BlackburnPete
1 W
I just noticed my battery charger was going on and off every couple of seconds. I have a 16S1P A123 LiFePO4 pouch battery pack that has been working flawlessly since of 2013. I have a Kingpan 5A charger that always charges my pack to 58V. After shutting down the charger, I checked the overall total pack voltage at 55V. I naturally assumed one of my cells was non-responsive. I opened up the pack and checked the voltage across all the cells with the BMS still attached. Each cell was at 3.35V equally. I plugged the charger back in and checked each cell as they were charging. One cell was charging much faster than the others. I immediately shut off the charger and all cells were once again at 3.35V except the suspect cell that was up at 3.51V but it was falling rapidly as I held the voltmeter on that cell. Eventually, I expect that cell will return to 3.35 like rest of them. I think the BMS must be recognizing a high voltage in that cell and shutting down the charger, but as the cell self-discharges, the charger thinks the pack is OK and starts charging again. This repeats every couple of seconds.
Does this sound like a reasonable explanation?
Next, I will try to unplug the BMS overnight and see where the cell voltages end up by morning. I suspect the problem cell will be more obvious by then.
Does this sound like a reasonable explanation?
Next, I will try to unplug the BMS overnight and see where the cell voltages end up by morning. I suspect the problem cell will be more obvious by then.