It could be essential to use an external charger to charge the battery if the voltage is low. . The system has run flawlessly for the last 4 years or so but recently has started to give me a low voltage error around 67% remaining charge. I am curious about what needs to happen to get my system back to error free performance? Batteries have never been run below 50% and we use the cabin about. . Checked cell voltages, 2. Did the BMS shut it down due to the low cell voltage? Should I pull the buss bars and charge the low cell or replace it? Purchased cells Nov 2020, have not balanced cells since initial install. Yes, the BMS probably shut down at 2. Sometimes, due to various reasons like long periods of cloudy weather, high energy consumption, or aging batteries, the voltage in the battery can drop below the normal operating level.