i have an iphone 3g. it is on 3.1.2 and has worked fine until a few weeks ago. now the battery dies every 3-4 hours while in standby. i have tried everything. i have removed all of the apps but the ones you can't and it still dies. i have done all the rebooting i can think of. i have even changed the battery and it still dies fast.
so i was thinking of hitting the restore button in Itunes. i have not upgraded to 3.1.3. so will restoring make me upgrade to 3.1.3?????? can i re-jailbreak the phone with blackra1n???
or are there other ideas as to why my battery dies so fast. i will just sell the phone if i cant' fix it.
The 3G won't force you to install 3.1.3, only the 3GS. I would try a restore to 3.1.2 and see what happens. Do a fresh install of 3.1.2 and don't even jailbreak it for a day or half a day. See if the battery still drains as fast.
Download the 3.1.2 ipsw and do the Shift restore method, don't update to 3.1.3 via itunes as then any unlocking options are gone.
download the firmware you want to install so you have it on the computer then go into itunes and hold down the shift key while you click restore. You'll be able to browse to the firmware file you want to restore to instead of having apple just install the newest for you.