Well I think I can do you all one better, or worse as the case may be. I had
eight A123 86 volt, 5 kWh battery modules in my electric conversion and managed
to accidentally leave the key turned on overnight. Result, at least four of
the modules developed one parallel cell group of three cells that would not
come back when charging the pack. The modules are made up of 78 pouch cells
divided into 26s3p.
So after weeks of therapy, I started wondering what I could do with all these
modules and cells. My question is, has anyone ever tried to rebuild or replace
pouch cells in A123 modules? The cells seem to be welded in some areas with
metal connections that might be crimped to the taps on the individual cells.
Any and all comments appreciated. David
On Tuesday, November 28, 2023 at 06:17:20 AM PST, Bill Dube via EV
<ev@lists.evdl.org> wrote:
The A123 26650 M1-B cells will throw over 200 amps to a short circuit.
Considerably more if they are at optimum temperature. :-)
The short circuit current will actually go up as the cell heats up. This
assumes that whatever caused the short hasn't vaporized....
These are _very_ well designed cells. They will last over 10,000 cycles
BTW. 100% discharge and charge at 1C rate, 20 Celsius, and retain more
than 50% of the original capacity. No Joke.
Bill D.
On 11/28/2023 6:15 PM, Cor van de Water via EV wrote:
> Lawrence, when I removed some of the cells from that pack that you picked
> up, I cut the straps with heavy duty scissors.
> One time I accidentally shorted the cell I was removing while cutting and
> the current was large enough to bite a chunk out of the scissor blades...
> These are *very* low resistance cells, so the short circuit current
> consequently is very high, even at the low 3.5V of a single cell.
> Cor.
>
> On Mon, Nov 27, 2023, 9:06 PM Lawrence Rhodes via EV <ev@lists.evdl.org>
> wrote:
>
>> https://youtu.be/zEXx_2Caefc?si=j66-Advfy42A7-Aq I wasn't too careful
>> separating some cells. Nicked a few. Used in flashlights they are awesome.
>> However, I nicked a few near the base and my hacked flashlight spring
>> shorted the cell. Smoke and brown fluid. Oops. I will tape nicks and avoid
>> making them in the future. Also use an adapter of pvc for extra safety.
>> Lawrence Rhodes
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