot for the shorter ones.

Just a shame that items take a month to get to the UK from the Far East ... It makes the construction job take a long , long time.

Does the Postal system in the Far East cost peanuts ? ... Everything (plus postage) is really cheap ... How can they send five double battery holders to the UK for less than £4 including postage ?
.


----------



## Norm (Aug 5, 2012)

What do you guys think of this?




​

I bought a couple to see what they were like.

Pros : finished product, cost $8.95
Cons : my longer 18650s are a firm fit (keepower 3100mA)



> Description:
> 
> Charging current is 500mA when connected to a computer USB port.
> 
> ...












Click thumbs for a larger image











​


----------



## Lynx_Arc (Aug 6, 2012)

would be nicer if there was a cover over the battery so you could carry it around without worrying about the battery falling out


----------



## mvyrmnd (Aug 6, 2012)

I think we might be teetering in the brink of an era of cheap chargers that won't risk blowing up...


----------



## Norm (Aug 6, 2012)

Lynx_Arc said:


> would be nicer if there was a cover over the battery so you could carry it around without worrying about the battery falling out



A rubber band  might be OK, there are no exposed contacts when the battery in inserted, the spring as shown above is compressed totally back into the body.

Norm


----------



## NoixPecan (Aug 6, 2012)

Norm said:


> Pros : finished product


Is it not a cons? I mean, this thread is mostly about DIY. 
From what I have read around the web, notably on BudgetLightForum, the ML-102 charger seems praised by its owners. Good cheap stuff. It certainly deserves a dedicated thread, here on CPF. Maybe you could start one?


----------



## Lynx_Arc (Aug 6, 2012)

Norm said:


> A rubber band  might be OK, there are no exposed contacts when the battery in inserted, the spring as shown above is compressed totally back into the body.
> 
> Norm


Well the way it is I wouldn't want to give one to someone as a gift to charge their cellphone if they weren't a little battery savvy for fear they would not be careful with it.


----------



## Norm (Aug 6, 2012)

NoixPecan said:


> Is it not a cons? I mean, this thread is mostly about DIY.


I thought it was a good alternative for people not wanting to play about building something around one of the boards discussed and for not many more $$.

Norm


----------



## Lynx_Arc (Aug 6, 2012)

Norm said:


> I thought it was a good alternative for people not wanting to play about building something around one of the boards discussed and for not many more $$.
> 
> Norm


It does look good for the most compact utilitarian purpose for sure especially to just charge batteries instead of the more expensive chargers I've seen listed with their problems.


----------



## CMAG (Aug 6, 2012)

Got me 5 of these boards for $10 and change shipped, cool find Thanks:thumbsup: ordered a DC/DC buck for $4.25 7to24V in 5V 3A out now just got to find the time to play


----------



## Louisdidi (Aug 11, 2012)

Why is it not advisable to wire two these two 1A li ion charging board in parallel to get 2A charging current?


----------



## mvyrmnd (Aug 11, 2012)

Louisdidi said:


> Why is it not advisable to wire two these two 1A li ion charging board in parallel to get 2A charging current?



That's exactly what I've been doing for months with no issues...


----------



## Louisdidi (Aug 12, 2012)

mvyrmnd said:


> That's exactly what I've been doing for months with no issues...


Hi mvyrmnd,

I currently making a 2a solar charger for 6 unprotected Sanyo 18650. Btw for your setup u use protected or unprotected cells? Appreciate your advise on this matter.


----------



## march.brown (Aug 19, 2012)

Made up four of these and had to change my idea of building into a double 18650 battery holder ... My new 18700's won't fit in , so I am now using flying leads with magnets soldered on ... I charged up a couple of 18650's that I had discharged to 3.65V ... The temperature of the chip reached 62C ... It has now dropped to 55.5C and the voltage is 4.07V ... I will leave it another hour or so and see what the voltage goes up to.

That chip does get warm though ... I wonder if it is designed to take that sort of temperature !
.


----------



## march.brown (Aug 19, 2012)

march.brown said:


> Made up four of these and had to change my idea of building into a double 18650 battery holder ... My new 18700's won't fit in , so I am now using flying leads with magnets soldered on ... I charged up a couple of 18650's that I had discharged to 3.65V ... The temperature of the chip reached 62C ... It has now dropped to 55.5C and the voltage is 4.07V ... I will leave it another hour or so and see what the voltage goes up to.
> 
> That chip does get warm though ... I wonder if it is designed to take that sort of temperature !
> .


The blue LED is on when charging and the red comes on when charged ... Three chargers stop at 4.17 volts and one is 4.16V (when the Red LED comes on) ... The batteries used were one Ultrafire protected and two unprotected ... I've had these over two years and haven't checked the capacity ... They were OK when I first had them but now my Solarforce (on high) drops their voltage down to 3.6V or 3.7V in less than two hours ... It was about two and a half hours initially ...Good job I'm replacing them with Panasonic 3100's ... I will buy another couple next month and probably some more in a few months time ... I buy two at a time as that means the cost is less than the £15 UK import restriction.

When I have more time to play with the chargers , I will leave them on a bit longer and also check the rested voltages ... The good thing about using magnets is that if I clip paper-clips on my DMM leads , the magnets hold the leads in place ... I just have to switch the meter on when I need to check the voltage.
.


----------



## mvyrmnd (Aug 19, 2012)

march.brown said:


> The blue LED is on when charging and the red comes on when charged ... Three chargers stop at 4.17 volts and one is 4.16V (when the Red LED comes on) ... The batteries used were one Ultrafire protected and two unprotected ... I've had these over two years and haven't checked the capacity ... They were OK when I first had them but now my Solarforce (on high) drops their voltage down to 3.6V or 3.7V in less than two hours ... It was about two and a half hours initially ...Good job I'm replacing them with Panasonic 3100's ... I will buy another couple next month and probably some more in a few months time ... I buy two at a time as that means the cost is less than the £15 UK import restriction.
> 
> When I have more time to play with the chargers , I will leave them on a bit longer and also check the rested voltages ... The good thing about using magnets is that if I clip paper-clips on my DMM leads , the magnets hold the leads in place ... I just have to switch the meter on when I need to check the voltage.
> .



Wow, mine are the other way around - red when charging and blue when finished 

One of mine terminates at 4.17 and the other at 4.20. Because they're in parallel The whole charge ends at 4.20, just the last bit takes a bit longer


----------



## march.brown (Aug 20, 2012)

mvyrmnd said:


> Wow, mine are the other way around - red when charging and blue when finished
> 
> One of mine terminates at 4.17 and the other at 4.20. Because they're in parallel The whole charge ends at 4.20, just the last bit takes a bit longer


Initially I thought that the charger boards were not working as they were on red and nothing was happening ... The cell voltage (on charge) stayed the same if I took out the USB lead ... I used cells that were about 4.1 Volts at first and the red LED came on ... On *my* four boards , this means that the cells were already charged ... *Your* boards would have shown blue ... I will just have to remember that mine are blue when charging , then they go to "red for danger" to tell me to take them off ! ... I can't be bothered to send them back as they are OK other than the colour of the LED's.

If mine terminate at 4.16V or 4.17V , it means that the cells are only about 95% charged ... This doesn't worry me as I will be buying 3100mAh (protected) Panasonics from now on ... I have two already plus a couple of new Xtar 2600mAh (Sanyo) cells ... The intention is to buy two more Panasonics next month then two more in a couple of months time ... They came recorded delivery quite quickly from the Far East ... At less than £15 for two including postage , I can justify the expenditure ... The old Ultrafire 2400mAh's will then be retired from service.

I know that these chargers are not as pretty as a Pila , but if they work OK I will put off the evil day when (eventually) I have to (maybe) buy a Pila.
.


----------



## march.brown (Aug 20, 2012)

I discharged a 18650 to 3.67V and put it on charge at 1845hrs ... By 1900hrs the chip temperature was 63C and the voltage was showing 3.93V on charge ... At 1915hrs the temp was 62C and the voltage was 3.96.

I will keep a check on the temperature till it is charged ... It just seems a bit cruel to heat a chip up to that temperature.
.


----------



## Lynx_Arc (Aug 20, 2012)

march.brown said:


> I discharged a 18650 to 3.67V and put it on charge at 1845hrs ... By 1900hrs the chip temperature was 63C and the voltage was showing 3.93V on charge ... At 1915hrs the temp was 62C and the voltage was 3.96.
> 
> I will keep a check on the temperature till it is charged ... It just seems a bit cruel to heat a chip up to that temperature.
> .


65C is fine, some voltage regulators are spec'd to run up to 105C and computer chips I've seen at 65C with forced cooling/heatsinking on them at the time.


----------



## march.brown (Aug 20, 2012)

Lynx_Arc said:


> 65C is fine, some voltage regulators are spec'd to run up to 105C and computer chips I've seen at 65C with forced cooling/heatsinking on them at the time.


