An engine includes at least one piston, a rotatable crankshaft, a starter motor, a lithium-ion battery, and a charging system. The rotatable crankshaft is coupled to the at least one piston. The starter motor is configured to selectively initiate rotation of the crankshaft. The lithium-ion battery is in electrical communication with the starter motor and has at least one cell. The charging system is powered by motion of at least one component of the engine. The charging system provides energy to the lithium-ion battery to charge the lithium-ion battery. The engine has a starting condition, a miming condition, and a stopping condition. The charging system continuously applies a voltage potential to the at least one cell while the engine is in a running condition.
