Check your iPhone battery for Self-Discharge
What is Lithium Battery self-discharge?
Some battery drain problems have been identified in the forum as batteries with electrical self-discharge, often caused by distortion of the internal lithium deposits during charging ('dendrites'), even though the Battery "Health" (capacity) is way above 80%.
How to check your device for internal battery discharge is very simple:
- Charge the device up to 100% (or as high as it will go) then remove the cable. Make a note of the charge %.
- Power off the phone completely - Powering the iPhone off and on but when you get to the slider, tap on the "iPhone Findable..." link and use the "Temporarily turn off Finding" option to disable Find My Network and avoid unnecessary battery drain while off.
- Leave the iPhone off for 8 hours or so, overnight if that is the most convenient.
- Power up the phone after this period and see what battery charge percentage shows. It should only have dropped 2 or 3 %, used to power it back up.
- If it has drained much more than that, like 10% or more, then an internal electrical self-discharge is suspected and it should be taken or sent in for a new battery. See: iPhone Battery & Power Repair. Important: Include a copy of this tip with the repair.
- The Apple Support App may not initiate a repair for batteries over 80% health so in that case contact Apple Support and explain the concept of self discharge as it seems that Apple don't teach it internally.
REMEMBER the phone or ipad must be POWERED OFF and OFF CHARGE with Find My Network OFF to do the test.
This is like blaming the engine for poor fuel economy when in fact you have a hole in the fuel tank.
Check yours!