Keep your WORX WG151.5, WG251.5 or WG540 always at the ready, especially for those big jobs, with this 18-volt lithium ion replacement battery. Designed to charge quickly for long-lasting use, lithium technology provides three times the useable life of standard Ni-Cd batteries and runs at 100-percent power through the life of the charge. Another convenience, the battery may be charged at any point during the charge cycle without reducing its effectiveness or lifespan. Ultra lightweight and compact, the replacement battery measures 9-2/5 by 7-3/5 by 4 inches.