How can I increase battery life with iOS 4?

Question

Since I upgraded to iOS 4 on my iPod touch second generation my battery life is draining very fast. Is there anything I can do to help with that?

Answer 1

• Restart the iPhone (press and hold Home and the top button simultaneously till you see the slider to turn it off, and then slide the slider. Once off, press and hold the top button to turn it back on)
• Turn off Bluetooth (Settings > General > Bluetooth) if you're not using it.
• Turn off the WiFi option "Ask to join networks" (Settings > WiFi) to keep the WiFi radio from constantly scanning for new networks when you're not connected. It will still remember and auto-connect to networks that you've connected to before, but you'll have to manually connect to any new networks.
• Turn "auto-brightness" off (Settings > Brightness) and set the brightness level lower. I would only do this as a last resort if nothing else seems to work.
• Let the battery run all the way down to zero (i.e. let the phone run till it won't turn on anymore), and then recharge it all the way to full.

Answer 2

In addition to @kingbee's good suggestions, you can also shut off locations so the iPhone isn't constantly updating its GPS info.

In Spotlight Search, you have 10 settings to choose from that spotlight will index on your phone. The fewer you choose, the better. Just choose the key information types you want to index for searching and uncheck the rest.

In addition to turning off "ask to join any networks", I turn wifi off completely choosing to launch it only when I want to use it. If you leave it on, it will automatically scan for new networks which consumes more battery resources.