Battery level indicator not working correctly? Solution:

If you encounter a situation when your laptop's battery level indicator at the bottom right of screen shows sufficient battery, but suddenly it gets hibernated without saying critical battery, then there might be a problem in your battery level indicator.

• Mostly, when you restart the computer, the problem vanishes away.
• If it does not, then you just have to calibrate your battery by following few steps:-

1. Charge your laptop’s battery to full — that is 100%.
2. Let the battery rest for at least two hours, leaving the computer plugged in. This will ensure that the battery is cool and not still hot from the charging process. You are free to use your computer normally while it is plugged in.
3. Go into your computer’s power management settings and set it to automatically sleep or hibernate at 5% battery. 
4. Pull the power plug and let your computer discharge until it automatically sleeps or hibernates. You can keep using your computer normally while it happens.                                                      (Note: If you want to calibrate the battery while you aren’t using the computer, be sure your computer isn’t set to automatically sleep, hibernate, or turn its display off while idle. If your computer automatically enters power-saving mode while you’re away, it will save power and won’t discharge properly.)
5. After it automatically shuts down, then let it rest for 5 hours or more.
6. Plug it back into the outlet and charge it back upto 100%. You can keep using your computer normally.
7. Change your power management settings back to normal values