Randomly Dying 3GS Battery

Apple iPhone - Continuing Saga of the Randomly Dying 3GS Battery

I'm having with my 3GS. Back a few months ago, the phone would abruptly shut down - at anywhere from 35% to 80%. I tried running it down to recalibrate (but if it shuts down at 47%, is it really "run down"), letting it sit idle for a day (I got the shakes - it felt bad), and other tricks I read online.

I went to the Apple store two Saturdays ago, and I was told it was probably a software problem - and I should do a system restore.

Yesterday I did that - Got all my apps, music, contacts, photos synched and backed up, and did the restore. Felt good... got the looks of the apps and folders adjusted, and things seemed ok.

... Until the thing died at 68%.

I'm trying it again today - no charging while at work. So far I'm down to 84%, and would really like to see the thing go down to 20% or so.

Then I'll try actually using it to get the charge down (rather than letting it sit idle) and see what happens from there.

I read on a few boards that this is not an uncommon problem. If anyone has any other suggestions, I'm all ears.

iPhone Battery
It is not all that common on the 3 lists that I am on.

How old is your 3GS? They were released in June 2009. Since your 3GS could be getting near the end of the warranty and the Apple Care, I would do something about it now. If it is outside of warranty, they you will have to replace the battery.

I don't think that they recommend recalibration of the iPhone battery.

If you are having a problem after a reset, then it might be a hardware issue, or age. They do happen. But try the recalibration first. Or take it back in to the Apple Store, just back everything up before you go.

This is the procedure to recalibrate a Mac laptop battery. If you don't mind using some of your cellular data usage, then turn off WiFi and watch a NetFlix streaming movie, or listen to Pandora, until the iPhone shuts down. If you don't want to use your data usage, then do the same using WiFi. I believe the instructions say to leave the device for several hours, like 5 or more, in this state. Then charge the device fully. Disconnect and use the device. Watch when it shuts off again. If it does not give you better performance at this point, then I would take it into the Apple Store and tell them all that you have done, and if you can reference back to the earlier visit, do that.

Again, I don't think that they recommend recalibration for the iPhone battery, so I take no responsibility if you do.