Possible new multi cell Li-Ion Universal Balanced charger setup

[LuxLuthor]

We are really talking about the top image. You then need a charger that does individual cell balancing, and that has enough amp output to do however many cells (new "C" size are more demanding) you want to do at a time.

Some of the more advanced chargers require a separate balancing module, but there are models that come with that capability. I wish it was an easy...get this charger....type answer.

Some have suggested this might be all you need to do 4 cells safely, with the cradle. I ordered one of these, even though I already have a more elaborate Hyperion charger setup...to see how it works for the community.

 

[cy]

running a Nippon America DVP-2212 regulated 20amp power supply here with Schulze 6-330 d

delivering enough amps to support 4 C li-ion cells will not be a problem for me. Wall warts is not going to do it. I see no reason why used PC power supplies could not be used.

Silver and Jar is bringing out information about under what conditions dendrites are formed.

which is under trickle charge after cell is fully charged and during discharge at higher than current specified.

normally lithium ions are transfered between cathode and anode in a rocker fashion. the metal lithium is normally never formed. however under above conditions the metal lithium is deposited forming as a dendrite growth. sharp points could then puncture insulating barrier, leading to rapid disassembly of cell.

these larger cells should be charged at .5C to 1C. for 4 3amp cells that would be a whopping 12amps to parallel charge.

 

[matrixshaman]

I haven't read the whole thread here but thought I'd throw this in. As far as cell holders go I've got an old charger made for alkalines and NiCd that can be converted but I checked eBay to see if I could find something similar and found these for around $20 and I've seen others for similar or less: Should be easy to get into it and disconnect THEIR charging power supply to hook your own up: Link to one example
Not sure but might be a way to save on the cell holder/charger - this one claims to even be a smart charger that does NiCd, NiMH, Alkaline and holds AAA, AA, C and D.

 

[petrev]

Hi

The DN/Tenergy as above is good for 2A 4Cells and that offer includes a small but hopefully adequate power supply.

FMA CellPro 4S - 3A upto 4Cells full auto or set it yourself rates and Data output - needs power supply

FMA BalancePro HD 6S - 0.5-10A 2-6cells set yourself max rate (pot=caution) and Data-Out - needs power supply adequate for number, size and speed desired

As stated by cy decent supply needed the bigger the cells and the more at once even in series balanced mode (power 4*3.3A*4.2V par or 3.3A*16.8 series = same)
eg. perfect conversion 3.3A for 4 cells is 4.5A@12V input
6 cells = 6.9A@12V

If we ever get D LiIons well . . . 5200mAh

I haven't read the whole thread here but thought I'd throw this in. As far as cell holders go I've got an old charger made for alkalines and NiCd that can be converted but I checked eBay to see if I could find something similar and found these for around $20 and I've seen others for similar or less: Should be easy to get into it and disconnect THEIR charging power supply to hook your own up: Link to one example
Not sure but might be a way to save on the cell holder/charger - this one claims to even be a smart charger that does NiCd, NiMH, Alkaline and holds AAA, AA, C and D.

The Universal charging cradle above is designed for series-charging so fits with balanced system perfectly (we hope) - Standard NiCad/NiMh chargers look the same but are parallel/common wired at the neg ends so would need major rewiring ( they often have a common metal bar accross all neg terminals holding the spring loaded cell clamps). If you have an old/broken one then would be a fun project. I've just got some 4way d-batt boxes to make a temp cheap starter cradle till the better stuff arrives as I expect my c-cells any day

Hope this helps

Cheers Pete

 

[LuxLuthor]

Silver and Jar is bringing out information about under what conditions dendrites are formed. which is under trickle charge after cell is fully charged and during discharge at higher than current specified.

normally lithium ions are transfered between cathode and anode in a rocker fashion. the metal lithium is normally never formed. however under above conditions the metal lithium is deposited forming as a dendrite growth. sharp points could then puncture insulating barrier, leading to rapid disassembly of cell.

these larger cells should be charged at .5C to 1C. for 4 3amp cells that would be a whopping 12amps to parallel charge.

I saw that beautiful color image of the crystal-like dendrite. I know Tom will give a great explanation, but is it basically something that happens only with trickle charging of Li-Ions? If so, any way to tell it is happening in terms of measurements?

I now understand the safety reason for doing the parallel charging, as long as the starting cell voltages are within 0.2V of each other, but if this 4-slot cradle works out with taps, is there any reason not to use charging C cells in series (with taps)? That might allow people to get a unit like the Tenergy as an easier to use, safe, and relatively affordable package?

 

[LuxLuthor]

Hi

The DN/Tenergy as above is good for 2A 4Cells and that offer includes a small but hopefully adequate power supply.

