US Patent 9127658 Internal combustion engine including starting system powered by lithium-ion battery

An internal combustion engine includes an engine block including a cylinder, a piston positioned within the cylinder, a crankshaft configured to be driven by the piston, a fuel system for supplying an air-fuel mixture to the cylinder, and an electric starting system including a starter motor, a battery receiver, and a lithium-ion battery removably attached to the battery receiver, wherein the lithium-ion battery is configured to power the starter motor to start the engine.