# Samsung 3000 mAh 18650 Testing



## SilverFox (May 12, 2010)

Jasonck08 sent me one of these cells to check out. Over the past 2 months I have been running it through a series of tests and have found that it is a very good cell.

Let's get into the details...

The cell came with a protection circuit, so I charged it up and ran some tests on it. As you can see, the protection circuit tripped during the 4 amp discharge.

Capacity was lower than the labeled 3000 mAh (it actually came in at 2496 when discharged at 0.5 amps), but more on this later.

Here is the graph of this protected cell.







The specification for these cells calls for charging to 4.35 volts, and the 3000 mAh capacity is rated at a 0.2 amp discharge rate with the cell being discharged down to 2.75 volts.

Following the specification, I ended up with 2999 mAh. Wow, not bad.

At 4 amps, I noticed the cell was warming up, and it got hot during the 6 amp discharge. It would probably not be a good idea to continually discharge at 6 amps or above, although the cell would probably handle it a few times.

I stopped my testing at 6 amps because I wanted to determine if the cell could really handle being charged to 4.35 volts without damage to the cell.

Here is the graph of the bare cell.






After this testing was complete, I then ran the cell through 20 charge/discharge cycles charging at 3 amps to 4.35 volts, and discharging at 3 amps to 2.75 volts. At the end of this cycling, I ran another discharge at 0.2 amps, and it came out to the same as the first discharge at 0.2 amps, so no damage was done. 

I then charged the cell up to 4.35 volts and let it sit on the shelf fully charged for 2 weeks. The discharge at 0.2 amps showed only a very slight change in capacity but not enough to indicate much damage.

At 6 amps of discharge the midpoint voltage was about 3.3 volts. It is nice if a Li-Ion cell can maintain a midpoint voltage of 3.5 volts, but at higher loads, the voltage drops off. The discharge rate for this cell holding a midpoint voltage of 3.5 volts was 4 amps. The mid point voltage during the 0.2 amp discharge was 3.85 volts.

These cells give you about 84% of labeled capacity when charged to 4.2 volts, which should greatly extend their cycle life, or full capacity if you have the ability to charge to 4.35 volts. You will have to contact Jason to figure out how to get a hold of some of these cells. The protection circuit adds some size to the cell. The bare cell is a typical 18650 cell. Jason has the details on the protection circuit, but it would be ideal if it could be set for a discharge rate of 6 amps.

All in all this is a strong cell. I am not sure what the advertised cycle life is, but I put over 50 cycles on it and there is very little change in capacity. I may have to try some higher discharge rates to see where things begin to break down, but on the other hand I may just use the cell in one of my lights...

Tom


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## paulr (May 12, 2010)

I wonder how to charge a cell to 4.35 volts without special equipment--most li ion chargers, including programmable hobby chargers that I know of, are preset to 4.2 volts. Maybe some fancy ones allow adjusting this, but for example my Triton doesn't and I doubt if AW-style drop-in chargers do.


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## Mr Happy (May 12, 2010)

paulr said:


> I wonder how to charge a cell to 4.35 volts without special equipment--most li ion chargers, including programmable hobby chargers that I know of, are preset to 4.2 volts. Maybe some fancy ones allow adjusting this, but for example my Triton doesn't and I doubt if AW-style drop-in chargers do.


A bench power supply could do this. For some this could count as special equipment, but for the really dedicated hobbyist it might be a standard item...


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## AW (May 12, 2010)

I have been testing similar chemistry cells for the past few months and it just looked like Samsung has taken an aggressive step to raise the charging voltage from 4.30V from 4.35V in order to increase the holding capacity by a few percentage points. The Samsung 2800mAH cell and similar Sanyo UR18650ZT cells both have a charging voltage of 4.30V as well. These are still LiCo based cells even though another element has been added in the formulation to increase the capacity and the electrolyte will break down @4.5V emitting heat and gas. The biggest draw back is the requirement of a different charger with a higher ending voltage of 4.35V and the associated danger of unsuspecting users charging regular 4.2V cells in it. BTW, these type of cells are designed to make packs with an optimal 1C discharge.


