Most of these have a carry case that contains a battery, so the idea is that as you store them, they charge, giving a much longer overall battery life. (t3.com)
Even on days when I was on cellular data throughout, I managed to get up to four hours of screen - on - time and overall battery life exceeding 20 hours. (androidcentral.com)
The Bionic currently has the best overall battery life of all the LTE phones on Verizon. (phonearena.com)