FMA CellPro 4S - 3A upto 4Cells full auto or set it yourself rates and Data output - needs power supply

FMA BalancePro HD 6S - 0.5-10A 2-6cells set yourself max rate (pot=caution) and Data-Out - needs power supply adequate for number, size and speed desired

As stated by cy decent supply needed the bigger the cells and the more at once even in series balanced mode (power 4*3.3A*4.2V par or 3.3A*16.8 series = same)
eg. perfect conversion 3.3A for 4 cells is 4.5A@12V input
6 cells = 6.9A@12V

If we ever get D LiIons well . . . 5200mAh

The Universal charging cradle above is designed for series-charging so fits with balanced system perfectly (we hope) - Standard NiCad/NiMh chargers look the same but are parallel/common wired at the neg ends so would need major rewiring ( they often have a common metal bar accross all neg terminals holding the spring loaded cell clamps). If you have an old/broken one then would be a fun project. I've just got some 4way d-batt boxes to make a temp cheap starter cradle till the better stuff arrives as I expect my c-cells any day

Hope this helps

Cheers Pete

Not having an electrical background, for some reason, I'm still not figuring out those series V * A calculations for "C Cells 3300mAh" example you posted. Here's my simpleton's understanding with my Hyperion 1210i setup if I was going to charge three of the 3300 mAh cells in series with balancer taps.

I would set it for 3S (11.1V) and up to 3.3A if I wanted to charge at 1C rate. I am assuming that this would be as safe (with balancer) as charging them in Parallel, but take longer.

My Pyramid power supply (which I got from CheapBatteryPacks.com on bottom of link here) says that it delivers 10A constant with 12A peak, so theoretically I could use it to charge three of the C cells in parallel.

If my understanding is correct, and if these 4 slot cradles are wired in series, and if balancer is used, wouldn't it allow people to use this Tenergy w/ 5A AC power supply package?

matrixshaman, I think there are a number of those kinds of holders that could be re-wired like you linked, but we are trying to find a relatively simple combination of cradle & balancing charger that will allow people to start charging most of their Li-Ion cells safely, & without having to remove the various PCB's, and rewiring correctly. Again, the most amazing thing to me is the total lack of a cradle setup for all the Li-Ion cells out there. Even the Voltic brand we are looking at specifically says it is for NiCd and NiMH on the package. Clearly, this is an opportunity for some manufacturer/dealer.

I'm also thinking it might be nice to have a safe way to use the 4 slot cradle we are looking at to switch it between series and parallel. That would open up even more capability for those who don't have (or want) a balancing charger to do multiple cells (assumes a higher Amp PS though).

 

[petrev]

Hi LL

Yes - that package should be fine - I am just doing rough calculations using good old P=IV
eg P=2(A)*4(V)*4(cells)=32W
input=12V
Iin = 32/12 = 2.7A
So 5A should be OK
10A supply should be good for [email protected]

but I am no expert . . .
Cheers Pete

 

[petrev]

Hi All

Heath Robinson designed Charger Cradle



CellPro 4S PigTail


SIZES - C - D - 17500 - 17650 - (Caution: sizes for demonstration purposes only / do not mix cells / LiIon charger not for NiMh / etc . . .)


2 Cell Balanced Charging (spare nodes parked) (Caution: do not attempt to charge NiMh with LiIon charger etc.)


Not Idiot Proof - but straightforward ? Oh Yes - I will label the Sockets - . 0 . 1 . 2 . 3 . 4 .

Available to purchase at cost (parts) when I get my Voltcraft ones and wire them for 6S ! ! ! in the mean time - hope my "C" cells arrive Monday/SOON

Cheers Pete

 

[cy]

I'm so in for one!!!

thank YOU!

Hi All

Heath Robinson designed Charger Cradle


Available to purchase at cost (parts) when I get my Voltcraft ones and wire them for 6S ! ! ! in the mean time - hope my "C" cells arrive Monday/SOON

Cheers Pete

 

[petrev]

Thank you cy

Now adapted to fit - Protected AW17670 and AW18670 (Thank you Mr. Dremel)



Cheers Pete

 

[LuxLuthor]

Ha! Well that will do the job, and as they say "Necessity is the Mother of Invention." Rube Goldberg would be proud!

 

[Nebula]

Pete - I have that same holder as well as a few single holders. I would like to take a shot at duplicating your work on this side of the pond. Can you can ID the circuit board and pig tails by their part numbers, and supplier? Better yet, can you post a diagram of your rig?

BTW - Nice job. You may have more orders than you can keep up with.

