● Android - Kit-Kat (and above) battery discharging in less than a day
If your Android (running Android Kit-Kat or above) device's battery runs out before the end of the day or only last 1/2 day, here is a possible solution to fix it.
  1. Go to Settings ► Location.
  2. Check if the "Mode" is to "Battery Saving". If not, click on "Mode" and set it to "Battery Saving".
  3. If the above hasn't improved your Battery life,
    Go to Settings ► Privacy ► Privacy Guard
  4. Scroll down to "Google Play Services".
  5. Click on it and hold to get the settings for it.
  6. Then scroll down to the "Wake up" entry and from the drop down list, (on the right of "Wake up"), chose: "Denied".
  7. Restart your smartphone.
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I've seen it happening on a Samsung S3 with an AOKP Kit-Kat ROM, a Samsung S6 with a stock Lollipop ROM and on a Motorola Droid 4 running a Cyanogen 11