WORX WA3512.1 18-Volt Lithium-Ion Cordless Tool Battery 18-volt lithium ion replacement battery for use with WORX cordless powered models Provides 3 times the useable life of standard Ni-Cd batteries Charges quickly for long-lasting use; runs at 100% power through the life of the charge Lithium Ion batteries have no memory effect and self-discharge is minimal Ultra lightweight; measures 9-2/5 by 7-3/5 by 4 inches