Reserve Capacity (RC) - BCI (Battery Council International) defines it as "the number of minutes a new, fully-charged battery at 80ºF (27ºC) can be discharged at 25 amps and maintain a voltage equal to or higher than 1.75 volts per cell" (i.e., 10.5 volts for a 12-volt battery). This rating represents the time the battery will continue to operate essential accessories in the event of a charging system failure.