The built date of my A7 phone puts it at 2 yrs almost to the day so it may have been in use for 18 months. Already the battery life is 4-5 hours max. That is with bluetooth, location, gps, and unnecessary stuff off. I sometimes get the baadaadaa, dead battery noise as phone turns off, only to turn it back on and have 30-40% left. I like the phone, but don't see another ZTE product ahead as they make it impossible to change battery myself. Are batteries good for 2 yrs and then buy a new phone? I can't afford that.