Method for regulating battery power in a vehicle

Total electric output (Pg) consumed by a motor vehicle is produced by a generator (3) coupled the vehicle's internal combustion engine (2). A cost function is calculated, which represents an amount of fuel excess consumption regarding total electric output yielded by such consumption. An optimum value is determined for battery yield so that the cost function is minimized. An Independent claim is also included for a controller for regulating electric battery power in a motor vehicle's main power supply.