I checked a lot of forums, like a lot, but no one had my exact problem. I have an ASUS Tablet with Android 4.2.2 and the battery icon in the notification bar has a question mark in it. At least when it turns on cause ocasionally it crashes on boot and reboots itself before even reaching the lockscreen. Anyways, when I'm lucky and it turns on, it eventually crashes and reboots after a few minutes. If it is on and I try to get to the battery settings, it crashes and reboots. I didn't manage to get to the battery to check the contact, like most forums say, but I don't think it's the case as it's getting juice from it to turn on...

I tried reseting it by the way.

  • Does the tablet work while it is connected to a charger? As your tablet is older most likely the battery (and/or the battery controller) is defect -> hardware defect. – Robert Sep 6 '19 at 8:34
  • @Robert No..not really. When it's connected to a charger it just displays a battery with a question mark in it instead of the charging icon, but it does sometimes turn on without a charger. Very strange... – stfn Sep 6 '19 at 9:11
  • Ok, then your battery is definitely dead. You have to replace the battery (e.g. in a repair shop) or buy a new tablet. – Robert Sep 6 '19 at 9:14
  • @Robert I understand...but why does it turn on when it's not connected to a charger? – stfn Sep 6 '19 at 9:15
  • Looks like the OS fails to get the battery info from its sensor, thus returning a question mark. Perhaps the battery is not totally dead yet, but it's already broken until the OS can't even recognize its value. – Andrew T. Sep 6 '19 at 15:10

There can be three reasons for this:

  1. Your battery is dead or the Battery Status Indicator (BSI) pin on your battery is faulty. In either case, you have to replace the battery.

  2. The BSI pin head on your phone hardware is faulty.

  3. The firmware on your phone has a bug, and is unable to properly read the battery charge.

The third one is very less likely. The second option is less likely, but in my case (a Samsung Galaxy On7), both 1 and 2 had occurred at the same time.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.