A123 capacity test (Full Version)

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rajul -> A123 capacity test (10/2/2007 4:43:54 PM)

Hi, what discharge rate and minimum voltage should be used to check the capacity of a A123 cell? Thx



guver -> RE: A123 capacity test (10/2/2007 4:49:31 PM)

The factory is using 1,10,30,40 amps and 2 volts according to the chart. I'd try to match that. Or can set your own standard close to your real world conditions.



rajul -> RE: A123 capacity test (10/2/2007 4:56:05 PM)

Does the cell get damaged if the voltage goes below 1V?



guver -> RE: A123 capacity test (10/2/2007 5:25:54 PM)

not sure, well maybe somewhat. I've seen many cycles,abuses posted with very little damage. They sure are a lot heartier than a lipo.
Much more forgiving for under/over voltage.



everydayflyer -> RE: A123 capacity test (10/11/2007 4:50:39 PM)

2 volts per cell LVC is the recomended min. however myself and others have gone lower.
One single cell test on RC Groups was to charge to 4.3 and discharge to 0 (zero).

Cells should no be left discharge below 2 V and 3.3 is the standard storage voltage. With packs balance should be monitoried especially when discharged more than 2000 mAh which is the point where imbalance starts to get bad with some packs.

Charles



Red Scholefield -> RE: A123 capacity test (10/11/2007 7:01:55 PM)


quote:

ORIGINAL: rajul

Hi, what discharge rate and minimum voltage should be used to check the capacity of a A123 cell? Thx


Manufacturers usually set the rating at C/10 discharge. For all practical purposes there is little capacity left below 2.5 volts so to be safe set this as you cut off. Realize that the higher the discharge rate the lower you can go in the cut off voltage without damaging the cells.



everydayflyer -> RE: A123 capacity test (10/24/2007 2:51:47 PM)

One should also be aware that battery temperature will effect discharge capacity and voltage curve.Much like LiPolys and Ni cells these perform beter when a little warm.

Attached is acouple of old CBA Graphs of mine showing difference at 11.5A discharge rate and two different temps.



Charles



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