Thanks Lynx

I have just completed a proper charge from an 18650 cell that was 3.67V ... The cell voltage gradually built up to 4.20V and at the same time the temperature slowly dropped from 63C ... This took two hours ... The cell voltage stayed at 4.20V for over half an hour and I left it for one more hour and the voltage dropped to 4.17V ... I took the cell off charge and one hour later it was still 4.17V ... This seems to me to be a proper CC/CV charger ... Great for the price.
.


----------



## mvyrmnd (Aug 20, 2012)

You're discovering what we learned earlier in the thread, Mr. Brown.

These are good little devices and allow people to create flexible, custom chargers to suit their needs.


----------



## march.brown (Aug 20, 2012)

mvyrmnd said:


> You're discovering what we learned earlier in the thread, Mr. Brown.
> 
> These are good little devices and allow people to create flexible, custom chargers to suit their needs.



I was a bit worried about the heat given off by the small chip ... At my age , as a boy , I was studying digital computers with those new-fangled transistors and diodes ... We had to build gates with discrete components , use pulse steering diodes etc ... Our new audio amplifiers had Mullard OC71's and OC72's ... The computer at English Electric (Kidsgrove) had thermionic valves and the computer covered several rooms ... The new (discrete-component solid state) computer created a major problem ... Because the office block was heated by the waste heat from the thermionic valves , a central-heating system had to be put in.

Anyway , I am relieved to find out that these chips are capable of running hot ... Sorry if I repeated things that were mentioned earlier ... It's probably age-related ... Well , that's what my latest Wife says.


----------



## mvyrmnd (Aug 20, 2012)

march.brown said:


> I was a bit worried about the heat given off by the small chip ... At my age , as a boy , I was studying digital computers with those new-fangled transistors and diodes ... We had to build gates with discrete components , use pulse steering diodes etc ... Our new audio amplifiers had Mullard OC71's and OC72's ... The computer at English Electric (Kidsgrove) had thermionic valves and the computer covered several rooms ... The new (discrete-component solid state) computer created a major problem ... Because the office block was heated by the waste heat from the thermionic valves , a central-heating system had to be put in.
> 
> Anyway , I am relieved to find out that these chips are capable of running hot ... Sorry if I repeated things that were mentioned earlier ... It's probably age-related ... Well , that's what my latest Wife says.


All good 

I noticed the heat too, when I first started using them.

I had posted my "workaround" earlier, but the post was lost in the recent server crash.

I use a 2A 5V "wall-wart" (OCV of nearly 6V, 5V under load) charger to run my two boards. When the batteries are very low, ie. sub 3.5V, the voltage differential is quite high, and that poor little chip has to shed a lot of heat. When this is the case, I charge from my iPad charger (2A still, but OCV of 5V and 4-and-a-bit volts under load) but the loaded voltage from the iPad charger is much lower, therefore a lower differential, therfore less heat. Once the batteries are half-charged, I go back to the wall-wart as it charges a bit more quickly from there.


----------



## march.brown (Aug 21, 2012)

mvyrmnd said:


> All good
> 
> I noticed the heat too, when I first started using them.
> 
> ...



The The 5 Volt , 4 Amp switch-mode PSU that I will be using has a trimmer to set the voltage accurately ... I'm going to power four USB sockets from this PSU and I might well trim the voltage down to a bit under 5 volts , it might save the chip from getting too warm ... Although I am going to connect four USB sockets to the PSU , I will probably only ever charge two cells at the same time ... It does seem though (from other posts) that these chips are capable of running hot ... Should we therefore just bury our heads in the sand and let the chips run hot for the first 90 minutes or so ?

Am I letting my sympathy for the chip over-rule suggestions by other (more experienced) posters ?
.


As an old (in all senses of the word) electronics engineer , I still have some sympathy for little chips running at high temperatures ... Having been retired for over eighteen years , I am not up with the latest technology of integrated circuits ... If people tell me that these chips will withstand high temperatures , then who am I to argue with them !
.


----------



## mvyrmnd (Aug 21, 2012)

I think your setup would work better, with you trimming the voltage. I did read somewhere that the closer to 4.2V the input, the faster the charge.


----------



## march.brown (Aug 21, 2012)

mvyrmnd said:


> I think your setup would work better, with you trimming the voltage. I did read somewhere that the closer to 4.2V the input, the faster the charge.


When my (two double) USB sockets arrive , I will wire them up to the PSU , put a couple of batteries on charge and have a tweak at the voltage adjustment ... It might take a while as the sockets are coming from the Far East ... The sockets are two on a white plastic fascia plate (like a double light switch) and I will be mounting two of these plates back-to-back to give me the four USB sockets ... Then there will be a short cable to the PSU ... Should look pretty and be functional as well ... It's just a matter of waiting for delivery now ... In the mean-time I will use the HTC one amp wall chargers.
.


----------



## HKJ (Aug 21, 2012)

march.brown said:


> It does seem though (from other posts) that these chips are capable of running hot ... Should we therefore just bury our heads in the sand and let the chips run hot for the first 90 minutes or so ?



Maybe add a heatsink under the PCB, just be careful with the isolation.

Generally power components can handle up to about 150 degree's inside the component, but it reduces the lifetime and can be hard on the surroundings.


----------



## march.brown (Aug 21, 2012)

HKJ said:


> Maybe add a heatsink under the PCB, just be careful with the isolation.
> 
> Generally power components can handle up to about 150 degree's inside the component, but it reduces the lifetime and can be hard on the surroundings.


The first full test on charger one showed a high temperature of 63C after 15 minutes but this was using a fairly thick 30cm USB lead ... Using one of those one metre extendable thin leads , the temperature on charger two was only 41.5C after half an hour using the same PSU and the cell voltage didn't build up very quickly.

I then swopped the thin lead for the thick one and the temperature of the chip is on the way up as happened on charger one ... It seems that I will have to use the thicker lead in future ... After 15 minutes using the thick lead , the voltage is building up nicely (4.10V) and the temperature was 52.5C ... Another 15 minutes on and the Voltage was 4.13V but the temperature had dropped to 42.5C ... It seems that by putting the charger on the thin USB lead for the first half hour , reduced the maximum temperature by ten degrees ... I will let the charger complete the charge to make sure that the final voltage is within the 4.20 limit as on charger one.

One problem is that these Ultrafire cells are fairly old ones and the results might be different on newer cells ... I will have a better idea of the charger performance when my two (more) new Panasonic 3100mAh arrive from the Far East in a couple of weeks
.


----------



## Norm (Aug 21, 2012)

I'm confident that the difference of 10c isn't worth the bother.

Cheers Norm


----------



## march.brown (Aug 21, 2012)

Norm said:


> I'm confident that the difference of 10c isn't worth the bother.
> 
> Cheers Norm


Thanks Norm , I guess I will just monitor the temperature in case (?) ... Probably ignore the temperature of the chip unless it starts to give off steam (only joking).

I'm glad that I've decided to upgrade my 18650/18700's ... My Ultrafires are playing up a bit now ... They are less than three years old and have not had too much use except for recently when discharged and recharged to check that my four cheap battery boards are charging OK ... My two unprotected Ultrafires won't now charge up fully even on the Soshine charger ... They get up to 4.20 volts and the charged LED comes on ... When removed and rested , they only read 4.00V and 4.04V ... One protected reads 4.10V when rested , the other four read 4.19V ... I think the two unprotected can be disposed of and I will keep an eye on the 4.10V cell ... I will keep the four good Ultrafires mainly for the Solarforce L2i's and my Maglite 2D with Fusion 36 as the cells are about 1.5 mm shorter than the protected Panasonics ... The Panasonics will fit the L2i , but I would have to slacken the torch head a turn or so (or trim the spring) to make up for it ... I might even go back to using six Eneloop AA's again in the Mag 2D ... I am waiting for two more Panasonic 3100mAh's to arrive and I will order a couple more in a month or so ... I have to be prepared for when the other Ultrafires eventually need replacing which might be sooner than later based on the fact that they are all the same age.

Thanks again for the replies about the high chip temperature ... I'm happier now (a bit). 
.


----------



## NoixPecan (Aug 23, 2012)

NoixPecan said:


> Does the TP4056 follow the CC/CV algorithm any better than the TP4054? Obviously, we cannot trust the datasheet.


Thanks to HKJ and his recent review of the ML-102 charger (in that thread) we now know that the TP4057 is not better than the TP4054 in that respect, which leaves little hope for the TP4056.

However, as HKJ rightly said:


HKJ said:


> The charge curve does not look like a CC/CV charger, but the only disadvantage with this type of curve is the slower charge speed, the final result will be just as good as a CC/CV charger.


