Bad battery?

[TheChief]

Either that or it needs calibrated. Used it the entire time it was unplugged. As you can see the level falls off quickly then slows down a ton. I used the phone just as much and did just as much stuff.

In as little as two hours the meter went from full to 23%.

 

[jerofld]

So your display was on for nearly 4.5 hours straight? Did you turn off autobrightness and set brightness low? Considering the huge amount of power the device is saying is being taken by the screen, I'm not surprised that it only lasted 4.5 hours.

 

[TheChief]

The display, although a power hog, is not the problem. In a perfect world a battery should have a slanted discharge rate. However in reality it does not. However it falls off way to quickly and then seems to discharge slowly.

 

[jerofld]

It looks like it levels off at 15%, which is when power saver kicks in. That's why I said what I did about auto brightness. Power saver force dims the screen. It also kills auto sync. So you might have an app that is constantly using data and keeping your device awake and using your data connection, draining the battery. Like that weather app I see in your notification bar. Or whatever that other app is in the notification bar.

Or you just need to reboot. Sometimes a rogue app just needs a phone reboot to get back in line.

Another thing that may cause incredible power loss is if you're rooted and you do a batch restore of apps + data from Titanium Backup. I did that recently and the phone worked fine the first day, then the next day I couldn't get 6 hours out of it. I wiped /system, /cache, and /data and manually rebuilt everything, battery was rock solid after that.

 

[TheChief]

It's not any apps, background data, etc. The display sucks up 80% of the battery. Everything else is using 20%.

Phone standby AKA background data was only using 4% the entire time the phone was unplugged.

How long do li-on batteries last?

 

[jerofld]

Don't always believe that page to be 100% accurate. I've been streaming music over my bluetooth headset for about 4 hours today. The battery chart doesn't even say that Bluetooth has used any battery. I've been using Google Talk, which uses background data, and it doesn't associate any power usage to that, either.

But to answer your question, I get about 16-20 hours with 8 of them being heavy use as a music player at work. It all depends on usage and settings. If you have your screen on a lot and have brightness up high or on auto brightness, expect your display to suck down a lot of juice. Especially if you have a big screen (4.3" or bigger)