Well like everyone out there I want my iPhone battery to last forever – i unfortunately upgraded to firmware 3.1.3 and while I dont need a baseband unlock because my phone isn’t locked, I did want a jailbreak. All this aside, I found that as soon as I had upgraded, my battery life was a quarter worse than before.
I used to get pretty much 2 days use out of a full charge – I dont use the phone loads, just normal texting, a few phone calls and a bit of facebook / twittering, but after the 3.1.3 firmware upgrade, I immediately found I was getting only a days worth of battery life 🙁
Wasn’t happy especially as apple stopped me from downgrading to 3.1.2 which was nice and lovely.
So to help me get the best of what I had I made 2 changes which made a big difference and have resulted in me getting my 2 days usage back, and maybe even a bit more.
1: Disable location services – Go into settings > general, and change location services to off.
This does mean you no longer have your GPS active, but if you like me only use this infrequently, i’d rather switch it on in the odd occasion I do use it, than have it sucking my battery away.
2: Disable wi-fi scanning – Go into settings > wi-fi and change Ask to Join Networks to off. This means that rather than constantly scanning for available wi-fi networks, it will only use the ones you have pre-configured. Should you want to connect to a new network, you can either switch this back on or go back into settings > wi-fi and pick it from the list or add it manually. Again this saves loads of battery time as the wi-fi is not scanning.
These 2 simple tips made a big difference to mine and a few friends iPhone life, hope it helps you too.