----------



## march.brown (Aug 24, 2012)

The Blue LED is on when charging and the Red comes on when charged ... 
Does anyone else have this problem.
Everyone else seems to have Red LED for Charging and Blue LED for finished.
The Blue LED is the one on the left when viewed with the USB socket on the left.
The Red LED is the one on the right beside the battery connection.
I have written to the seller but I don't think he quite understands the problem.
It just seems wrong to have a Blue LED on whilst charging.


----------



## march.brown (Aug 24, 2012)

march.brown said:


> The Blue LED is on when charging and the Red comes on when charged ...
> Does anyone else have this problem.
> Everyone else seems to have Red LED for Charging and Blue LED for finished.
> The Blue LED is the one on the left when viewed with the USB socket on the left.
> ...


SILLY ME !

I have just read the Ebay specification and it actually says that the Blue LED is on whilst charging and the Red LED is on when charged ... 

Am I the only one with a Blue charging LED and a Red finished LED ?

I think I need a drink !
.


----------



## ToddC (Aug 24, 2012)

march.brown: 
1) The datasheet (http://pds24.egloos.com/pds/201206/07/08/TP4056Eng.pdf) lists max Tj=145C, which is well above the temperatures you measured. It also lists an operating environment of -40C to 85C, though the "guaranteed" operating range would be smaller. They don't have it listed in the datasheet but I suspect it's around 0C-65C. 
2) From one of my posts earlier in this thread: "The only issue I noted is the LEDs are swapped vs the ebay listing. The charging position is blue and the completed is red."


----------



## Lynx_Arc (Aug 24, 2012)

ToddC said:


> march.brown:
> 1) The datasheet (http://pds24.egloos.com/pds/201206/07/08/TP4056Eng.pdf) lists max Tj=145C, which is well above the temperatures you measured. It also lists an operating environment of -40C to 85C, though the "guaranteed" operating range would be smaller. They don't have it listed in the datasheet but I suspect it's around 0C-65C.
> 2) From one of my posts earlier in this thread: "The only issue I noted is the LEDs are swapped vs the ebay listing. The charging position is blue and the completed is red."


Can't you just unsolder them and swap them? (may have to change a resistor perhaps).


----------



## Norm (Aug 24, 2012)

Lynx_Arc said:


> Can't you just unsolder them and swap them? (may have to change a resistor perhaps).


Does it matter which the LED is used to indicate charging?

Norm


----------



## Lynx_Arc (Aug 24, 2012)

Norm said:


> Does it matter which the LED is used to indicate charging?
> 
> Norm



Not if all your devices are similar. I suppose if you got boards from 2 different batches and the LEDs were different/swapped it could get confusing.


----------



## march.brown (Aug 26, 2012)

ToddC said:


> march.brown:
> 1) The datasheet (http://pds24.egloos.com/pds/201206/07/08/TP4056Eng.pdf) lists max Tj=145C, which is well above the temperatures you measured. It also lists an operating environment of -40C to 85C, though the "guaranteed" operating range would be smaller. They don't have it listed in the datasheet but I suspect it's around 0C-65C.
> 2) From one of my posts earlier in this thread: "The only issue I noted is the LEDs are swapped vs the ebay listing. The charging position is blue and the completed is red."


Hi Todd ... Many thanks for the information about temperature ... If the operating environment is quoted at up to 65C then my chip casing temperature is well below that when working in a 25C room ... A Tj of 145C is far hotter than I would have expected , so I am very happy now ... If the internals are capable of working at 145C , the casing of the chip would be far hotter than my measurements (I guess).

I have had several Emails from the seller and he insists that it is a Blue LED for charging and a Red LED for charging completed ... All four of mine are the same ... I don't know whether there is a standard for LED colours on chargers , but all my others charge on Red ... They terminate on either green or blue ... I will live with the four chargers as (apart from LED colour) , they are working correctly ... Since the temperature problem has been sorted , I am very happy.

My two double USB sockets have arrived (like double light switches) and I will mount these back to back and feed them from my 5V 4A switch-mode PSU ... I will be able to use all four chargers if needed ... I doubt whether I will need more than two , but it's a matter of "just in case".

I won't mess about with changing/swopping the LED's ... I will just label the chargers as being "Blue for Being Charged , Red for Ready"... The Ebay listing now says Blue for on charge.

Thanks again
.


----------



## czAtlantis (Aug 26, 2012)

Previous batch had red=charging, blue=complete (I ordered only one bord to test) Newer batch has red=complete, blue=charging. It seems to me that some Chinese just accidentally swapped reels with LEDs and they are now like "it is not a bug, it is a feature".
I de-soldered and changed LEDs but it is quite hard not to damage those small LEDs.

Also I owuld appreciate version with micro-USB because I don't use mini-USB on many things nowdays.


----------



## HotWire (Sep 3, 2012)

I've got one hooked up with magnets. It has terminated at 4.16v and 4.17v on several different li ion 3.7v cells. I've very pleased with the result. Mine lights the *blue *LED when charging and the *red* LED when done. I would note, however, that one charger for a single cell is not enough. I've ordered 3 more with battery holders and planning on assembling a 4-battery independent charger from them. This is a great thread!


----------



## funkychateau (Sep 19, 2012)

Where are you guys finding these boards at $2 shipped? Best Ebay is about $4, or auction beginning at $0.01 but $3 shipping.


----------



## Norm (Sep 19, 2012)

Ebay Item number: 300776343223

Norm


----------



## funkychateau (Sep 19, 2012)

Thanks!


----------



## HKJ (Oct 8, 2012)

I have posted of review of this board:


----------



## Changchung (Oct 8, 2012)

HKJ said:


> I have posted of review of this board:



Very well test and review... Thanks a lot again...


SFMI4UT


----------



## NoixPecan (Oct 8, 2012)

Wow, thank you HKJ ! A great review, as always, and very informative. After Cottonpickers' report of the TP4054 IC not really doing CC/CV, and your report of the TP4057 not really doing it either, I expected a similar behaviour from the TP4056. But your experiments prove that the TP4056 actually does CC/CV, which is a nice surprise.  For DIYers, that $2 charging board is a little gem...


----------



## HKJ (Oct 8, 2012)

NoixPecan said:


> Wow, thank you HKJ ! A great review, as always, and very informative. After Cottonpickers' report of the TP4054 IC not really doing CC/CV, and your report of the TP4057 not really doing it either, I expected a similar behaviour from the TP4056. But your experiments prove that the TP4056 actually does CC/CV, which is a nice surprise.  For DIYers, that $2 charging board is a little gem...



Of the 3 chips the TP4056 is closest to a full CC/CV, but all of the chips are using a good charge algorithm, the deviation from a true CC/CV is just slowing the charge speed down.


----------



## NoixPecan (Oct 8, 2012)

I agree that their algorithm is safe, but whether it is good enough depends on the intended application. For some applications, both the charging time and the peak current are critical.

In any case, a problem is that the TP4054 and the TP4057 do not deliver what is stated in their datasheet. Should the TP4056 behave the same, I would have asked "true CC/CV" to be removed from the title of this thread...


----------



## march.brown (Oct 9, 2012)

NoixPecan said:


> I agree that their algorithm is safe, but whether it is good enough depends on the intended application. For some applications, both the charging time and the peak current are critical.
> 
> In any case, a problem is that the TP4054 and the TP4057 do not deliver what is stated in their datasheet. Should the TP4056 behave the same, I would have asked "true CC/CV" to be removed from the title of this thread...


From the graphs shown by HKJ , it shows that the transition from CC to CV is fairly gentle , but is still showing CC/CV characteristics ... Not ideal , but for most applications it seems to be perfectly OK.

The board then halts the CV process and (other than a few micro-amps) cuts off the charge completely ... Perfect.

To those people where charging time is critical then they could try two or three of these boards in parallel ... The peak current during the CC could easily be adjusted by changing the resistors to give the required level ... Some posters have already tried this with no problems.

My own very slightl worry (?) is the fact that the chip heats up to about 65C in my four chargers ... Admittedly this is only for the early part of the charge and the data sheet says that this is within limits ... A simple heat-sink as shown by HKJ would solve this ... I was considering adding a small heatsink to my four charger boards but as I have had no problems yet , I still feel inclined to leave them as they are ... Two boards in parallel with the resistors changed would solve this easily as I only need to charge my cells at one amp ... Charge time is not really important to me.
.


----------



## NoixPecan (Oct 9, 2012)

march.brown said:


> From the graphs shown by HKJ , it shows that the transition from CC to CV is fairly gentle , but is still showing CC/CV characteristics ... Not ideal , but for most applications it seems to be perfectly OK.


Yes, I was replying HKJ about the algorithms of the TP4054 and the TP4057, but as I said in post #159, I am perfectly happy with that of the TP4056. 

And thanks to HKJ and his review, we know that we will have to be very careful about the battery polarity.


----------



## shadowjk (Oct 9, 2012)

If we assume that the chip is true CC/CV, and we use the USB=5.5V HS graph, we can derive a theoretical total resistance of about 0.170 Ohm between the chip and battery, which would distort the charging profile in this way.


