Battery Calibration

There's no such thing as optimizing Apple's Lithium-ion batteries. Just turn it on.

Batteries - Apple

venomx92 wrote:

I have a 4s with iso 9.3.5

I let the phone power off by itself when it got to 10%

Then i connected the charger, and turned the phone off so it can charge without interruption,

How will i know when the charge is 100% ? Because the screen displayed a battery with red in it, now its gone off.

Take the phone off the charger whenever you need or want to. You don't have to wait until it gets to 100%. You can also leave it on the charger after it has completed charging. That won't hurt it either.

Yes, your phone is charging even though the screen is off.

The process of calibration was to calibrate the battery sensor, not the battery itself. It is no longer necessary or recommended. The article anypats linked to gives more details.

If your battery is draining quickly, it's probably because it's very old. No amount of "calibration" will fix that. You'll need to get it replaced.

Anyone that says it has helped is simply perceiving that it helped and didn't actually get any performance increase. If your iPhone is off and on the charger you will not get an indication that the charge is complete. Yes, it will have been charging but you won't know when it gets to 100%. As I said before though, don't worry about it and just turn it on.

venomx92 wrote:

Thanks anypats

I live in a low signal area, its usually on 1 bar.. this can drain the battery more than a high signal area ?

That will drain your battery faster than almost anything.