I’ve got a 2G iPod Touch. It’s 22 months old. I had been running OS3 on it ever since OS3 was released and my battery life has been quite good. I’d be able to go several days before needing a charge. That all changed immediately following my updating to iOS 4. I was shocked at how quickly my battery lost its charge. I’d notice in the evening that I had 75% charge and in the morning it would be almost nothing. I never completely shut down my iPod but let it sleep instead. I also noticed that startup time took nearly 35 seconds where in OS3 it was more like 15 seconds to startup.
I began to research this issue and discovered a lot of other people voicing similar complaints with iPod’s and iPhones that had been upgraded to iOS 4. And a check in the Apple Forums uneartherd numerous threads with many people also complaining about the greatly accelerated draining of the battery with iOS 4. Here is an excellent forum with extensive discussion on the battery life issue
Numerous suggestions were offered to improve the battery life. Some of the suggestions were…
- In Settings>Fetch New Data, turn Push off.
- In Settings> Wi-Fi, turn Wi-Fi off.
- Make sure you do not have multiple applications running.
- Sync and backup your iPod. Restore the iPod to factory settings by going to Settings>General>Reset. Re-sync to restore your apps.
Well, none of those suggestions helped improve my battery life. To clarify, if I don’t have Wi-Fi on, my iPod becomes pretty useless for the things that I use it for so turning Wi-Fi off was no solution. Same with turning Push off.
The point is this: with no change in my usage pattern, my battery life plummeted with the installation of iOS4 leading me to conclude that there is something inherent with iOS 4 causing my iPod to suddenly suck battery power. It might be as simple as this… here is what I’ve learned about iOS4 compared to iOS3; iOS4 has a persistent Wi-Fi mode which means that prior to iOS4, Wi-Fi turned itself off when the iPod Touch was locked. Not so with iOS4… Wi-Fi remains on even when your iPod is locked so that may explain my precipitous drop in battery life. I haven’t had enough time to investigate this further but in the coming days I will try to make sure I turn Wi-Fi off wen I absolutely don’t need it to see it helps. It certainly should because Wi-Fi definitely will use more power than not having it on in the first place. If that turns out to be the main reason, what a pain in the butt it will be to always have to turn Wi-Fi off when not needed in order to save battery life compared to pre-iOS 4 days.
I felt that downgrading to iOS3 would be the most logical thing to do but when I called Apple Support to inquire about this I was told that Apple does not directly provide a way to downgrade to a prior OS. The tech implied that it was possible to do via an unsupported Apple technique but I have researched and concluded that I don’t want to attempt that myself. If you search for it on Google, you’ll find tutorials explaining how to do it but there is some risk that you’ll mess up your firmware and you may not have a positive result. I’d rather not attempt that, your mileage may vary.
I have AppleCare so that leaves me with about 2 months of AppleCare extended warranty coverage. I decided to walk my iPod to the Apple Store near me. Once there the Genius ran some diagnostics on my iPod and concluded that the battery itself was nearing the end of its useful life. I realize that Li-Ion batteries have a limited lifespan that diminishes according to how many charge cycles it has gone through but I just wasn’t completely buying his conclusion since my battery had been holding a charge very well and it was only after upgrading to iOS 4 that the accelerated battery drain took place. The Genius on the other hand smirked at me and told me that my battery was 2 years old and was shot. He felt it was merely a coincidence that my battery life seemed to be less with the iOS4 upgrade. He recommended I replace the iPod and since I was under AppleCare I went with that option.
It’s a fact that eventually my battery will die completely so at least I’ve got a newer battery. After one last sync with my computer and Mobile Me, I handed over the nearly 2 year old iPod 2G and received a new replacement (still 2G though.) That’s a great reason to have AppleCare since it would have cost around $80 to have Apple to replace the battery. The peace of mind that comes with having AppleCare, for me, makes it a good thing to do. And I’ve still got 2 months left so if this doesn’t fix my battery drainage issue, I can go right back to Apple within the next 2 months and pursue this further.
Has it solved the battery drain issue? I don’t know yet. I’ll know the answer to that in a few days and will follow up with an update to this post. In the meantime, I’d like to hear your experiences with iOS 4 and your iPod and iPhones. Have you noticed any difference in battery usage since you upgraded to iOS4?