A snowthrower includes an internal combustion engine and a starter battery pack that provides electrical power to operate an electric starter motor. The starter battery pack is received within a receptacle of the snowthrower and is selectively coupled to the starter motor to initiate operation of the internal combustion engine. The starter battery pack can further include a battery heating circuit that is operable to heat the starter battery pack above ambient temperatures to increase the current output of the starter battery pack. The battery heating circuit includes a controller that utilizes electrical power from the starter battery pack to heat the starter battery pack.