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## paulr (May 13, 2010)

Mr Happy said:


> A bench power supply could do this. For some this could count as special equipment, but for the really dedicated hobbyist it might be a standard item...



Well there's more to it than that, you are supposed to charge at constant current til the cell reaches a certain voltage, then switch to constant voltage charging til the current drops to a certain level, then stop charging, preferably while monitoring temperature all along. IOW you want a charger, not a bench supply, unless you want to sit in front of it monitoring progress and switching settings at just the right moment.


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## HKJ (May 13, 2010)

paulr said:


> Well there's more to it than that, you are supposed to charge at constant current til the cell reaches a certain voltage, then switch to constant voltage charging til the current drops to a certain level, then stop charging, preferably while monitoring temperature all along. IOW you want a charger, not a bench supply, unless you want to sit in front of it monitoring progress and switching settings at just the right moment.



A good bench power supply has no problem doing the CC/CV charge. It is only the shut off at the end of charge that is missing and that does not have to be very precise.


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## Milan (May 13, 2010)

We might finally have a use for overcharging Trustfire TR-001 charger. Just let it sit in the charger for a day and (watch the fire  ) - and 4.3 reached. No really, it's safe using the 12V side plug.
But something tells me that people using these hi-tech cells don't use cheap chinese chargers.


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## zelda (May 13, 2010)

I couple of month ago, I saw graphs from 2800 to 3000mAh cells. From 1A and higher discharge rate, the capacity fall quickly. --> A 2400mAh cell did a better job.

This Samsung cells hold the capacity considerably better at higher rate.

Some $$$ hobby-charger have a "free slot" for programming special batteries.
I use a Futaba cdr5000 Ni-Mh charger in manuall mode, can charge any chemistry with CC/CV in 0.001V & 0.001A increments with a couple of shutdown options.

zelda


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## jirik_cz (May 13, 2010)

I purchased Samsung ICR18650 2800mAh cells six months ago and finally have a charger that can eventually "overcharge" up to 4.3V (soshine SC-S1 V2). I can confirm, that when charged to ~4.2V these cells have only around 2500mAh. But when charged up to 4.3V they are pretty good. 

mWh are comparable to Panasonic NCR18650 2900mAh cells. The PTC kicks in at 10A discharge.


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## dan1million (May 13, 2010)

Excellent test work Silver fox well done - thanks for the info

-Dan


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## 45/70 (May 13, 2010)

SilverFox said:


> The cell came with a protection circuit, so I charged it up and ran some tests on it. As you can see, the protection circuit tripped during the 4 amp discharge.



I'm assuming this protection circuit was added on, and not provided by Samsung, correct? If it was provided by Samsung, it would be the first instance of a Li-Ion cell manufacturer offering a Li-Ion cell with a protection circuit, that I'm aware of.

Dave


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## SilverFox (May 13, 2010)

Hello Dave,

Correct. The protection circuit was added on by others and not by Samsung.

Tom


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## jasonck08 (May 13, 2010)

Thanks for the post Tom. And its good to see that its a solid cell.

As stated above, its probably not that ideal for most people because of the increased charging voltage of 4.35v (requireing a special charger).

One advantage though is if one bought this cell and only charged it up to 4.20-4.25 (what most cheaper charger charge to) the cycle life may be significantly increased.

Instead of getting 300-400 cycles, one might get 500-600 @ 4.2v cutoff.


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## Bapman (May 28, 2010)

Hello Tom,

I'm a newbie.

Do you think that this spec of charging to 4.35v is the next
evolutionary step for Li-Ion batteries,with more cell manufacturer going 
toward this direction?

For the 4.20v Li-Ion ,2600mah(18650) will be the maximum (real) capacity?

Thanks.

Ben.


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## Bullzeyebill (May 28, 2010)

I'm thinking that the newer high cap Li-Ions that can charge to 4.35 will have to have had some internal changes to chemistry/construction of the cells. 

