So what's the deal with "usage"?

I don't use my iPhone 3G much. The main reason is that I already own an iPod Touch 1G, which I use for apps/games, Safari surfing, music, mail etc. I only use the iPhone for those things when I leave home, which I don't do all that often because I'm self-employed and work out of my home office/studio. So, when I'm not talking or texting, the iPhone just sits there on standby in the dock, charging.

Since the battery is very fresh (1 month old) and I rarely use the phone, I usually get good standby times. Best I've seen so far is 4 days on a single charge, and I still had about 1/3 power left. So now after installing 2.1 which supposedly gives better battery life, I thought I'd take stab at checking whether Apple's claim of "250 hours standby" was anywhere near true. So I installed 2.1, took the iPhone out of the charger, put it on the nightstand and went to bed. Woke up in the morning, checked the iPhone and... battery was down to 50%. Huh??

So then I went into Settings/Usage and found this:

Usage 10 Hours, 19 Minutes
Standby 12 Hours, 35 Minutes

TEN HOURS of "usage"? Please! 3G is off. Bluetooth is off. Location Services is off. Fetch is off. Push is off. Screen brightness is down to the lowest possible setting. This is one of the least "used" iPhones on planet Earth.

What is this voodoo crap? Is there some application running in the background, and if so, what gives it the nerve to draw power, and why is this happening with 2.1 when it never happened with 2.0.X, where my "Usage" readout used to be a few minutes? Do apps not really quit when I exit them? Can someone explain to me how I'm able to accumulate 10+ hours of iPhone "usage" while both myself and the iPhone have been sleeping for 10 hours?

 

Yeah, I did that after a recharge this morning and now it shows 2 minutes of usage and 2 hours of standby, but the thing is you shouldn't have to reboot like a madman every time you've used an application just to be on the safe side.

 

Yeah, admittedly WiFi was on, that's the one thing I've never disabled, but it never sucked too much power before 2.1...

I bet there's some secret debug mode task manager somewhere that could be used to identify the culprit... who knows, maybe the culprit is that crash-prone thingy called Safari.

Until then I'll try to remember to hold down the Home button for 10 seconds every time I've used the phone. Apparently this kills all running apps.