Cheers

Kirk

 

[petrev]

Pete - I have that same holder as well as a few single holders. I would like to take a shot at duplicating your work on this side of the pond. Can you can ID the circuit board and pig tails by their part numbers, and supplier? Better yet, can you post a diagram of your rig?

BTW - Nice job. You may have more orders than you can keep up with.

Cheers

Kirk

Hi Kirk
Thanks

FMADirect.com - (UK Aurorra.co.uk call Mike for any unlisted parts - very helpful)

Deans Ultra, 5 Position Series Connector Module Part Number: CMS-HC-5

5 X Deans Ultra Connector (Female) Part Number: DNS-7092

Cellpro battery pigtail 7" Part Number: CPBP7

Only connect PCB-Pos Terminals and Pos-lugs on female plugs.
Black and Red heat-shrink as per photo
Wire as per photo (colours as you wish)
Solder to Tabs (+) and (-) and the three spring connector wires for Nodes 1-2-3 (drill small holes at appropriate points)

4 x Black Philips head screws to mount carrier
4 x Smaller Philips head screws to mount Connector Module
2 x Plastic ring-standoffs to match height of under-side lugs

1 x Piece of 15mm plywood (Grey Speckled Melamine laminate optional)

4 x pieces 3.5mm rubber foam-mat support C-cells at correct height (optional)

Cuts to allow long sides to "flex" fit for 17670 and 18670 cells.

Number module connectors 0 - 1 - 2 - 3 - 4
0=Neg
N=Cell.N+ (or node.N)
Fit POS connection to last Cell+ and connect intervening nodes - see photo 4
Park unused Node-Connectors - see photo 4

Any questions - just ask

Cheers Pete

 

[Nebula]

Pete - Many thanks for the excellent info, and thorough post. I will let you know how things turn out. Cheers. Kirk

 

[petrev]

Pete - Many thanks for the excellent info, and thorough post. I will let you know how things turn out. Cheers. Kirk

Good luck - Keep us posted
Pete

 

[Tronic]

A few pics of the voltcraft cradle that I have purchased today.



with 10280 battery .....the max lenght is 62mm


the slots are all wired in serial

 

[petrev]

Great Pics - Thanks Tronic

Must have a store near you ? I Just ordered some and it's 5-6 day delivery within UK.

Just about as good as we could expect. Like the wires down the springs - I'll get to that in a minute . . .

Some of my NiMh-D 7000mAh are 61.3mm long - so much for standards - Guess there will be some Dremeling to fit longer cells !

But overall they look great :goodjob: .

Now to my work today -
My "C" cells arrived - brilliant service AW - Ta.

They are great little beasts - look loverly.
So fitted into Batt-Cradle and start charging at 3A - All well - then ERROR.

Spoke to the man at SMADirect who designed them - great chap - and he looked at my photos from this thread and it turns out the BalancePro-6S is so clever that it worked out the springs are a bit on the resistive side and the Volt drop accross them upsets it so it won't charge at more than about 2A as it thinks it might melt some thin wires. This is very sensible as it can charge at upto 10A and that would heat things up very nicely.

Charges perfectly at 2A but still warns you about the "Thin" wires.

The CellPro-4S (also his baby) will apparently charge 4 cells at 3A without worries as it never expects to heat things up too much at that max-rate.

Charged my first 4 cells at 2A and this is what the data looks like

.

Started out reading about 45-50% "Fuel"
Reached 98% at about 45 - 50 minutes at 2A rate
Topped off to 100% 4.2V after 1hr 16min

Charged a second set and put 5 in my 6C-5LiIon-IRC50.
Took a couple of clicks - no surprise - and it looks great.

More testing follows.

Back to the point - can't wait for my Voltcraft cradles to arrive . . .

Cheers Pete

 

[aosty]

I'm so in for one!!!

thank YOU!

Me too, please!!

 

[LuxLuthor]

Great pix, Tronic ! These will work perfectly, and be easily hooked up in series. I can see how easy it would be to convert one to parallel for those who don't have a balancing charger, but I'm seeing this as a nice combination with that Tenergy/converter package that was mentioned earlier.

It looks like my Pila 600s cells are 68mm long, so I'll need to get 7mm somewhere...probably the metal contact arms. Hmm...standing it next to a D-cell, it only looks about 5mm taller than the D cell nipple.

 

[Nebula]

Lux, Pete and Tronic - I just want to THANK YOU for your dedication and determination in locating, testing and modifying these devices. I really do hope that we can find a way to get a GB on the holders. It would also be nice if we could have the option of purchasing the single cell holders as well. I am more than happy to assist in any way that I can. Just say the word.

Thanks again for your efforts. We may just find a safer, albeit never entirely safe, method of charging our Li-ion cell.

Cheers

Kirk