US Patent 10511209 Engine generator

An engine generator, including a general-purpose engine, a generator unit driven by the engine to generate electric power and capable of operating as an engine starter motor during engine starting, a case housing the engine and the generator unit, a battery detachably attached to the case, an inverter unit connected to the generator unit, and a power supply circuit interconnecting the battery attached to the case and the inverter unit and supplying power of the battery through the inverter unit to the generator unit.