This morning and only this morning have I observed a bizarre battery drain issue on my iPhone 3G. Before I start, my iPhone 3G is less than one month old and I have the latest firmware 2.2.1 (5H11) and it normally lasts 3 days in between charge since I use it lightly. My settings are: No Push Email, 3G network enabled and allow location tracking. I have a few apps installed (FaceBook, Amazon, Skype, Fring, USAToday, Twitterific, Midomi, eBay, Loopt and Local Picks). In normal days, I would charge my iPhone every 2 to 3 days. My usage is light, check my email 3 times per day and listen to music for an average of 30 minutes per day.
This morning, I didn't even listen to music and did my usual email checking, news reading during my commute to work. I noticed Twitterific app crashed during launch. Thinking of nothing, I powered down the LCD and put it back into my jacket pocket. When I got to work, I noticed my iPhone was a little warm and I was at 75%. 15 minutes later, it showed 50% full. 10 minutes after that it was around 33% full. I'd give it a total of 2 hours since Twitterific app crashed before my iPhone 3G was down to 20% battery warning. Since I've got a full day to go and I knew something wasn't right, I rebooted the iPhone and turned off 3G network. That seemed to have stopped the madness and lasted a full day in red.
Something must have gone wrong when Twitterific failed to launch earlier today. I am not suggesting it was that app that caused the problem but somehow the iPhone was stuck in a mode in which it was running some crazy processing to drain my battery since that moment. While the LCD was turned off, the iPhone itself was busy draining energy. A reboot seemed to have fixed the issue.
The reboot seemed to have done the trick, I recharged my iPhone and now it looks like its normal. An hour after I undocked, it still shows 100% charged. I'll keep an eye on this and keep everyone posted here.
Some online references:
iPhone 3G Fully Charged to Dead in 4 Hours