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Old 11-22-2015, 10:07 PM   #13 (permalink)
S Keith
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If you follow my suggestions, you should be fine. Your pack is broken. You're not going to make it any worse.

You WILL reverse cells. Period. The key is to do it at low current and in stages to minimize time and duration at reversed polarity. This is why I suggested 250W to 135V, then 60W to 60V. Of course, this is after a grid charge, and your starting voltage doesn't look very grid-chargy.

0.78V is the threshold at which voltage depressed cells will yield their remaining capacity. Powering through this level at low current generally restores high-current capacity.

Steve

EDIT: I've run IMA and Prius packs down to < 2V TOTAL voltage at very low current (<200mA). You're not going to hurt anything. The folks over at Insight Central are doing this routinely. Reversing 1-2A consumer grade cells will kill them. Reversing 100A industrial cells at very low current does no measurable damage.

BTW... The concept of X Volts per cell goes out the window below 1V/cell. When you go <1V per cell, you can more accurately describe it as "Pack Voltage = # of cells that haven't reversed".

Last edited by S Keith; 11-22-2015 at 10:16 PM..
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