The Faithfull Power Plus 7.4V 8800mAh Li-ion Battery may be used to provide extended running times for the FPPSLLED20TB Cordless LED Site Light to supply continuous illumination. This additional battery allows the battery packs to be cycled as a when they become exhausted and is particularly useful when no other power supply is available. The battery can be independently charged using either the mains or car charger and can also be recharged while the lamp is in use when a power source is available. Specification: Battery: 7.4V 8800mAh Li-ion Charging Time: Approx. 4 hours