This is our situation:

We have an android tablet that must run some stuffs for longer than one day (running videos, musics or other).

For this purpose we attached our tablet to an external battery which should keep it charged for the duration, otherwise it would discharge totally in some hours.

The problem

After android M, with the battery process changed, this is what is appening:

  • Phone is running at (for example) 80% battery
  • After one hour of running it is fully charged to 100%
  • The phone goes into a non-draining mode (for battery saving)
  • The external battery, without any effective drain, goes standby mode.
  • Even if the phone goes back to 99%, the external battery is standby mode and won't charge it


The phone discharges in some hours and the attached external battery is fully charged.

Is there any way to solve this problem? I would avoid creating an app that hardly drain battery every time it goes to 100% and stops at 99%.. but looks like the only way I found.


Actually we are intentionally ignoring that long-usages of the batteries reduces their life, at this moment it's not the point

Thanks all!

  • I would suggest rooting the phone and using this app Battery Charge Limit from Play Store. It can set limits to stop and start charging say for example 60% start charging and 90% stop charging. You can do away with external battery .For more details see XDA app thread. It doesn't trip safety net if you are using Magisk. Bonus, it's open source – beeshyams Sep 1 '18 at 11:30

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