Probably Bad BMS

[Philiptinyhouse]

Had my 280ah battery pack for almost a year and worked fine. Now when I was just gonna connect solar charge controller I always disconnect discharge and charge when connecting SCC or inverter. The cells are low but equal on 2.6V but the BMS sees 1 cell to 2.4V, checked for bad connection on that balance lead but not the problem. The main voltage doesnt go down more than 8V (12V system) when using the BMS to disconnect. I suspect the BMS are faulty or what do you guys think, still a newbie on this

 

[BentleyJ]

The BMS may be in "sleep" mode based on the 2.4V cell reading. Assuming your battery is LiFePO4, most BMS are set to disconnect at 2.5V and to go into low power or sleep mode if voltage continues to fall below that value. Sometimes its as easy as putting a charger on the battery and the BMS wakes up when the voltage goes back up.

This may require a stand alone charger as many solar charge controllers need the battery/BMS to function before they will start charging.