An improved method and apparatus for powering an electric motor for starting an internal combustion engine in which the electric motor is in a 6 volt to 48 volt operating system, in which an auxiliary battery pack has a battery pack housing; at least one lithium-based rechargeable cell within the housing; associated means for receiving a radio transmitted signal; associated means for turning the rechargeable cell ON or OFF; and battery connections for connecting the auxiliary battery pack to a battery in a 6 volt to 48 volt operating system.