Bill


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## Fallingwater (May 29, 2010)

paulr said:


> Well there's more to it than that, you are supposed to charge at constant current til the cell reaches a certain voltage, then switch to constant voltage charging til the current drops to a certain level, then stop charging, preferably while monitoring temperature all along. IOW you want a charger, not a bench supply, unless you want to sit in front of it monitoring progress and switching settings at just the right moment.


What's the big deal? Set voltage to 4.2 (or 4.35V in this case), set current to what you want to use for the CC part, connect cell and it'll do everything automatically.



Mr Happy said:


> A bench power supply could do this. For some this could count as special equipment, but for the really dedicated hobbyist it might be a standard item...


And then there are those of us with two of them, stacked one on top of the other.


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## SilverFox (May 30, 2010)

Hello Ben,

Welcome to CPF.

I think that the 4.35 volt cells will be used in special applications. If we can get decent cycle life charging to 4.35 volts, and get an additional 12% out of the same sized package, this will result in longer run time. The charging system on a computer, for example, can be modified to charge to 4.35 volts without too much effort and cost. 

If this chemistry mix is stable, then others may also choose to do something similar. I don't have all the details on this chemistry, so I really don't know.

I think that Li-Ion 18650 cells will settle out at around 2600 mAh of capacity, but I have been wrong before. I don't think the manufacturers can cram more material into the cells, so improvements will have to come by changes in chemistry. 

Tom


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## jasonck08 (May 30, 2010)

I remember reading and seeing that they think they can cram like 3500-4000mAH into a 18650 in the next couple of years...

Also because the voltage of these newer cells is higher, we have to keep in mind that the energy density is more then just 2600 vs 3000mAH. The Samsung should have a higher voltage throughout the discharge curve then most traditional 4.2v LiCo cells.

Panasonic has a 3100mAH 18650, but it has not been mass produced yet.

Tom, have you done much testing yet on the Sanyo 2600's I sent you??


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## klorsey (Jul 30, 2010)

Are these Samsung 3000 mAh cells available online?I've never come across them.


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## klorsey (Aug 1, 2010)

Hi all,what do you think would be a good bench power supply for charging things like these Samsung 3000mAh 1850's (to 4.35v) as well as:

NiMH: AAA,AA,C,D and 9 volt batteries.

Lithium-ion+Lipo's: 18650's and similar for use in torches,9 volt Lithium-polymer's.

I'm interested in the cheapest bench power supply that could do these jobs properly and safely.

Any advice appreciated.klorsey


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## jasonck08 (Aug 1, 2010)

The problem with a bench power supply, is you will not be able to follow the recommend CC/CV Charging algorithm that most li-ion manufactures recommend.
 
For these cells specifically, I'd recommend first charging them via an RC (hobby charger) such as the Turnigy Accucel-6.
 
Then top them off with a bench / lab power supply at a regulated 4.35v @ <100mA.


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## Whitedog1 (Aug 2, 2010)

jirik_cz said:


> I purchased Samsung ICR18650 2800mAh cells six months ago and finally have a charger that can eventually "overcharge" up to 4.3V (soshine SC-S1 V2). I can confirm, that when charged to ~4.2V these cells have only around 2500mAh. But when charged up to 4.3V they are pretty good.
> 
> mWh are comparable to Panasonic NCR18650 2900mAh cells. The PTC kicks in at 10A discharge.


 
Panasonic 2900mAh: 4.2v charge termination
Samsung 2800mAh: 4.3v charge termination

So, actually the Panasonic 2900mAh cell is the best choice for end consumers because it can be charged in any lion charger with 4.2v shutoff and you will get the full capacity??:candle:


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## Lion251 (Aug 2, 2010)

jasonck08 said:


> The problem with a bench power supply, is you will not be able to follow the recommend CC/CV Charging algorithm that most li-ion manufactures recommend.


If you have a bench power supply where you can set both current and voltage, then it will follow the CC/CV algorithm perfectly.
Current will be limited until the set voltage is reached, then voltage will be kept constant.
The only thing you will be missing is the total switch-off of current when it has dropped to a few percent of maximum, so you cannot let the batteries be connected for extended periods of time.
And, with a bench power supply, you can charge only one cell at a time.
Otherwise, I don't see any problems.


