FAQ: Battery Overcharged – What to do?

In case of failure to charge properly, the overcharge will result in damage of the internal cell structure. In base of mild overcharge, there is some chance to recover the function of the cell.

If overcharge happens, follow these guide lines:

1) Remove the charger and stop charging immediately.
2) Discharge the cell slowly with reasonable currents (bellow 0.1C, bellow 10A for 100Ah cell). The discharge should last until the voltage drops to normal level (e.g. 3.2V for LFP cells)
3) While discharging, open the safety valve to allow the internal pressure to release. (Not all cells have the safety valve designed to be opened. Please contact us for specific instructions.)
4) If the cells are swollen, we suggest to follow the instruction to press the cells back to their original size (see details here).

After the cells have been restored, we suggest to make some testing cycles to see the performance of the cell. (E.g. 5 to 10 cycles). For cells that were overcharged by mistake, we strongly suggest to avoid repeated charging them to full voltage. Charging to 80% ~ 90% level of nominal capacity is a good way to avoid further degradation of the cells that were already overcharged.