Several users have reported diminished battery life under iPhone OS 2.2. A pair of Apple Discussion threads–one with 59 replies (“iPhone Update 2.2 Drastically Reduces Battery Life”), the other with 78 (“Battery drain since upgrading to 2.2″)–chronicle the issue. Sample reports include:
- “Yesterday, I went all day (12 hours that is) without recharging. Last night I upgraded to 2.2. Today, after being off the charger for 4 hours, it is down to 20%.”
- “[...] happens with both iPhones we have after 2.2 upgrade. When we went to bed, iPhones were fully charged, and in the morning, 10% of the battery was left.”
- “Same problems here. I have one me.com account and one exchange account – both set to push. Power drain after about 6 hours. This is not good for a mobile device. Blackberry went days without recharge.”
- “I updated yesterday night to 2.2 and left the iphone charge over night. I took the phone this morning and went to work. I did not use it until mid day when I went for lunch. I wanted to check my emails and saw the battery was fully empty. I could not use it anymore.”
One fix that has proven successful for some users experiencing this problem: delete then re-establish any push-capable accounts (Exchange, MobileMe). Failing that, delete and re-establish all email accounts.
We’ve published a number of potential battery-life boosters, including:
Drain the battery completely Use your iPhone until the battery dies completely (indicated by a battery icon appearing on the screen when the sleep/wake button is pressed), then fully recharge the device. It appears that the full discharge may reset circuitry that prevents a full charge from occurring, despite iconic indication of a full charge.
Turn off location services It appears that the Maps application and some third-party applications that use GPS functionality fail to power down the necessary hardware components when they are no longer in use. Navigate to Settings > General > Location Services and turn these services off when you are not using Maps or another location-enabled app.
Turn off Push then restart The iPhone 3G’s Push functionality for Exchange and MobileMe accounts can destroy battery life. Turn this option off in “Settings” then restart your iPhone by powering it off then on.
Restore the iPhone with original settings Launch iTunes and select the second option in the “Version” section on the Summary page for your iPhone. This restore process will erase your iPhone software and data, including all settings, which can be restored later via iTunes.
You might also want to check out special report on increasing battery life.