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## 45/70 (Aug 2, 2010)

jasonck08 said:


> The problem with a bench power supply, is you will not be able to follow the recommend CC/CV Charging algorithm that most li-ion manufactures recommend.



Sure you can!



Lion251 said:


> ......with a bench power supply, you can charge only one cell at a time......



Unless you charge cells in parallel. 

Dave


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## jirik_cz (Aug 2, 2010)

Whitedog1 said:


> So, actually the Panasonic 2900mAh cell is the best choice for end consumers because it can be charged in any lion charger with 4.2v shutoff and you will get the full capacity??:candle:



Yes.


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## Whitedog1 (Aug 2, 2010)

jirik_cz said:


> Yes.


 
Thanks lovecpf


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## jasonck08 (Aug 2, 2010)

Lion251 said:


> If you have a bench power supply where you can set both current and voltage, then it will follow the CC/CV algorithm perfectly.
> Current will be limited until the set voltage is reached, then voltage will be kept constant.
> The only thing you will be missing is the total switch-off of current when it has dropped to a few percent of maximum, so you cannot let the batteries be connected for extended periods of time.
> And, with a bench power supply, you can charge only one cell at a time.
> Otherwise, I don't see any problems.


 
How would you sent a bench power supply to behave like a hobby charger?

Most proper Li-ion chargers start off at a high current (say 1A for a 18650) then they slow down to <100mA once the voltage reaches about 4.1v and do the CC/CV stage.

I don't see how this is possible on a bench power supply?

Sure you could set the charger to 100mA @ 4.2v and let it charge for over a day, but that wouldn't be practical.



45/70 said:


> Sure you can!
> 
> 
> 
> ...


 
How can you realistically charge a 18650 cell on a bench power supply in a reasonable amount of time?


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## 45/70 (Aug 2, 2010)

jasonck08 said:


> How can you realistically charge a 18650 cell on a bench power supply in a reasonable amount of time?



It's pretty easy really. I used to do it quite a bit, especially for LiFe cells.

The PS in my old Metex MS-9140 is a "no frills" non-programmable PS, so everything has to be done manually. It simply has voltage and current control. So, say I want to charge a 1000mAh LiCo cell at a 0.5C rate, CC/CV. I set the PS up with the voltage set at 30 Volts and the current to zero. I hook up the cell and adjust the current up to 500mA. The cell begins to charge at a constant 500mA rate (CC). When the circuit (not the cell) voltage reaches 4.20 Volts, I then limit the voltage to 4.20 Volts (CV). When the current eventually drops down to 15mA (0.03C), I stop the charge.

Where I'm guessing a lot of people go wrong here using a simple type PS, is they initially set the voltage to 4.20, and the current to 500mA (in this example). This is really a "CV only" charge scenario, and not really CC/CV. Also, it will take about forever to do it this way.

And yes, if you don't watch the charge process *very carefully*, you can get into big trouble charging a LiCo cell at 30 Volts!  The fact is though, that unless you are charging A123 cells at a 20C rate, or something, things happen pretty slowly, so provided you keep a close eye on things, it can be done safely. It's still a PITA compared to using a proper charger though. A programmable PS would be a big help in this regard. 

I might add that this method is not for everybody. I don't suggest that folks go out and buy a bench PS to charge their Li-Ion cells. In addition to potential safety concerns with a PS like mine, it'd be a whole lot cheaper to just buy a hobby charger, or some other type charger that uses a proper CC/CV algorithm.

Dave


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## jtsgalaxy (Aug 2, 2010)

Another thing to be aware of is most cheapo lab power supply will have voltage draft over time and tempurature also. Frequently check the voltage across the battery using DMM during charge is important too.


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## shadowjk (Aug 2, 2010)

Um, if you don't limit the voltage to 4.2V wont it exceed 4.2 until you come and turn down the voltage limit?

I thought the whole idea of CC/CV was voltage limit @ 4.2V AND a current limiter, and then something to make it terminate when current has dropped to a certain threshold.. You're only missing the termination using a lab PS?


