When my Samsung S3 battery gets down to 20-15%, the phone becomes unusable. The signal goes completely and the phone screen starts flickering. As soon as that starts, I watch the battery go down from 20% to 1% and die within minutes.

I've only had the phone for 4 months, and it is still under warranty. But I don't want to send it away to be fixed and be phoneless if I can help it. The phone is running the latest software. And I have done antivirus checks and nothing seems to be the problem.

The battery lasts perfectly fine until it gets to around 20% - 15%. Any ideas on what I can do to stop it from happening? Is it the battery or the phone itself?


That's really not normal. The phone should behave completely normally right up to the point it turns itself off.

Since it's still under warranty, you should make a warranty claim. Trying to fix it yourself (or taking it to someone else to fix) will void the warranty, and might not fix the problem, which would leave you worse off than you started.

From what you've described it's not possible to tell where the source of the fault is. If you have a friend with an S3 you could borrow, you could try their battery in your phone to see what difference that makes; but if you make a warranty claim, they'll likely want to test both the phone and the battery, even if you think you've isolated the cause yourself.


You Need to fully drain you devices battery until it turns off by itself at then plug it in the outlet and leave it overnight.


Battery needs to be calibrated especially if you are not charging the battery to a full 100%.


  • Charge your battery to 100% at least a week :)
  • Ample Power Company suggests:

    Conditioning Batteries

    How do batteries that are only four months old die? Perhaps they weren't broken in properly; maybe they sat deeply discharged for a few days or more; perhaps they were allowed to self-discharge. There's plenty of ways to murder batteries.

    All batteries that refuse to accept a charge are not necessarily ready for the scrap heap. Often, a deep discharge followed by a slow charge will recover lost capacity and charge acceptance.

  • 1
    Please cite your sources. Copying content from others without providing attribution is not appropriate. – eldarerathis Apr 4 '14 at 3:09
  • From my reading on Battery University between 40 - 80% charge is the sweet spot for LiOn batteries. They 'prefer' not to be fully discharged, and definitely not fully topped up and left plugged in. IIRC their staff leave them to 40 and charge up to 80%. The battery stats can be calibrated with apps if the device is rooted. – RossC Apr 4 '14 at 11:40
  • Sorry I forgot to post the link(source)... thanks for the edit... – dicenice Apr 10 '14 at 3:34

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