I updated yesterday to OS 4 on my 3GS and now my battery life is draining much quicker now. After limited use my battery level after 6 hrs is 40% when it used to be around 80%. Anyone else experiencing this problem?
Try draining your battery to the point your iPhone shuts down. Let it charge up to 100%. Keep it plugged in for another hour or so. See if battery life doesn't improve. It should.
My battery life has been great, possibly even better, since iOS 4 (3GS). Hope everything works out for you.
Mine seemed to be drain g faster than before but I then did a fresh restore as opposed to my restore from backup due to edge/3G connections issues and now the battery seems to be doing much better.
I've noticed an improvement since my upgrade. Nothing major, perhaps and extra 30 mins but it's better than nothing!
I've noticed an improvement in battery life. You need to condition your battery and restart your phone at least once every week.