Why lumia 640 battery is draining fast?

[WPCentral Question]

Recently i bought lumia 640 at Amazon. I bought it because many reviewer had written its battery life is very good, but i found that battery is draining very fast even in idle state without active background apps. Phone heating very much. Before it i had used Nokia lumia 630 and it was amazing phone it never heated up and battery draining problem.

 

[Sedp23]

make sure bluetooth and nfc are both turned off if u arent using them. if u are still experiencing drain u probably a rogue couple apps sipping all ur battery i would try a hard reset and see if that helps

 

[Rose640]

If you're on the preview that's more or less a normal thing, but if you're still on the 8.1 then i suppose either you have a malfinctioning device or using bad 3rd party apps.
Cause my 640 used to hang up to 3days, seriously, there's even a SS in 640 subforum. So you should go and try to replace your device.