The voltage on my old battery was 12.4 volts with ignition off and 14 volts with engine running. Any idea how to reset BMS ?Was the BMS module reset when the battery was replaced? If you have a multimeter, you can check the voltage across the battery prior to starting then once started to check, in simple terms, if the alternator is providing any output. The charge current from the alternator is controlled by the BMS module so the output will vary as it charges and discharges the battery under normal operation. There's a few threads to have a read through as a few have had battery/alternator issues recently.