----------



## bstrickler (Nov 6, 2012)

Norm said:


> Ebay Item number: 300776343223
> 
> Norm



I've tried ordering the boards from that seller, but the first package, and the second package never made it to my house. Didn't leave any feedback, because it would be wrong to leave negative feedback on someone who followed through with their side of the deal.



Anyone ordering a few boards soon? I'll send you the $ for the quantity I want, so maybe this time they'll make it to my house.

item # is 300806707489


----------



## Norm (Nov 6, 2012)

bstrickler said:


> Anyone ordering a few boards soon? I'll send you the $ for the quantity I want, so maybe this time they'll make it to my house.
> 
> item # is 300806707489


I'm not too sure adding another step to the equation is going to help.

Good luck receiving them however you choose to proceed.

Norm


----------



## bstrickler (Nov 7, 2012)

Norm said:


> I'm not too sure adding another step to the equation is going to help.
> 
> Good luck receiving them however you choose to proceed.
> 
> Norm



Thanks.

I just figure that maybe if I add insurance to it, it might help, or have it shipped to a friend, and see if it vanishes from their mailmans possession, too. (mine said "out for delivery" and was never updated after that, and at the main post office, they said they couldn't do anything.)


----------



## Masure (Nov 18, 2012)

Hi,

I plan to use one of those small charge boards and here is my noob question : 

Is it possible to leave a cell connected to the charge board while it is lighting a led ? Won't it damage the charge board ?


----------



## Lynx_Arc (Nov 18, 2012)

Masure said:


> Hi,
> 
> I plan to use one of those small charge boards and here is my noob question :
> 
> Is it possible to leave a cell connected to the charge board while it is lighting a led ? Won't it damage the charge board ?


If you are talking about an LED connected in parallel to the charge board (and battery) it probably will effect how the battery is charged possibly upsetting the termination algorithm. Not a good idea IMO.


----------



## malow (Nov 18, 2012)

is there any cheap charging boards like this, but for LiFePO4? can't find any on ebay and other sites....


----------



## march.brown (Nov 19, 2012)

bstrickler said:


> I've tried ordering the boards from that seller, but the first package, and the second package never made it to my house. Didn't leave any feedback, because it would be wrong to leave negative feedback on someone who followed through with their side of the deal.


In the last few months , I have had five items "disappear" in the post from the Far East to the UK ... I have had my money refunded in all but one case , but it is still a "pain in the rear" to lose a month or two (particularly at my age) and then have to reorder the item.

One item was ordered and when it didn't arrive after 30 days , I informed the seller ... I agreed to let him resend the item ... That did not arrive either , but Ebay could not get me a refund as I had gone over the "time limit" ... Recently I sent for two Panasonic 18650 batteries which didn't arrive ... In the sellers reply , he told me that a refund would be given as it seems that the batteries were sent in error to America rather than the UK ... I waited a few more days and re-ordered ... These ones came OK in 14 days , signed for.

So over the last six years or more , all my losses were in the last few months ... Are any other members having the same problems with Far Eastern deliveries ?
.


----------



## nofearek9 (Nov 19, 2012)

also order that board ,after 1,5 month contacted the seller and he resend it now its almost 3 months waiting and still didnt arrived.


----------



## Changchung (Nov 19, 2012)

I just order yesterday two of this; item number 140826274091

1,67$ each shipped

I hope receive it before christmas.

In the last two months two orders was lost in mail shipped from china and I receive a full refund, if I recieve this orders I pay back to the sellers, if dosent show up I order it next year...


Sent from my phone with camera with flash and internet on it...


----------



## emergencyled (Nov 20, 2012)

I am to still waiting for mine to arrive. it been just over approx 3 to 4 weeks ebayer keep asking if i got it i say no still waiting. I have to check send out date to see exactly how long its been.


----------



## Lips (Nov 21, 2012)

Ordered a few of these boards to recharge single Lith Ion Power Tools hopefully from the below device out in the field. 





These 5v charges ( Item 170917328804 ) are around $12.99 and are awesome. You can charge devices or charge 4 x 18650 inside (2amp to 18650's if you have micro usb charger at that rate) . Comes in different colors...
*It even has a led flashlight built in!* This thing has been great in the field and you can select charge devices at 500ma, 1000ma, 2amp. Maybe one of you tech guys could figure out if it is cc/cv and good alternative for charging 4 batteries.



*Features : *
--Charging Input: micro usb：5v/2A
--Output:：usb1+usb2=0.5A/1A/2A
--Material: Plastic
--Batteries: 4ocs 18650 lithium batteries (not included)
--Can charge most cell phones as well as iPhone,iPod,iPad and other Apple products
--Bright light LED energy-saving lamps


----------



## Masure (Nov 22, 2012)

Could someone please give me some dimensions of the board thickness (+ components) in different locations ? I would need need these in 3 points for a tight design I'm working on.






A. thickness with tp4056
B. thickness of board alone
C. thickness with ??? 

Thanks for help !


----------



## fvdk (Nov 22, 2012)

A = 2.46 mm
B = 1.01 mm
C = 2.61 mm



Masure said:


> Could someone please give me some dimensions of the board thickness (+ components) in different locations ? I would need need these in 3 points for a tight design I'm working on.
> 
> 
> 
> ...


----------



## march.brown (Nov 22, 2012)

Masure said:


> Could someone please give me some dimensions of the board thickness (+ components) in different locations ? I would need need these in 3 points for a tight design I'm working on.
> 
> 
> 
> ...


The thickest place is where the Mini-USB socket is fitted ... 5.02mm on mine.

If you are going to fit this into a tight space , you will need to ventilate the chip as it gets very warm ... I've sent off for some small heatsinks (to fit to the reverse of the board) and I use my charger board uncovered ... The chip is able to run very hot , but apparently it will then reduce the charging current ... I have four of these and I now do not use any other means of charging my !8650's ... I only charge mine at one amp though.

If you are putting your boards in a case , ideally one side of it could be aluminium ... The reverse of the charger board could be stuck to the aluminium using double-sided tape to give the board some cooling ... I will be using Sekisui 5760 tape to hold my heatsinks in place.

Good luck with your project.
.


----------



## JRJ (Nov 22, 2012)

Just ordered a couple of these boards for projects as well as some 1s-6s LED Lipo Battery Voltage Checker Indicator, couple of noob questions if you dont mind?

Easiest wasy to wire the voltage checker in?

Best gauge of wire to use between charger and batteries?

Thanks


----------



## Masure (Nov 23, 2012)

Thanks for the dimensions. I didn't asked for the thickness with mini usb connector cause I already planned to remove it .

@march.brown

I'll do exactly what you suggest for thermal management. Thermal adhesive tape + aluminium housing contact.


----------



## ToddC (Nov 24, 2012)

I took a stab at making a self contained cradle since I only use this for 14500 and didn't like the croc and magnet setup I made. I gutted a 4-AA serial battery case except for an end slot, ran charger wires out the second from the end and back into the last slot to be soldered. The holder melts easily and I had to remelt it to get the positive contact back in and aligned. I then covered the mess I made (and the short external wire run) with electrical tape and used hot glue to keep the charger in place. Just thought I throw this out there in case someone is looking for ideas. One could also not gut as much and install jumpers to clip a multimeter to.


----------



## Norm (Dec 3, 2012)

PCB Charging Board For 3 Packs 3.7V Li-ion Lithium 18650 Recharge Battery 4A-5A

Ebay Item number: 300807082644

Max. 4-5A PCB Charger for 4 Packs 3.7V Li-ion Li Lithium 18650 Recharge Battery 

Ebay Item number: 260858172522

What do you think?

Norm


----------



## Changchung (Jan 15, 2013)

*What I am doing wrong Mini USB 1amp Charger*

Hi guys, I just receive two 5V Mini USB 1A Lithium Battery Charging Board Charger Module from china bought in ebay, I put the wires with magnets to the output, try with two USB wires, try in my pc, try in tho 110v USB adapters, both have 1amp output and when I connect the battery to the charger the Blue Led go on, must be the Red one showing that is charging, the battery is in 3.80volts

I leave the battery for almost 20 minutes and checking the voltage with a DMM I dont see any difference, like it is not charging, if this thing charge with 1amp I must see some increase in the voltage in the battery right???


----------



## spencer (Jan 15, 2013)

*Re: What I am doing wrong Mini USB 1amp Charger*

This could be one of those cases where you get what you pay for. China has a reputation for making stuff that is not worth purchasing or stuff that straight up doesn't work. Don't get me wrong, I'm not saying that everything made in China is junk (in fact they can turn out some very respectable products) but they can also have very poor QC and workmanship.

