Battery full charge, it takes 30 minutes to hold time

I have a Galaxy S5 with me. I didn’t have any issues with it, one day after charging it, left it for 30 minutes and battery is almost drained. I didn’t even use the phone, I left it in my room. I tried to delete some applications but that didn’t work also. Can you tell me what are the best ways to resolve this issue? Can you provide me alternative solutions to do this? What are the possible causes of this problem? Can you guide me with this? Thank you!
