Originally Posted by
slave I reset phone, rooted it, set it up. This phone is getting 2 hours of screen on time, and dead in 6. I wonder if the battery is just bad, or are these phones this bad on 5.1.
5.1 is actually supposed to improve battery life, but ...
If the mobile signal is weak, the phone will use a lot of battery power. (if it's weak from the tower to the phone it's going to be weak from the phone to the tower, so the phone turns up the transmitter power - and that uses a lot of battery.)
Also, if the battery's been drained down to 5% or 10% regularly, after 17 months it may be way past time to replace it. (A lithium battery never dropped below 40% can last for years, but one dropped to almost dead all the time can be gone in 6 months.)
See
The Care and Feeding of Lithium Polymer Batteries.