REDLITHIUM USB (universal serial bus) battery powers Milwaukee USB rechargeable products. REDLITHIUM USB battery delivers more run time, longer life, and faster charging. More performance with two times more capacity than three AAA alkaline batteries. Eliminate the need for disposable batteries with over 2000 charges for longer life. REDLITHIUM USB (universal serial bus) charger charges the Milwaukee REDLITHIUM USB battery. A 2.1 Amp charge rate delivers up to 3 times faster charge time. Get 50% of a charge in under 30 minutes, 80% in under one hour, and a full charge in 2 hours. Conveniently charge REDLITHIUM USB batteries via Micro-USB Cable from a wall plug or USB power source. Includes USB wall adapter and 2 Ft. heavy-duty USB cord. 2 year warranty.