The E-Series Backpack Blower uses Bad Boy’s universal 80-volt battery system. That means every Bad Boy battery is interchangeable and can power any piece of E-Series equipment. Our 80V batteries offer more torque, more performance and most importantly, longer-lasting run time. The E-Series Backpack Blower comes with a 5.0 Ah battery that delivers up to 25 minutes of run time. (A higher Ah number basically means the battery will last longer before it has to be recharged.) Plus, the Backpack Blower has a second battery port, so you can add another battery and double your run time. Just pop it in, and use the battery capacity indicator (BCI) button to see how much power you have left.