iPhone 3GS Unique Battery issue

[wirelessprom]

I use my iPhone as an alarm. Normally, I have it at around 60-80% of battery left right when I go to bed. I'm having an issue with the battery only in the last few days, (perhaps after 3.1.2 firmware update), where the phone battery is being used up even during sleep. It seems like my phone wont switch over to the external power source. Like it's just using the top 1% of the battery over and over again. Why i'm having iPhone 3GS Unique battery issue? Any one has any idea about it? Please help me to resolve the above issue. Thanks.

[Dharmavira]

Did you try doing a hard reset (hold power and home button for approx. for 10 seconds should turn off) while it's plugged into the charger? Reception issues are probably the cause of most of the battery life issues on this site. I think you should try to do a Full Charge before bed.

[Sunny55]

When a battery overheats, it’s getting a runaway reaction that produces gas, causing expansion to occur inside the sealed battery. Put the device into DFU or Recovery Mode and do a restore in iTunes, it should detect it then. This expansion puts pressure on components, damaging them and eventually killing the iPhone.

[Dolf]

Push Notifications can be turned off from the Setting menu. This procedure can right a faulty battery indicator and eliminate applications that have hung or are otherwise improperly chewing battery. First open iTunes and connect your USB cord to your computer, but do not plug it into your iPhone. Then press and hold the home button on your phone while connecting the USB cord into your iPhone, while continuing to hold down the home button.