Things to try:
ensure that the board outputs the correct polarity with a DMM (check that red is positive and black is negative or similar)
see if the battery is charging when the blue light is on (red and blue LED could be mixed up)


----------



## Changchung (Jan 15, 2013)

*Re: What I am doing wrong Mini USB 1amp Charger*



spencer said:


> This could be one of those cases where you get what you pay for. China has a reputation for making stuff that is not worth purchasing or stuff that straight up doesn't work. Don't get me wrong, I'm not saying that everything made in China is junk (in fact they can turn out some very respectable products) but they can also have very poor QC and workmanship.
> 
> Things to try:
> ensure that the board outputs the correct polarity with a DMM (check that red is positive and black is negative or similar)
> see if the battery is charging when the blue light is on (red and blue LED could be mixed up)



Thanks... I will never know if this one was bad, I connect the battery backwards and I am sure that I kill it... 

I am going to test the second one...


----------



## mvyrmnd (Jan 15, 2013)

*Re: What I am doing wrong Mini USB 1amp Charger*

Some of these boards have the LED's on backwards. Mine go red to charge, and blue when complete. Some go blue to charge, and red when complete.

Power it up without the battery attached, see what colour it is. Attach the battery. If the colour changes, then you know which way around it is 

These boards have no reverse polarity protection. If you put the battery in backwards, you'll know about it, because one of components wil burn.

Have a good read of this thread.


----------



## Changchung (Jan 15, 2013)

mvyrmnd said:


> Some of these boards have the LED's on backwards. Mine go red to charge, and blue when complete. Some go blue to charge, and red when complete.
> 
> Power it up without the battery attached, see what colour it is. Attach the battery. If the colour changes, then you know which way around it is
> 
> These boards have no reverse polarity protection. If you put the battery in backwards, you'll know about it, because one of components wil burn.



Thanks, I just make that test, blue is charging and red must show when it is charge, but , my concern was that I leave the battery for almost 20 minutes and checking the voltage with a DMM I dont see any difference, like it is not charging, if this thing charge with 1amp I must see some increase in the voltage in the battery right???

The first one is officially burn... :shakehead


----------



## mvyrmnd (Jan 15, 2013)

Changchung said:


> Thanks, I just make that test, blue is charging and red must show when it is charge, but , my concern was that I leave the battery for almost 20 minutes and checking the voltage with a DMM I dont see any difference, like it is not charging, if this thing charge with 1amp I must see some increase in the voltage in the battery right???
> 
> The first one is officially burn... :shakehead



20 minutes should be long enough to see a voltage rise... but if it's not changing then at least it's not going to explode if you leave it for longer.

The other thing to remember is that some USB ports won't supply full current unless communicated with properly. If you've got it plugged into your computer, it won't be 1A, it'll only be getting 500mA.

Leave it for an hour and see if it charges. you simply might not be getting as much input amps as you think you are.

I use a 5V/2A wall-wart for mine rather than a USB input, to guarantee my input power.


----------



## Changchung (Jan 18, 2013)

mvyrmnd said:


> 20 minutes should be long enough to see a voltage rise... but if it's not changing then at least it's not going to explode if you leave it for longer.
> 
> The other thing to remember is that some USB ports won't supply full current unless communicated with properly. If you've got it plugged into your computer, it won't be 1A, it'll only be getting 500mA.
> 
> ...



Hi, well, the problem was the USB power, so, I decide to use a 3amp DC/DC adjustable converter.

Charge this batt in like 40 minutes


----------



## mvyrmnd (Jan 18, 2013)

Changchung said:


> Hi, well, the problem was the USB power, so, I decide to use a 3amp DC/DC adjustable converter.
> 
> Charge this batt in like 40 minutes



There you go!


----------



## Changchung (Jan 19, 2013)

mvyrmnd said:


> There you go!



Thanks...


----------



## javor (Jan 19, 2013)

Changchung said:


> Hi, well, the problem was the USB power, so, I decide to use a 3amp DC/DC adjustable converter.
> 
> Charge this batt in like 40 minutes



I see you are using voltmeter. Which model ? Are you satisfied with precision and range ?


----------



## VidPro (Jan 19, 2013)

Norm said:


> PCB Charging Board For 3 Packs 3.7V Li-ion Lithium 18650 Recharge Battery 4A-5A
> 
> Ebay Item number: 300807082644



Me thinks that this is not so much a "charging board" but is a 3x li-ion pack protection curcuit? I have a 4s pack protection curcuit and the layout is very very close to the same as this, including chip shape and number and size and connection points.
On the data sheet i do not see any provided rate of charge information, or any indication that it has a current thingee or voltage thingee other than cut-offs. 

5 Battery connection points, which should relate to 4 batteries, not 3. *B3-: no use *(explains that) The title is the thing that makes it confusing.

Ya wouldnt charge most li-ion at 5A and a wee little board like that probably couldnt do all that CC/CV stuff at 5A , but a 5amp protection curcuit looks just like that. and costs about that price also. It is either a very poor title, or both pictures are incorrect for what your getting.


----------



## Changchung (Jan 19, 2013)

javor said:


> I see you are using voltmeter. Which model ? Are you satisfied with precision and range ?



Well, last night I have the same doubt, so, I make a measurent with a DMM and I see some difference, when the small display show 4,12v in the DMM I get 4,08v

Tomorrow I will test others two voltmeters to see what I get...

I buy it in ebay, you can find it in buyincoins as well.


Sent from my phone with camera with flash and internet on it...


----------



## jbeebo (Feb 1, 2013)

Hi guys, new here please go easy on me!

Was wondering if anyone has tried these really cool boards in a 3S lipo config. I.e. hook them in series between a 13-15Vdc source and run them to the balance leads of the 3S.

If 3 chargers: lowest voltage one closest to ground potential = "A", middle = "B", highest voltage one closest to 14V source = "C". IN_GND of A connected to GND of power source. In+ of A connected to IN_GND of B. IN+ of B connected to IN_GND of C. IN+ of C connected to +14V of power source. Same basic config on output side going to balance lead.

I imagine you'd need some power resistor divider network?

One last question...I see the TP4056 has a fixed termination voltage of 4.2V. For charging LiFe battery with termination of 3.7V, any reason why could not use 1N400x series diode drop to get voltage to battery correct?

Would love to hear opinions of folks much smarter than I.


----------



## MikeAusC (Feb 1, 2013)

jbeebo said:


> . . . . Was wondering if anyone has tried these really cool boards in a 3S lipo config. I.e. hook them in series between a 13-15Vdc source and run them to the balance leads of the 3S. . . .



If you're talking about the Single-LiIon charging boards, that definitely will NOT work.

The only way you could use 3 separate charging boards, would be if you had three floating power sources e.g. three plugpacks/wallwarts which are isolated by their internal transformers. Three USB outlets on a laptop all have their GND side tied together, so you would be shorting out two of the cells in a 3S pack.

To charge LiIons in a Series pack, you need a charging board designed specifically for that.


----------



## MikeAusC (Feb 1, 2013)

Norm said:


> Ebay Item number: 300776343223
> 
> Norm



These boards are also available from DX for $3US - sku 187117


----------



## Changchung (Feb 1, 2013)

MikeAusC said:


> These boards are also available from DX for $3US - sku 187117



To expences...


Sent from my phone with camera with flash and internet on it...


----------



## Thr3Evo (Apr 5, 2013)

My idea of incorporating these boards:





More pictures  here


----------



## MikeAusC (Apr 5, 2013)

jbeebo said:


> . . . . I see the TP4056 has a fixed termination voltage of 4.2V. For charging LiFe battery with termination of 3.7V, any reason why could not use 1N400x series diode drop to get voltage to battery correct? . . .



Because the voltage drop across a diode depends on the current flowing through it. As the battery approached full charge the current would reduce and the voltage across the diode would reduce, applying excess voltage to the battery.


----------



## bhsimon (Jun 2, 2013)

Hello everyone. New to forum and would like to say how much I have enjoyed reading this thread. It has been really inspirational.

I am working on a little project using this board. I am very new to electronics, so please excuse my ignorance.

I have made a battery pack from 3 x 25500 cells wired in parallel. For my project, these cannot be disassembled when charging is required.

How do I use this board to charge the cells? Can I just treat them as if they were one cell?
If I wire a charger to each cell separately, will that work?

Thank you for any assistance you may be able to provide.


----------



## Knight_Light (Jun 3, 2013)

bhsimon said:


> Hello everyone. New to forum and would like to say how much I have enjoyed reading this thread. It has been really inspirational.
> 
> I am working on a little project using this board. I am very new to electronics, so please excuse my ignorance.
> 
> ...


 
Welcome to the forum. When you wire batteries in parallel such as you did for your project you are essentially creating one large battery. So what you need to do is add up the capacities of the batteries and that will give you your total capacity for your pack. Lithium batteries tend to even each other out when wired in parallel, so you can just treat it as one large battery when you are charging.