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## 45/70 (Aug 4, 2010)

jtsgalaxy said:


> Another thing to be aware of is most cheapo lab power supply will have voltage draft over time and tempurature also. Frequently check the voltage across the battery using DMM during charge is important too.



Good point about drifting. In addition, most inexpensive PS's don't have all that accurate a display either. For that reason, I use the Metex's DMM for measuring voltage. Although precise accuracy of current measurement isn't really all that critical, I sometimes use a second DMM inline to measure current, as well.

As far as actual cell voltage during charging, this is pretty much irrelevant, as the circuit voltage is what is important, eg. if the circuit voltage is 4.20 Volts, there is no way the cell voltage can be any higher. 



shadowjk said:


> Um, if you don't limit the voltage to 4.2V wont it exceed 4.2 until you come and turn down the voltage limit?



Um, no.  With a discharged cell in the circuit, the circuit voltage will remain below 4.20 Volts, regardless of the OC voltage of the PS during the CC stage. In the previously mentioned example of a 0.5C rate of charge, for example, the voltage will remain below 4.20 Volts for ~1 hour when charging a discharged LiCo cell. It is important to understand that the purpose of the CC stage, is to deliver a *C*onstant *C*urrent through the cell. The only voltage requirement, is that the PS OC voltage be high enough to be capable of supplying the desired charging current.



> I thought the whole idea of CC/CV was voltage limit @ 4.2V AND a current limiter, and then something to make it terminate when current has dropped to a certain threshold..


Yes, the _*circuit voltage*_ is limited to 4.20 Volts. In order to maintain a *C*onstant *C*urrent level during the CC stage however, necessitates that the voltage potential of the PS be higher than 4.20 Volts. Otherwise the current level would diminish throughout the CC stage. This is what occurs during the CV stage. The PS voltage is limited to 4.20 Volts, and as a result, the current gradually diminishes, as the cell approaches a fully charged state.



> You're only missing the termination using a lab PS


More, or less, yes. And again, a programmable PS is much better suited (and safer) for the task.

OK. Waaay OT here. I'll stop. 

Dave


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## shadowjk (Aug 4, 2010)

45/70 said:


> Yes, the _*circuit voltage*_ is limited to 4.20 Volts. In order to maintain a *C*onstant *C*urrent level during the CC stage however, necessitates that the voltage potential of the PS be higher than 4.20 Volts. Otherwise the current level would diminish throughout the CC stage.



It would only diminish if there's extra resistance somewhere in the circuit, or, I dunno, if the power supply lacks proper regulation..

My phone for example has about 120 millOhms of resistance between its charger chip and the battery. At 1200mA charge rate, that's a voltage drop of about 0.144V, meaning the 4.2V output of the charger chip become 4.056V at the battery, making the charge current start tapering off at that battery voltage. But again, that's only because of the extra resistence present on the circuit board..


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## 45/70 (Aug 4, 2010)

shadowjk said:


> It would only diminish if there's extra resistance somewhere in the circuit......



The cell itself is the resistance variable. The more fully charged the cell becomes, the higher it's resistance to charge current.



> ......or, I dunno, if the power supply lacks proper regulation..


You can regulate the current, or you can regulate the voltage, but you can't regulate both. During the CC stage the current is regulated and the voltage increases. During the CV stage the voltage is regulated and the current decreases.

Dave


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## shadowjk (Aug 5, 2010)

The cell's resistance causes the cell's voltage to rise when you charge, but it doesn't cause any taper-off before 4.2V..

OK, how about this:

Set powersupply to 4.2V / 1000mA. Attach some variable load. Observe voltage at different loads. If your voltage actually drops when you increase load, then I can understand you want to fudge it and set the voltage higher during earlier stages of charging...


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## 45/70 (Aug 5, 2010)

OK, it's been so long since I've done it any other way, that I don't actually remember precisely what happens. Mind you, that using a bench PS has never been my primary means of charging any kind of cells, with the exception of NiCd/NiMH battery packs, at a 0.1C rate. Also, I used the PS to charge LiFePO4 cells in parallel for a couple months, as I didn't have a proper LiFe charger for cells larger than 16340's. Presently, I only use the PS for parallel charging NiZn cells. For Li-Ion cells and NiCd/NiMH packs, I use a hobby charger.

