It's been a couple of weeks with the Extended Battery and I still can't make it through a whole day with a charge. I charge it every night while I'm asleep, and it's at 100% at 6:30am. By about 3:00pm, I'm around 40% and that's with minimal to moderate usage. Read about 20 emails. Check FB once or twice for about a minute or so. Check "Twitter" about five to ten times...each time less than a minute. No media (video, music, etc.) No games. (But oddly enough, when I do view a You Tube video or two, or play a game, or listen to Pandora, the battery does not seem to drop as quickly.)
I found a "Battery Graph" app, and today - for example - from 12:02 until 12:07 (five minutes) the battery dropped 10% (from 88% to 78%)!! During that time, I was not using the phone at all; it was simply on my office desk. Then from 1:07pm until 1:12, it went from 73% to 65%! Again, I was not using the phone. When I got home about 5:30 this evening, it was at 30%. I charged it up to 50% (which took until about 7:00pm). Now, at about 10:30pm, I'm at 20% (but I have been using it a lot tonight).
I have shut off everything I can think of (GPS, WiFi, etc.) I have no widgets updating on a regular basis. I have ATK set on "Crazy" and to 'kill' when the screen is off. Signal strength is very good - 95% of the time, I have full bars. I have the Battery Mode set on "Maximum Battery Saver".
When I check Battery Manager, my Display always is the biggest drainer - at least 50% or more. The next two are usually "Android System" (less than 10%) and "Cell Standby" (usually around 5%). I've set the brightness at 0%. (Yes...zero percent.) Screen timeout is set for 30 seconds, even though I usually turn the screen off manually.
What else can I do?