How to reset your power tool battery if won't charge?
if your battery won't charge, here are several simple steps to save your money on buying a new one.
First of all, test if the battery is over low voltage. Long time discharge or over drain may cause this issue. You can restart it easily with 2 wires by connecting with a fully charged battery "+"to"+"/"-" to "-". There are many videos on YOUTUBE for reference. You can reset it by 110V to 20V Power station. PLEASE NOTE THAT the input current should be lower than 1Amp hour.
Secondly, if you can't reset the battery by STEP 1, you may need to disassembly the battery and test all the battery cells. Find the one defective and replace it. If all the battery cells seem to be fine, the BMS board maybe dead then. Honestly, we can do nothing on this situation.
Sorry, nearly forget to remind you to try other chargers.