Currently I am using an extended battery just to be safe. I ordered it online from mpj for a try when I bought the phone. Thought my original case of ZTE Avail no longer fits, but it actually slim as the stock. Battery life wasnt good at first, much better after several full recharge cycles (is manage to last around 2 hrs longer). My only problem for now is that the original case is a little brittle right by the volume and power buttons:/