Just please be sure to start with high-quality batteries that are brand-new and have similar capacities (even though they are in parallel). So you would charge this battery pack simply by just connecting to it (whatever way you’ve designed it) with your charger not by charging each cell separately.

Before anybody answers the other questions you should provide us with the chemistry of the battery. 

Also keep in mind you have now created one large battery which means you should charge it at a higher charge rate. You can look at the recommended charge rate on the datasheet for those batteries. Usually .6C is considered ideal for lithiums.

It will work at a lower charge rate but you may or may not have a problem with the charge terminating. So you will have to monitor the battery and see if it terminates properly.


----------



## hiuintahs (Jun 3, 2013)

bhsimon said:


> ...........I have made a battery pack from 3 x 25500 cells wired in parallel. For my project, these cannot be disassembled when charging is required.
> 
> How do I use this board to charge the cells? Can I just treat them as if they were one cell?
> If I wire a charger to each cell separately, will that work?


 

Since your cells are in parallel, they will just look like one cell with triple the current capacity. So that means it will take 3 times as long to charge with one board at a fixed charging current.

You could wire a charger to each cell but then you'd have to disconnect each of the cells in the pack so that the individual charging boards do not fight each other. That sort of defeats your purpose of not being able to disassemble when charging.

Hope that helps.


----------



## bhsimon (Jun 3, 2013)

Knight_Light said:


> Before anybody answers the other questions you should provide us with the chemistry of the battery.
> 
> Also keep in mind you have now created one large battery which means you should charge it at a higher charge rate. You can look at the recommended charge rate on the datasheet for those batteries. Usually .6C is considered ideal for lithiums.
> 
> It will work at a lower charge rate but you may or may not have a problem with the charge terminating. So you will have to monitor the battery and see if it terminates properly.



Thank you so much for your help. I’m using lithium ion batteries; 26650, 4000mAh. I’m guessing then that the total capacity of the battery (3 cells) is around 12000mAh. Assuming 0.6C (I haven't checked the datasheet yet), does that mean a charging current of 7200mA would be ideal?


----------



## bhsimon (Jun 3, 2013)

hiuintahs said:


> Since your cells are in parallel, they will just look like one cell with triple the current capacity. So that means it will take 3 times as long to charge with one board at a fixed charging current.
> 
> You could wire a charger to each cell but then you'd have to disconnect each of the cells in the pack so that the individual charging boards do not fight each other. That sort of defeats your purpose of not being able to disassemble when charging.
> 
> Hope that helps.



I read up thread that the chargers can be wired in parallel, though I’m not sure I really understand how that works, even though I’ve studied mvyrmnd’s pictures closely. Does that mean, for instance, that I can wire the (+) output terminal of one charger to the (+) output terminal of the next charger and then to the (+) parallel battery wire? Will this give me a greater input charge current?

Once again, I’m sorry for my ignorance and are very grateful to you and Knight_Light for taking the time to help me.


----------



## Knight_Light (Jun 4, 2013)

bhsimon said:


> Thank you so much for your help. I’m using lithium ion batteries; 26650, 4000mAh. I’m guessing then that the total capacity of the battery (3 cells) is around 12000mAh. Assuming 0.6C (I haven't checked the datasheet yet), does that mean a charging current of 7200mA would be ideal?


You would have to check the datasheet but so far you got the hang of it. You can also look at C in terms of time value. In other words how long do you have to charge the batteries? Do you need them charged to full capacity or is 90% capacity satisfactory? Based on your criteria for your pack and the information in the datasheet you can create a charging solution for yourself. Just remember all things being within reason the slower you charge the easier it is on your batteries and the longer they will last.

So if I needed to charge my batteries really fast I would use a higher current and charge to 90% capacity. If I had time to spare I would create a charge cycle that would be closer to 4 to 5 hours in length and charging to full capacity.


----------



## Knight_Light (Jun 4, 2013)

bhsimon said:


> I read up thread that the chargers can be wired in parallel, though I’m not sure I really understand how that works, even though I’ve studied mvyrmnd’s pictures closely. Does that mean, for instance, that I can wire the (+) output terminal of one charger to the (+) output terminal of the next charger and then to the (+) parallel battery wire? Will this give me a greater input charge current?
> 
> Once again, I’m sorry for my ignorance and are very grateful to you and Knight_Light for taking the time to help me.


 Wiring chargers together in parallel is something that I cannot help you with. I am sorry.


----------



## mvyrmnd (Jun 4, 2013)

bhsimon said:


> I read up thread that the chargers can be wired in parallel, though I’m not sure I really understand how that works, even though I’ve studied mvyrmnd’s pictures closely. Does that mean, for instance, that I can wire the (+) output terminal of one charger to the (+) output terminal of the next charger and then to the (+) parallel battery wire? Will this give me a greater input charge current?
> 
> Once again, I’m sorry for my ignorance and are very grateful to you and Knight_Light for taking the time to help me.



Thats's pretty much it.

I have both my batteries and chargers all hooked up in parallel. When I'm charging my 32650's I'm effectively getting a 2A charge applied to a giant 12Ah battery.


----------



## RoGuE_StreaK (Jun 4, 2013)

Put a tap to the + of each battery, and make a 3S1P setup; put a charger across each of the taps. Look into RC plane/heli batts and chargers to see how they do it, this way each battery is charged/balanced individually while still in a serial config. Treating them as one parallel entity is a good way for things to go  if the cells get out of balance.
Do an image search for 3s1p and hopefully it'll clear things up.


```
|--   +{CHRG}-   --|--   +{CHRG}-   --|--   +{CHRG}-   --|
|                         |                         |                         |
|--   +{BATT}-   --|--   +{BATT}-   --|--   +{BATT}-   --|
```

The cheaper chargers use a single charge/balance circuit and cycle through the three taps; takes longer, but is a lot cheaper and works well.


----------



## Knight_Light (Jun 4, 2013)

mvyrmnd said:


> I have both my batteries and chargers all hooked up in parallel. When I'm charging my 32650's I'm effectively getting a 2A charge applied to a giant 12Ah battery.


May I ask why you utilize such a low charge current (.17C)?


----------



## mvyrmnd (Jun 4, 2013)

Knight_Light said:


> May I ask why you utilize such a low charge current (.17C)?



I'm not in a hurry, plus wiring up more chargers is a PITA


----------



## bhsimon (Jun 5, 2013)

mvyrmnd said:


> Thats's pretty much it.
> 
> I have both my batteries and chargers all hooked up in parallel. When I'm charging my 32650's I'm effectively getting a 2A charge applied to a giant 12Ah battery.



My thanks to you and Knight_Light for your invaluable help. Really grateful. I will post some pics of my project when I’m finished.



RoGuE_StreaK said:


> Do an image search for 3s1p and hopefully it'll clear things up.



Thanks for the tip. Will look into it.


----------



## uk_caver (Jun 5, 2013)

RoGuE_StreaK said:


> Put a tap to the + of each battery, and make a 3S1P setup; put a charger across each of the taps. Look into RC plane/heli batts and chargers to see how they do it, this way each battery is charged/balanced individually while still in a serial config. Treating them as one parallel entity is a good way for things to go  if the cells get out of balance.


Wasn't he wishing to _use_ the cells in a 3p configuration?
Assuming that the cells were not so far out of balance when first connected that excessive currents flowed until they were in balance, what is the issue with having them in parallel - how can they get out of balance later on when they are in parallel?


----------



## RoGuE_StreaK (Jun 5, 2013)

uk_caver said:


> Wasn't he wishing to _use_ the cells in a 3p configuration?


Sorry, seem to have misread what he was asking...


----------



## Knight_Light (Jun 5, 2013)

mvyrmnd said:


> I'm not in a hurry, plus wiring up more chargers is a PITA


 Can I ask what kind of charger do you have that the charge current is limited to 2 A?


----------



## mvyrmnd (Jun 5, 2013)

I'm just using a 5V 2A wall wart from some dead ADSL modem. I could get sometrhing more powerful, but this charger was built from two of the board the thread is about, and scrap parts. It's still my best 32650 charger, even if it is a bit slow


----------



## Knight_Light (Jun 6, 2013)

mvyrmnd said:


> I'm just using a 5V 2A wall wart from some dead ADSL modem. I could get sometrhing more powerful, but this charger was built from two of the board the thread is about, and scrap parts. It's still my best 32650 charger, even if it is a bit slow


 Hey if it works for you and you are happy with it that is all that matters.


----------



## bhsimon (Jun 26, 2013)

bhsimon said:


> I read up thread that the chargers can be wired in parallel ... Will this give me a greater input charge current?



I’ve now received my chargers. A group of 5 from eBay and a single unit from DX. These are the single TP4056 chip variations; I’m still waiting on another batch of the 1.5A two-chip variants from a different seller on eBay. I’ll report on those when I receive them.

