Multiple function current-sharing charging systems aid methods are provided. Where first and second rechargeable power supplies are connected to a charging system, a first charging current is provided to the first rechargeable power supply and a second charging current is provided to the second rechargeable power supply. Upon detection of a predetermined charge level of one of the rechargeable power supplies, a third charging current is provided to the first rechargeable power supply and a fourth charging current is provided to the second rechargeable power supply.