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Mar 12, 2019, 08:03 AM
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MikeJM's Avatar
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Question

A123 batteries


Has anyone used Radical RC custom sized A123 batteries. Just curious if there is any quality/ performance issues.

Mike
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Mar 12, 2019, 09:01 AM
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I have used Radical products for years with no problems.

BUUTT

Never used their A123 cells or packs. The specifications on the charging & storage voltages has some errors. They should PROOF read what they are about to post Maybe there has been a change in help ?
Mar 12, 2019, 03:21 PM
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Zeeb's Avatar
I use Richard at WrongWay RC for my A123 packs. He'll build 'em any configuration you want, matches cells for packs, does really nice work and good prices;

http://www.wrongwayrc.com/
Mar 12, 2019, 03:40 PM
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barracudahockey's Avatar
+1 to WrongWay!
Mar 12, 2019, 05:26 PM
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Excellent, any other trusted custom pack builders experienced using A123?

Want to avoid solder-welding joins if possible, or is that the norm?
Mar 12, 2019, 05:30 PM
Registered User

loads of GOOD / great soldering guys have soldered cells together.


I always used 2 or 3 " jumper wires between tabs. Makes the job SOO much safer & reliable. Piece of cake. No over heating the 2 tabs or dripping solder.
Mar 12, 2019, 06:42 PM
Registered User

commercial builders


I meant when paying for an assembled pack.

I realize that's how DIYers roll here.
Mar 12, 2019, 07:25 PM
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vollrathd's Avatar
Quote:
Originally Posted by John61CT
Excellent, any other trusted custom pack builders experienced using A123?

Want to avoid solder-welding joins if possible, or is that the norm?
I've been building up custom A123 packs for some 10 years now. My own collection is over 200 cells, one of which is a 12S3P 7500 mah pack, used on a 4500 Watt electric model.

Soldering these cells is a lot easier if you have the proper equipment. I use a Weller 100 Watt temperature regulated soldering iron with a 3/8 inch diameter iron plated copper tip. That works very well.

A123 sells them at $7.75 per cell with a 10 cell purchase. Add to that, a flat $20.00 shipping charge. Right now, they are out of stock. The last time I checked a month ago, they had over 6000 cells in stock.
http://a123batteries.com/anr26650-li...-anr26650m1-b/

Attached are a few photos of how I build them up.
Mar 12, 2019, 09:45 PM
Registered User
That doesn't seem to allow individual cell monitoring and balancing?

So, 6P would mean nominal 15Ah units.

1 kWh bank, say an 80Ah 12V pack is 32P4S, so $1000, $1/Wh just for the bare component cells. . .

Cheaper than big prismatic CALBs, but still pretty fiddly when a big bank, hundreds of amps, is needed.

Really would like a way to swap cells out with basic tools.
Mar 12, 2019, 09:49 PM
Registered User
marginally relevant

https://www.diyelectriccar.com/forum.../topics/199865
Mar 12, 2019, 09:53 PM
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Zeeb's Avatar
Quote:
Originally Posted by John61CT
That doesn't seem to allow individual cell monitoring and balancing?

So, 6P would mean nominal 15Ah units.

1 kWh bank, say an 80Ah 12V pack is 32P4S, so $1000, $1/Wh just for the bare component cells. . .

Cheaper than big prismatic CALBs, but still pretty fiddly when a big bank, hundreds of amps, is needed.

Really would like a way to swap cells out with basic tools.
Sorry but I think that you are looking in the wrong place. While there are some here who will know exactly what you just said and want, most of us are model airplane hobbyists and are not interested nor have the knowledge, to achieve what you want.
Mar 12, 2019, 10:45 PM
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vollrathd's Avatar
Quote:
Originally Posted by John61CT
That doesn't seem to allow individual cell monitoring and balancing?

Really would like a way to swap cells out with basic tools.
There is a three wire balance lead for balance charging those two cell A123 receiver packs.

For very high Amp Hour capacity, check EBay for 20 Amp Hour cells. And, yes, it will be danged expensive.
Mar 12, 2019, 11:54 PM
Registered User
The 3.3V cells within each pair are not treated individually right, monitored / balanced only as a pair?
Mar 12, 2019, 11:55 PM
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Quote:
Originally Posted by Zeeb
most of us are model airplane hobbyists and are not interested nor have the knowledge
Yes, feel free to just ignore.
Mar 13, 2019, 12:19 AM
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vollrathd's Avatar
Quote:
Originally Posted by John61CT
The 3.3V cells within each pair are not treated individually right, monitored / balanced only as a pair?
If you look at the first photo in report #8 in this thread, you will see there is a black wire and a red wire on the left side of the battery pack. Those two wires are brought out to the three wire balance plug. And, if you look at the right side of that battery pack, there is a white wire on the center of the two cells. That white wire is also brought out to the balance plug. Any quality Lithium type battery charger now days allows monitoring the voltage of each cell in a battery pack while charging that pack.

FYI, it's just about mandatory to provide cell balancing for any Lithium type battery. And, that includes the LiFe and A123 packs.

Some 10 years ago, I built a charger to charge five cells, six or seven A123 cells at a fixed ten Amps. The charger operated on the Constant Current, then Constant Voltage process same as used by these Lithium chargers today. And, didn't provide for balancing. After a year or so, one of the cells in a 6S A123 pack developed high internal resistance. Didn't take long to find that this cell was being charged to some 6 Volts during the charge cycle.

So, I designed and built a balancing board for that charger. After a couple of years, I bought first one, then another Cellpro PL8 charger, and never looked back. (Still have those home built chargers and its matching balance circuit, and they still work)


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