A power source apparatus includes a power generation device, a battery and an overcharge protection circuit. The overcharge protection circuit includes a shunt circuit, including a switching device for short-circuiting the power generation device when an input signal is at an `L`...http://www.google.co.uk/patents/US5714869?utm_source=gb-gplus-sharePatent US5714869 - Power source apparatus with battery and overcharge protection circuit
