iPhone 3GS Battery Problem

Within the past couple weeks I’ve started to notice that the battery on my iPhone 3GS has been draining awfully fast for no reason. Prior to this latest issue, I’ve never had any problem with battery life. I charge my phone every night as I’ve done with every phone I’ve ever had whether it was completely dead or not, it’s just the most convenient time to charge it, plus it’s my alarm clock so I would hate for it to die over night. I know the iPhone’s are not known for their incredible battery life to begin with, but I’ve never had a problem before and could pull out at least 2 full days without a charge and moderate use, but over the past couple weeks I have been barely able to pull off 1 day on a single charge and I have no clue why.

I haven’t done anything different to the phone, I don’t recall installing any apps that would have caused this, yes my phone is Jailbroken, but I don’t run apps in the background, I pretty much only Jailbroke it so that I could use Lock Calendar to put my recent events on the lock screen (I hate having to click into the calendar to see what I have coming up). Sure I have Wifi, 3G and Push Notifications turned on, but I always have, so it’s nothing different. I even went so far as to restore the phone Saturday afternoon hoping that maybe it was just some glitch with the phone and a restore would fix the issue.

Before I did the restore though I had to make sure that the latest firmware version 3.1.3 had the ability to be Jailbroken and everything I read said that while it is able to be Jailbroken, if you don’t need to update the iPhone Dev Team recommended not updating. Now this is where I was torn, the release notes for 3.1.3 say that they address an issue with the battery meter going all funky and displaying the wrong percentage and not telling you exactly how much battery is really left. Now I’m not sure if this means that since the battery meter itself is going crazy that the phone bases it’s actual battery level on the meter, so if the meter says I only have 5% battery left, when in fact the phone has 80%, it will still shut off due to the information it’s receiving from the meter itself. And I also read that if you haven’t stored some hash information with Cydia you may not be able to jailbreak your phone in the future. So seeing as how my Cydia would crash on opening due to a corrupt repo download one day, I couldn’t have Cydia store that information for me, so I decided that was a good enough reason to restore to 3.1.2, for at least the time being.

Later I did some reading on how the 3.1.3. upgrade was working for everyone and I discovered that a lot of people were seeing slow downs and even worse battery life. I know that not everyone will have the same experience and these may not have all been 3GS experiences, but it was enough to keep me from upgrading to 3.1.3, but if this battery issue continues I feel like I’ll have no choice as it’s absolutely ridiculous that I unplug my phone at 5PM with 92% charge and by 8PM of almost no use it’s already at 50%. I have no desire to carry around my charger whenever I go out in hopes that I’ll have an outlet to plug my phone into, I already leave it charging at work, but this is really getting ridiculous.

Is anyone else experiencing similar issues? Did the update to 3.1.3 fix the issue? Are there any other fixes out there that I can try without having to update? I’ve already tried turning wifi off, but what’s the point of having a 3G phone if I need to turn the 3G off in order for the phone to function for a single day? I love my iPhone, but this is absolutely unacceptable.

Update: Phone is currently plugged in, I went to a few websites and the phone is now at 85%… I unplugged it and plugged it back in at it instantly jumped back up to 100%. Leave it to the Jesus phone to rise from the dead… seriously 3.1.3 might be in my immediate future despite the possible risks, this is ridiculous.

Update 2 (2/22/10): Looks like the culprit may be using an Exchange server to sync a Calendar. I don’t use Exchange for contacts or mail so those could also be the problem, but when I turn off my Google Calendar Sync Account (which uses exchange) the battery life seems to go back to what it was before. It’s only been about an hour, but so far it seems to be a huge improvement. (I think I spoke too soon). The only problem with this though is that I need that Calendar as it’s the one me and my girlfriend share so I have been using it for all of my appointments instead of the one native to the phone. So if anyone has a solution, please let me know.

Update 3 (2/23/10): The above account is everything that was happening yesterday, but after a full night plugged into the wall the phone seems to be alright this morning. I unplugged it from the wall at around 6am and it’s now 7:25am and I still have 100% battery. Wifi is turned on, 3G is turned on, the only thing that is not turned on is the Exchange Server connection to Google Calendar. I want to see how the battery does today without it on and I’ll turn it on later to see if that then causes the battery to drain. I just hope I didn’t jinx myself by posting this… we’ll see how it goes.