battery moniter problem.

[Kj Wilson]

My phone battery moniter doesn't show a full charge & it's behavior matches what it thinks the charge is. This started about 2 1/2 months ago and it wouldn't show above 76% even after a full night's charge with the phone off. When the battery is placed in a different phone it shows a full charge. Any battery I put into my phone still wouldn't go above 76%. As time has gone by, the charge percentage has gotten lower and lower - today it's at 31% and won't go any higher. I've tried other android monitoring app, but they all agreed with what the built in moniter says. It didn't do this before I did the upgrade to android 4.1.2. Don't see any big drains on the battery, and power saving mode is on. Any ideas?