Have 2 - 100 amp sok batteries installed in our RV. Since we do not do a lot of Boone docking the main function of the batteries is to provide power to the 12v system and to power via a 3000w Aims inverter for the fridge and minor appliances. The Aims is an inverter/converter and because of the a/c wiring the inverter stays one whenever the RV is in use. The system is wired with a shunt and monitor. I realized today the batteries stop charging at 12.7%. If I intentionally drain the batteries to cut off an reconnect to the charger they charge normally until they hit 12.7% and then stop. Any suggestions? Does this mean one or both batteries have a defective bms?