A vehicle starter assembly includes a switching circuit configured to operate in a charging state and a discharging state, and a first energy storage device and a second energy storage device electrically connected to the switching circuit. The first energy storage device and the second energy storage device are connected in parallel to one another in the charging state and in series with one another in the discharging state. The processor is programmed to detect an engine start request and output a switch control signal that toggles the switching circuit between the charging state and the discharging state to start an internal combustion engine of a host vehicle.