I bought a first-gen iPhone a few weeks ago from a friend who had upgraded to the new model. Immediately I was dismayed by abysmal battery performance. Overnight the device would go from a 100% charge down to a 30% charge. Sometimes it would completely drain overnight just sitting idle on my nightstand.
Apple suggests a number of things to improve iPhone battery life, but it took a few days worth of careful experimentation to determine what exactly on that list was killing my iPhone. Turns out its two main things…
1) I live in a very low-coverage area, and some spots in my house the iPhone will ping-pong between “No Service” and getting service. Leaving the iPhone in these spots kills the battery very quickly. I’ve found that the only way to have the iPhone survive the night is to leave it in a spot where it gets one bar of service steadily.
Apple suggests you turn on “airplane mode” in these situations. Excuse me? I’ve had numerous other GSM cell phones over the years in this house and none of those drained themselves to death when they ping-ponged between service. The N-Gage would go for 4-5 days… Sony Ericsson P800 would go for 3 days… Panasonic G50 would go for 4 days… and most recently, my Nokia 6013 would go an entire week flipping between “No Service” and getting service. The polling frequency on the iPhone must be far greater than these other devices.
Actually, I don’t even care about receiving cell phone calls while I’m at my house. Why can’t I tell the iPhone, “if you’re within range of the wifi access point named XYZ, disable cell service”?
2) Fetching my email over wifi kills the battery. Even if I leave the iPhone in a spot where it gets service, if I enable fetch mode the poor thing won’t survive the night. This appears to drain the battery even faster than spotty cell reception.
Everything else about the iPhone so far I think is pretty dang awesome (and useful), but the battery life problems trump the utility of the device. I’d love to be able to leave the thing laying around my house wherever and checking my email every 15 minutes, but alas, I can’t do that with it.
When my first-gen iPhone was jailbroken on 1.14, I had a utility called “System Information” that showed all the processes that were running and allowed you to kill them. I found that even when I exited programs like Safari and the iPod, they were still running. When I killed them, my battery lasted a lot longer.
Also 2.0.2 seems to have *way* helped out with battery life.