Our all-new, cutting-edge MaxLithium™ technology gives you the same great features of any lithium-ion battery - with 50% more runtime than an 18V model! Forget about self-discharge, as you will experience full power until the end of the battery charge. Don't worry about leaving this battery on the charger, because there is no memory effect. This 20V MaxLithium™ battery is our most powerful and longest-lasting battery ever offered!