Another Battery Question

[bander68]

I woke up at 5am this morning with my usual alarm. My phone was on the charger, as always. The green light was on showing a full charge. I took it off, went and brushed my teeth and headed downstairs for some coffee. I poured the coffee, turned on the TV to watch the morning news. Looked down at my phone and the battery was at 82%. Wow, 5-10 minutes of non-activity, and it's already at 82...make that 81...make that 80 %. It's dropping as I watch it. Well, this is odd. I decide to reboot before I do anything with it. I reboot, sip some coffee, check out the weather forecast on the TV, then look back down and it's almost finished rebooting. The battery is now at 39%. !!!! What in the world is going on???
I plugged in a charger and got ready for my day. It charged about 30% over the course of the next hour. When I take it off the charger, it seems to be holding. I plug it into my car charger while I drive to work, and once I arrive I check and it's up to 84%. I go into work and stick it on another charger and log in here to ask about it.

I've barely used this thing today, and it's all over the place. My morning routine is like clockwork, and normally I'm around 80-90% by the time I get to my desk. Did I get a "false charge" overnight? Is my battery just crazy or dying? I haven't downloaded any new apps in quite a while. I have a a handful of games I play, but they're the same ones I've played for over a year. SongPop, BingoBash...

Any thoughts?
T-Mobile, S3 (not LTE), 4.3, unrooted, purchased new 20 months ago (August 2012).

 

[aml1025]

Did you check you battery monitor see what was using the most battery life at the time? (Settings > more > Battery). It's a useful place to start, although in your case it does seem like something more is going on too.

 

[bander68]

Did you check you battery monitor see what was using the most battery life at the time? (Settings > more > Battery). It's a useful place to start, although in your case it does seem like something more is going on too.

Yeah, I checked that. It said the usual - Screen at 41%. Everything else negligible. I keep the screen brightness down at about 15-20% on the slider. I have the timeout set at 1 minute, but that doesn't explain the extremely fast loss or the big drop when I rebooted.

 

[funkylogik]

Its maybe just the battery. Mine is about 2yrs old and just recently its acting all weird. My wife is getting an s3 tomorrow so im gona swap batterys for a day and see what happens