Battery drain

[AC Question]

dear,sir/madame

My name is Alex and Recently, i am experienceing battery drain so fast. i bought another battery to make sure. But still no change at all.

When the battery percent reaches 30% in 2 seconds it will be 15%. after it reaches 15%, every 3 second it drains 1% of battery.

My phone is Samsung Grand DUOS
i didnt do any update or what so ever. i try to put my brightness down, turn off mobile data,WIFI,location service etc. But still no change of the Drainage problem. should i Reset my Phone? or any other way?
Please help me solve this problem, i would appreciate it

 

[B. Diddy]

Welcome to Android Central! First thing to try is to unmount your external microSD card (in Settings>Storage), removing it, and rebooting. If there's a corrupt file on the SD card, or the card itself is corrupt, that can cause significant battery drain (often due to the Media Scanner getting hung up on the corrupt file).

If that doesn't help, then try booting into Recovery Mode and wiping the system cache partition, which won't erase any personal data. Follow the steps in this video, but at around 1:15, make sure you select Wipe Cache Partition instead of Wipe Data/Factory Reset. Then select Reboot System Now.

https://www.youtube.com/watch?v=KFn-dyjS-KA