Using a 3A power supply I can charge a 25500 cell (3500mAh) in about 4 hours, using a single charger. I’m just about to fully discharge the battery (it is protected) and then wire up two chargers in parallel. This will give me a charging current which is closer to 0.5C. I’ll report on how long the charging takes with this configuration and then I’ll consider wiring up a third (and maybe fourth) charger in parallel to see how the charging time is reduced.

Both of the boards I have tested so far will terminate at 4.17V. I’ve read conflicting details on what that means in terms of capacity. How much of the overall capacity is in that final 0.03V? Is it 3%? 5%? It’s a bit of a slow process, but I’m searching through my batch of six chargers to find one which will charge to the full 4.2V and I will be sure to include that one as part of the group in the parallel setup.


----------



## mvyrmnd (Jun 26, 2013)

bhsimon said:


> Both of the boards I have tested so far will terminate at 4.17V. I’ve read conflicting details on what that means in terms of capacity. How much of the overall capacity is in that final 0.03V? Is it 3%? 5%? It’s a bit of a slow process, but I’m searching through my batch of six chargers to find one which will charge to the full 4.2V and I will be sure to include that one as part of the group in the parallel setup.



The final cutoff is a function of the internal resistance of the battery. If the chargers are working properly, with a proper CC/CV charge algorithm, then they should all cut off at the same voltage. Driving a cell to 4.2V at any cost is a BadThing™

The charger, in the CV stage, will cut off once it senses the charge rate has dropped below a given current. I'm not sure what that value is for these.

As far as a loss in useable capacity - reports will vary, but it's in the ball park of "Bugger All" and "A Bees Knob"


----------



## bhsimon (Jun 26, 2013)

mvyrmnd said:


> The final cutoff is a function of the internal resistance of the battery. If the chargers are working properly, with a proper CC/CV charge algorithm, then they should all cut off at the same voltage. Driving a cell to 4.2V at any cost is a BadThing™
> 
> The charger, in the CV stage, will cut off once it senses the charge rate has dropped below a given current. I'm not sure what that value is for these.
> 
> As far as a loss in useable capacity - reports will vary, but it's in the ball park of "Bugger All" and "A Bees Knob"



Thank you, mvyrmnd. I didn’t know this. Very grateful for the help.


----------



## bhsimon (Jun 27, 2013)

mvyrmnd said:


> The final cutoff is a function of the internal resistance of the battery. If the chargers are working properly, with a proper CC/CV charge algorithm, then they should all cut off at the same voltage. Driving a cell to 4.2V at any cost is a BadThing™
> 
> The charger, in the CV stage, will cut off once it senses the charge rate has dropped below a given current. I'm not sure what that value is for these.
> 
> As far as a loss in useable capacity - reports will vary, but it's in the ball park of "Bugger All" and "A Bees Knob"



FWIW, there is definitely a difference in cutoff voltage between different chargers on the same cells. With a battery of two cells wired in parallel and two chargers wired in parallel, one of them finishes charging before the other. The same behaviour can be observed using the two chargers individually on the same battery pack. One will cutoff at 4.17V and the other at 4.2V.


----------



## HKJ (Jun 27, 2013)

bhsimon said:


> FWIW, there is definitely a difference in cutoff voltage between different chargers on the same cells. With a battery of two cells wired in parallel and two chargers wired in parallel, one of them finishes charging before the other. The same behaviour can be observed using the two chargers individually on the same battery pack. One will cutoff at 4.17V and the other at 4.2V.



Be careful with what you call voltages.
cutoff voltage is at what voltage the charger stops charging, this is the same voltage used during the CV phase (Due to resistance in the circuit this the CV voltage can be slightly lower).
battery resting voltage is the voltage you can measure on the battery, when you take it out of the charger (or in the charger, after it has stopped charging). 

The resting voltage will depend on both the cutoff voltage and the cutoff current and a lot of parameters of the actual battery. I.e. using a cutoff voltage of 4.200 volt can easily give a resting voltage between 4.112 volt and 4.192 volt on the same battery, depending on termination current and time before the measurement is done. The 4.192 volt was measured after 10 second with a 50mA cutoff current, the 4.192 volt was measured after one hour with a 400mA termination current.

All chargers does also have a tolerance on both cutoff voltage and cutoff current, i.e. even two copies of the same charger or two channels on a multichannel charger will not leave the batteries at exactly the same resting voltage. The TP4056 does have rather wide tolerances on the cutoff voltage: 4.137 to 4.263 volt.


----------



## RoGuE_StreaK (Jun 27, 2013)

Been a while since I looked at these, just did a new search for TP4056 on ebay and noticed that most of the boards now have a temperature pad; anyone got any info on how to utilise this? I know most mobile phone batteries have three terminals, the middle being a temp sensor; is the temp port actually being usable on these boards, if so what does it do, and what cheap sensor can be used to interface with it?


----------



## bhsimon (Aug 2, 2013)

I just want to reiterate what was said upthread about minor inconsistencies between boards from the same batch, in case anyone visits this page in the future. They may find this to be useful information.

When I purchased my boards they were in a row of 5, unbroken. They break apart easily.

In my batch there are have been definite inconsistencies in the cutoff voltage between one board and the next. Some will terminate charging below 4.2V.

I realise HJK was trying to explain something upthread, but I'm referring to a specific characteristic and I can confirm that there are minor differences.

One of the boards in particular performs flawlessly every time and I can measure exactly 4.2V at the moment the light turns green to signify that charging is complete. Other boards will leave the same cell at lower voltages; some as low as 4.10V. Indeed, this same characteristic can be observed with multiple cells of different sizes. The same boards will behave the same; that is, they are consistently stopping charging before 4.2V.

I don't see this as a major issue, but if you are concerned about such things it might be worth buying 5 pieces and testing each one to get the best out of the group. They aren't expensive. I've created a charging ‘block’ out of 4 of them wired in parallel and I use it on large 26500 and 26650 cells.


----------



## light-wolff (Aug 2, 2013)

HKJ said:


> The TP4056 does have rather wide tolerances on the cutoff voltage: 4.137 to 4.263 volt.


Yes, and they tend to utize the full tolerance range.

I've had 12 TP4056 boards from 4 different sellers.
I measured CV voltage (measured at termination current) to sort out the bad ones and keep the good ones: it ranged from 4.125 to 4.265V. Im now using the 3 best ones, programmed to 100, 250, 500mA charging current, as "reference" chargers for battery testing: 4.197, 4.201, 4.203V.

There seem to be different TP4056: termination current ranges from 0.1 to 0.15Ic, und their behaviour when termination current is approached is also different.
Once I purchead 5 at once, and all of them were at or slightly beyond the boundaries of the tolerance range. None of them was close to the center.
I tend to believe these ultra cheap charger boards are sometimes made with B grade ICs that were rejected for not meeting specs. Or even with cheap IC copies.


----------



## Kenjutsu (Aug 16, 2013)

Hello everyone,

These chargers seems to be just awesome. :thumbsup: Is there a specify eBay seller you would recommend that ships internationally? Also, has anyone come across such a charger board that can also charge LiFePO4 batteries, and one that can charge only NiMh batteries?

Thank you,


----------



## litos (Jan 11, 2014)

I'm planning on making a pack with 4 18650 in series, to convert the battery of an old cordless NiCad drill to Lithium. I wanted to use 4 of these boards to charge the batteries, one for each, to charge them individually while connected in series, with the series circuit open. Then all the boards will be connected to a power supply of 5V 4A. 
Can it be done like this? Here's the scheme:


----------



## HKJ (Jan 11, 2014)

litos said:


> I'm planning on making a pack with 4 18650 in series, to convert the battery of an old cordless NiCad drill to Lithium. I wanted to use 4 of these boards to charge the batteries, one for each, to charge them individually while connected in series, with the series circuit open. Then all the boards will be connected to a power supply of 5V 4A.
> Can it be done like this? Here's the scheme:



No, that would short most of the batteries.
You need four isolated power supplied.


----------



## litos (Jan 11, 2014)

Do you mean like this?






With all power supply connected to mains, won't I have the same problem?


----------



## HKJ (Jan 11, 2014)

litos said:


> Do you mean like this?
> 
> 
> 
> ...



Exactly. The power supplies has isolation between mains and low volt side, preventing any problem.

The charge module has direct DC connection, usual the battery minus terminal is directly connected to the power input minus terminal, i.e. when you connect all the charger module to the same power supply, all the battery minus terminals are shorted together.


----------



## litos (Jan 11, 2014)

That's not gonna be possible. I don't have space for all those power supplies inside the pack, plus the boards. Also I don't want to bring out lots of wires.


Maybe I could use one of these: Ebay item: 251403347508


I don't know if this works as charger (making cc/cv) or just as protection. If this works as charger, then it's pretty much straightforward. If it's just protection then i can use one of these to power the other boards somehow?


