The Chaheati Maxx 11.1V replacement battery was designed for the Chaheati Maxx product line. The rechargeable battery provides up to six hours of heat; 2 hours of heat on high, 4 hours on medium and 7 hours on low. The rechargeable battery has a USB port to charge your phone or tablet while you heat your chair. It provides just the right amount of heat in any season. Now there's no reason to pack it in early when the weather turns cool outside. Just grab some heat with Chaheati