Some embodiments relate to a power management system. The power management system includes a generator that provides a voltage output to a bus. The bus is adapted to be connected to a load. The power management system further includes a battery charger that is adapted to charge a battery. A generator controller operates the generator and also adjusts operating conditions of the battery charger. In some embodiments, the generator includes an internal combustion engine that drives an alternator. Embodiments are contemplated where the battery charger is adapted to receive power from a primary power source. As an example, the primary power source may be utility power or some other form of generator power.