That said, from what I can remember, with my PS you cannot preset or adjust the voltage or current with an open circuit. With a cell in the circuit, the voltage can be limited (but of course cannot be set below the present circuit voltage), and current can be adjusted from 0-2A.

With the cell in place, you cannot push current through the cell until the voltage knob is turned up to some point higher than the circuit voltage. This is a "blind" operation, as the voltage reading will still read the circuit voltage. As the voltage knob is turned up, at some point, you will be able to start pushing current through the cell. If you turn the voltage up just enough to allow, say 500mA current flow, as the cell's voltage increases, the current will decrease, and you're basically running CV. Therefore, with this type setup, it's a whole lot easier to just turn the voltage knob up all the way, rather than trying to guess where the "sweet spot" is that would allow 500mA of current to flow until the 4.20 Volt point is reached.

Again, a programmable PS would make this part a whole lot easier to accomplish. And, for me anyway, a hobby charger actually works out better.

My apologies to SilverFox, for taking this thread way off topic.:candle:

Dave


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## Aquanaut (Aug 6, 2010)

Welcome me! This is my first post on Candle Power! I have been lurking here for many days and learned a lot. I am a battery nut so this forum has attracted my attention. Due to posts on this site, I have ordered a Fenix TK11 R5 and a few different chemistry batteries. My background is in chemistry with a minor in electrical engineering. 

My bench power supply operates as follows: first, I short the outputs and set the constant current. Then, without a load I set the desired constant voltage.

When the supply is hooked up to the battery, it supplies a rising current until the set voltage is reached. Then the supply switches over to constant voltage mode and the current reduces at the set voltage.


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## 45/70 (Aug 7, 2010)

Welcome to CPF Aquanaut! :thumbsup:



Aquanaut said:


> My bench power supply operates as follows: first, I short the outputs and set the constant current. Then, without a load I set the desired constant voltage.



Hummm. I had never thought about setting the PS up in this manner. Mind you, I don't have any formal education, or professional background in electronics, it's just a hobby. I did get to try this out however, and it works!

I set up an AW protected 14500 LiCo cell that read 3.80 Volts OC. I set the current at 500mA and the Voltage to 4.20 Volts, in the manner you suggested. I monitored the voltage with the DMM in the Metex (I didn't refer to the PS readout, as it's not very accurate for Volts, or Amps) and ran a Fluke 27/FM inline, to monitor current. Everything progressed just as it should. At ~4.18 Volts the current began to drop. While I stopped the charge early, as this cell is headed back to storage, I can see this is a much better (and safer!) way to use a simple PS to charge Li-Ion cells.



> When the supply is hooked up to the battery, it supplies a _*rising current*_ until the set voltage is reached......


One thing, don't you mean _constant current_ here?

At any rate, Thanks for the information, Aquanaut. I learned something today! Old dogs, new tricks, and so on. 

Dave


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## Aquanaut (Aug 7, 2010)

45/70 said:


> One thing, don't you mean _constant current_ here?



Oops, my bad. I meant: "When the supply is hooked up to the battery, it supplies a _*rising voltage at the set constant current*_ until the set voltage is reached."


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## 45/70 (Aug 9, 2010)

Yeah, I figured.

I haven't attempted to charge anymore Li-Ion cells, as I really have no need to use a PS for this purpose, but did charge a couple NiZn cells using the "new" method. One thing I noticed, is that it would appear that cells take considerably longer to charge now. I wouldn't think that it would make that much difference, but apparently it does. In the case of LiCo cells though, it makes things a lot safer, anyway.

Dave


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## CKOD (Aug 9, 2010)

If it makes anyone feel any better, we charge li-po cells at work with an xantrex dc power supply, when the output is off, it lets you set the current and voltage, and when you turn it on, it displays actual values. 

4.2V/cell and usualy a 1C for current, + to +, - to - and let it sit for ~2-3 hours. Its perfectly fine, no one has died yet, and no puffed up batteries, perfectly fine to do if its being monitored, due to the lack of charge termination, as mentioned.


