Sudden cut off. Stop turn battery off then back on and it runs again. The battery pack shows nearly full charge and will be reading @47 volts. The individual cell packs in the 13s 48 volt battery read evenly @3.9 volts when testing with my volt meter on the kitchen table. Do you suspect the bms is bad or have my 18650 cells lost their ah capacity? Why would it drop out when showing a fair amount of voltage?