How to completely drain iPhone 4 battery?

joethomas675 wrote:

So the phone will stay like this indefinately? It is basically the last thing to try (before visiting apple, which is not ideal in my situation) to get my phone to reboot successfully.

If you totally deplete a lithium battery it will die permanently. So the iPhone doesn't let that happen.The phone will shut off and remove all power when the battery reaches a certain minimum state of charge. That point is called 0%, but there is actually some charge still on the battery. It will monitor the buttons, but there is nothing else running on the phone in this state. Apple suggests doing this on a monthly basis, but that is to recalibrate the battery gauge, not for the battery itself or for any other purpose.

a) I would listen to the people who seem to know a lot about lithium batteries when they advise you not to drain it completely

b) Your only option to drain power once you reach the point that you have mentioned, is to keep hitting the power button. The 'please recharge your battery' symbol that appears is the only remaining function left on the phone at this point, and the only way to trigger it is to hit the power button. It is possible to drain the battery to the point where it will no longer display this symbol, I have done it before. I cannot say whether or not that meant that the battery was completely drained, there is no way to tell. Doing this did not appear to have any adverse affect on battery my life.

KiltedTim wrote:

Why would you want to do this at all?

Because Apple tells you to do it once a month in their battery tips?

And if you never do it eventually your battery gauge will get confused, and shut off the phone at 30% or higher.

iOS will not let you run the battery all the way down. It will shut off with enough charge in the battery to protect memory AND to protect the battery from damage due to deep discharge. If you wait until it shuts off, then leave it unused for a week or two you may get the battery to go completely dead, but that will damage the battery.

Open as many apps as possible at the same time. Switch on bluetooth. Switch on push notifications. Watch HD YouTube videos at the same time.

Bluetooth won't make any significant difference. Open apps won't make any difference unless they actively update and use data doing it. Push notifications won't use power unless you actively receive notifications. YouTube is good advice. And Interactive games are a good battery drainer. And turn on the flashlight.

Completely drainging a lithium battery will almost inevitably completely ruin it. Lithium cells simply do not recover from a true, 100% discharged state.

You could have a battery issue, a charging circuit issue or some other hardware issue. At this point, you are really doing yourself a disservice by not visiting an Apple Store. Take it in and let them diagnose it for you - the testing and assessment are free of charge.

Or continue to try random fixes and potential do even more harm then good.

Michael Black wrote:

Completely drainging a lithium battery will almost inevitably completely ruin it. Lithium cells simply do not recover from a true, 100% discharged state.

Please look at my message 3 above yours.

Lawrence Finch wrote:

Michael Black wrote:

Completely drainging a lithium battery will almost inevitably completely ruin it. Lithium cells simply do not recover from a true, 100% discharged state.

Please look at my message 3 above yours.

I saw it, but people have been known to try silly things like run it down to autoshut off, then let it sit for a week or more to "fully drain" the battery. It will continue to auto-oxidize and loose charge just sitting like that, so can potentially be reduced to zero charge, but that will also destroy it.

My point was that is the very reason smart Lithium devices have an auto-shutoff feature in the first place, so the device will go off with a safe remaining charge, and one would then (hopefully) have the sense to plug it in and charge it. All smart Lithium devices have an auto-shutoff feauter built in, even Lithium powered electric toothbrushes.