Which phone are you using? For iPhone users, it is all done with the
Storage Memory. Recently I found some tricky solution from this site. pretty useful it was for me. http://mashtips.com/gadgets-extend-iphone-battery-and-storage-memory/

Actually my mobile battery is draining very fast even i am not using my mobile just except accepting the calls on my phone
Even im closing all the applications properly im fully charging my

Does the phone usually gets hot before the battery runs down?

Try changing the battery, maybe the battery cell is weak.

Let me know what happens after changing the battery, so that I might direct you further.

Take care.