Oh, and if anyone wants to make your own 500mA or 100mA charger, the maxim max1811 and a 500mA+ phone/ipod AC-usb adaptor would make a fine combination. The little chip could probably use some heatsinking though if youre running 500mA though. But it has built in thermal limiting, so it wont roast itself, just limit current to < 500mA.


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## Lormar (Aug 16, 2010)

What about the Trustfire 3600 (!!!!) mAh ?
Has anyone already tested them?

3600mAh would be a huge capacity improvement...


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## jirik_cz (Aug 16, 2010)

Don't trust the trustfire numbers. Waste of money...


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## 45/70 (Aug 16, 2010)

As jirik said, don't go by the numbers resellers like TrustFire put on their cells. Most are inflated and some are down right ridiculous.

If a new higher capacity cell comes out, you'll hear about it first from an actual manufacturer, not a distributor like TrustFire, who merely buy up factory "seconds" from the manufacturers.

Dave


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## kreisler (Nov 10, 2011)

Hi. Old thread. But promising all-round 18650 cell, the Samsung. It's readily available on ebay (Hongkong sellers) and mass produced as is the Panasonic; both the Samsung and Panasonic are classified as "industrial cells" (with PCB, thanks God). The Samsung has a flat-top.

My 18650 flashlight is the EagleTac T20C2 MkII (it's a popular model i heard..), which accepts only button-top cells.

Has anyone tried to use the Samsung (which arent flat-tops but recessed tops!) with my *Eagtac T20*?


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## 45/70 (Nov 10, 2011)

,


kreisler said:


> ......both the Samsung and Panasonic are classified as "industrial cells" (with PCB, thanks God). The Samsung has a flat-top.



Hi kreisler. You might want to look back at posts #11 and #12. Samsung does not provide cells with PCB's added. There are no Li-Ion cell manufacturers that I am aware of, that do so. These cells are intended to be used in the making of battery packs for laptops and such. The packmaker is required beforehand, to have a protection dircuit designed specifically for the intend device these "packs" will be used in, before the cell manufacturer will even sell them the cells. This indirectly, applies to the nipples that have been added to manufacturer's cells, as well. Both protection circuits and nipples, present on cells of this type, have been added by third parties, or distributors such as AW, or Redilast, as these cells were never intended to be either sold, or used, individually by consumers.

I have two of the Samsung 30A cells that I bought from a Hong Kong vendor. These cells do not have added protection circuits, nor am I aware of any Samsung ICR18650 30A (or the 4.30 Volt 28A) cells that do. I'm not sure where Jason obtained his sample. Many Samsung, as well as Panasonic and other manufacturer's cells do have PCBs and/or nipples that have been added, but again, these cells will have either the vendor's, or distributor's label, not the actual manufacturer's label.

Dave


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## kreisler (Nov 11, 2011)

Thanks Dave for your elaborate answer. i am learning thru it 
i dont know of any end consumer 18650's (e.g. by UltraFire, TrustFire, lol) which are based on these Samsung industrial cells. I know that the XTAC 2600 are based on Sanyo cells.
Yah.. i will give up on the Samsung's then. I'll look out for the Panasonic's with nipples.

I've got only 1 flashlight with 18650's (the EagleTac); and with it, i bought 2x the XTAC 2600. i guess my supply for the next year(s) is covered with these 2 cells. haha 

Thanks again Dave, appreciated.


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## wshyang (Jul 20, 2012)

45/70 said:


> ,
> 
> I have two of the Samsung 30A cells that I bought from a Hong Kong vendor. These cells do not have added protection circuits, nor am I aware of any Samsung ICR18650 30A (or the 4.30 Volt 28A) cells that do. I'm not sure where Jason obtained his sample. Many Samsung, as well as Panasonic and other manufacturer's cells do have PCBs and/or nipples that have been added, but again, these cells will have either the vendor's, or distributor's label, not the actual manufacturer's label.
> 
> Dave



Hi,

I am looking to buy these cells also, but the cheapest place I found them at is DX. Is DX a legit source for these Samsungs?


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