Mine stays at 100% for a while even though I know better because its been off the charger for a while,I go to about phone it shows 100%.I reboot it and might get a 75-82 % .Cant figure it out any Ideas.
Mine is going from 100% to 90 % in about 15 minutes. I am going to calibrate the battery to see if that solves the problem. If it doesn't, then I will be making a trip to the AT&T store to have them swap it out.
Seems to be related to using a non-samsung charger, or maybe just chargers designed for Apple products. Mine does it every time with my u-socket, but not with the Samsung wall-wart or HP TouchPad charger.
Mine will be at 100% for a hour or so then I reboot and It might say 83%,so I went out bought another battery(att told me to try this first)and its the same crap so its not the battery.
I think it has to do with the charger. Are you using a different charger other than the Samsung one that came with the phone. I had this problem for a while and was using a different plug in the outlet. Once I switched back to the Samsung charger that came with the phone the problem stopped. You should try this.
Just to update, 3 weeks in I went back and they exchanged the device for me. Same thing happened. So 2 days before my 30 days was up I just returned it. At&t rep told me to wait for an update, except I wasnt gonna wait for an update that may not fix the issue. Really liked the phone, but the battery bug & some email issue I was having was a deal breaker.