Battery Chargers by BikeMaster. Details:If you have a Lithium battery, don't damage it by charging it with the wrong type of charger. This charger has been designed to keep your BikeMaster Lithium-Ion batteries fully charged. Manufactured with over 11 ft. of reach, the BikeMaster Lithium-Ion Battery Charger/Maintainer is fully automatic with built-in circuit protection to keep from overcharging, short circuiting or reversing polarity. It features easy-to-read LED lights that indicate when power is on, charge in process, reverse polarity and fully charged.