----------



## HKJ (Jan 11, 2014)

litos said:


> That's not gonna be possible. I don't have space for all those power supplies inside the pack, plus the boards. Also I don't want to bring out lots of wires.
> 
> 
> Maybe I could use one of these: Ebay item: 251403347508
> ...



It looks like it is only protection.
It can be used, but you will probably need to balance the cells in another charger once in a while.
You also need a 4S LiIon charger, i.e. a CC/CV charger with 16.8 volt output.


----------



## uk_caver (Jan 11, 2014)

Presumably a hobby charger is the easiest solution.

Having lots of wires hanging out of the pack would be ugly and/or inconvenient, but possibly a small socket (like the ones hobby chargers use for balance leads) could be fitted into the shell of the pack somewhere, and a suitable plug-to-plug lead made up?


----------



## litos (Jan 11, 2014)

I guess I'll use the second solution. 
I'll put the 4 boards and power supplies inside the modified charger box, and use a 5 pin din connector to connect them all to the batteries.


----------



## Squashie (May 29, 2014)

Please help

Not sure if i am able to post a website link so i am rewriting the post.

Sparkfun website sells batteries. I need to know what resistor should i put to charge the 400 mah li-po the 850 and the 1000 mah. Also what is the current at which they should be charged?


Thanks.


----------



## RoGuE_StreaK (May 29, 2014)

Squashie said:


> I need to know what resistor should i put to charge the 400 mah li-po the 850 and the 1000 mah. Also what is the current at which they should be charged?


There are datasheets for those batteries on the Sparkfun site; for example, the 400mAh says a standard charge of 0.2C (50mA), fast charge of 1C (250mA). Actually those figures don't seem to match, 0.2C should be 80mA in this case, 1C 400mA, but I'd go with the specified current rather than the stated C rating.

Resistors (from datasheet):
10k for 130mA, 5k for 250mA, 4k for 300mA, 3k for 400mA, 2k for 580mA, 1.66k for 690mA, 1.5k for 780mA, 1.33k for 900mA, 1.2k for 1000mA


----------



## Squashie (May 29, 2014)

Thanks but where on the battery data sheet do you see this info?


----------



## RoGuE_StreaK (May 29, 2014)

For the 400mAh (product #10718), the linked "li-po cell" datasheet, No.6 (Charging Method) under Electrical Characteristics

PS. I only checked the 400mAh


----------



## Squashie (May 30, 2014)

Perfect. Thank you very much.

so you could basically charge it anywhere from 50 tp 250 and be fine (based on the sheet) and 80 to 400 based on common knowlage


----------



## rizky_p (Nov 3, 2014)

Well this is an old thread, i just build a glorified tp4056 charger using a dead 18650 charger as a host.

https://www.youtube.com/watch?v=pfeUvWDY5_E

hope you guys like it, not pretty lol i just slap all of them with hot glue. I intent to use a 0.96in OLED display but the hitachi 16x2 character display arrived first and i couldn't be bother to swap it as the OLED display is currently on another project.


----------



## Kenjutsu (Nov 5, 2014)

*@rizky_p*: Do you use the Arduino and the LiPo gauge just to monitor the charging process and give feedback on the LCD?


----------



## alltoclear (Nov 9, 2014)

Hi guys, any idea how we could mod this board's full charge voltage to 4.35v so that i could use it to charge a Lg D1 cell?


----------



## Illum (Nov 9, 2014)

Probably not alltoclear

Only charger I know that outputs 4.35V is MCP73831-3


Been using this with nice results.
http://www.adafruit.com/products/1304

The inherent problem with linear chargers... is heat from voltage drops.


----------



## hiuintahs (Nov 10, 2014)

Edit: post deleted


----------



## Bullzeyebill (Nov 11, 2014)

hiuintahs said:


> If I thought it was worth the investment, then I'd market my chargers (I've got 2 designs.....one USB fixed value using the LTC4053 and the other discrete design utilizing a buck regulator with both voltage feedback and current to get the CC/CV charge process. That one has a pot where I can set the termination voltage to whatever I like.



Start your own sales thread when you are ready. Custom mods such as this can be displayed on CPF, not in this thread, but in Custom BST. This as long as you are not a manufacturer, per se.

Bill


----------



## rizky_p (Nov 23, 2014)

Kenjutsu said:


> *@rizky_p*: Do you use the Arduino and the LiPo gauge just to monitor the charging process and give feedback on the LCD?


Sorry for the late reply. Yes i use the max lipo gauge to read the voltage as i have them lying around, or you can just use analog input from one of the arduino pin and some voltage devider. The max chip communicates through IIC interface with the arduino. In recent changes i also add current monitoring using alegro hall sensor and report the current back to lcd.


----------



## Matthew86 (Nov 24, 2014)

Hi,

I'm using a DX version of this board. The problem is its termination appears to be at <50ma and at 4.25v or so.
I've tried a 0.5ohm resistor in series when charging and that seems to drop the termination voltage to safer levels.

The question is whether that's a safe modification and whether it could create issues in the constant current phase of charging?


----------



## BringerOfLight (Nov 24, 2014)

Matthew86 said:


> Hi,
> 
> I'm using a DX version of this board. The problem is its termination appears to be at <50ma and at 4.25v or so.
> I've tried a 0.5ohm resistor in series when charging and that seems to drop the termination voltage to safer levels.


4.25V is still safe, but not good for battery lifetime.


> The question is whether that's a safe modification and whether it could create issues in the constant current phase of charging?


Yes, it's safe to do. The TP4056 will normally terminate at C/10, so you have a 500mA board, right?

At 500mA, your 0.5Ohm resistor will drop 0.25V. So if the TP4056 targets 4.25V, it will already ramp down the charge current (enter the CV phase) at 4V battery voltage. The charge time will be a fair bit longer.

4.25V is well within the TP4056 specs (4.137V - 4.263V). You may want to play the chip lottery and get a 5 or 10-pack of those boards. I have one that charges to 4.165V.


----------



## RoGuE_StreaK (Nov 24, 2014)

I think I recall some fake or "alternate" chips out there, which may or may not be part of what you are seeing. I've just tried a quick search and can't find anything to back this up, so not sure what the situation was.


----------



## Matthew86 (Nov 25, 2014)

BringerOfLight said:


> ...The TP4056 will normally terminate at C/10, so you have a 500mA board, right?
> 
> At 500mA, your 0.5Ohm resistor will drop 0.25V. So if the TP4056 targets 4.25V, it will already ramp down the charge current (enter the CV phase) at 4V battery voltage. The charge time will be a fair bit longer...



Yeah I noticed that. Its a bit of a pain but Ive been switching to the resistor after the voltage hits 4.2. 
Its a 1amp board but I found out the apple USB source has only been outputting 0.5amp, strangely today it looked like ~0.1amp termination.:thinking:



BringerOfLight said:


> ...4.25V is well within the TP4056 specs (4.137V - 4.263V). You may want to play the chip lottery and get a 5 or 10-pack of those boards. I have one that charges to 4.165V.



That is the plan I think. 
Cheers


----------



## tomasi02 (Dec 24, 2014)

Home made charger:

1.






2.





Is the wiring for #2 ok?
Sometimes led is not on on the second slot, when charging only one battery.


----------



## Illum (Feb 20, 2015)

Can anyone confirm that the battery output pins are high impedance when the battery is connected but input supply turned off?
My charger boards should be arriving soon and I plan on integrating them into systems involving a permanently connected battery


----------



## thijsco19 (Apr 8, 2015)

If I leave this TP4056 based charger board connected to a Li-ion/Li-Po cell, without input power, will it drain the cell? 
If yes, how quick?
(I believe my question is similar to Illum's question..?)

Oh, this charger works for both Li-ion cells and Li-Po cells, right?
NVM the last question, I don't see reasons why it wouldn't work with Li-Po type cells.


----------



## HKJ (Apr 8, 2015)

thijsco19 said:


> If I leave this TP4056 based charger board connected to a Li-ion/Li-Po cell, without input power, will it drain the cell?
> If yes, how quick?



The one I tested had a current draw of about 1uA, that will drain a battery in 40 years.


----------



## thijsco19 (Apr 8, 2015)

Thanks!
That is what I was hoping to hear. Add a protection pcb to it and it should be relatively safe.


----------



## CuriousOne (Apr 9, 2015)

The real gem for linear battery chargers it Linear's LTC1185 chip:

1. It is big, in TO-220 case, so no special soldering skills required, actually, you can just wind wires across it's legs.
2. It requires very few external componens.
3. You can set individually both charging voltage and current (up to 3A).
4. It has low drop circuitry, so even from USB 5V you can charge 4.35V cells at high currents.

It has two drawbacks:

1. Since this is LDO, not charger IC, it has no charge completion indication.
2. Quite expensive- around $9

I've built more than 10 chargers with it, all work just fine.


----------

