Battery Dying Around 50-70%

[Apples Captor]

My phone is on 24/7 and lately it's been annoyingly dying around 50-70% as mentioned in the title, no low battery warnings or anything, just simply turns off and can't be turned back on unless I plug it into the charger, and sometimes the phone gets fairly warm, I assume that's a problem. I haven't downloaded anything for months upon months, I'm thinking of getting a new battery but I'd prefer to see if there's something I'm doing wrong before I spend money on a new battery.

EDIT: My phone just died on 99% and is now in an infinite loop trying to restart but dying at the "Samsung Galaxy S4" screen, I'm just gonna remove the battery until someone replies.

 

[B. Diddy]

Welcome to Android Central! A new battery would be the first thing I'd try. A quick way to confirm problems with your current battery is to place it flat on a table and try to spin it. If it spins freely, it's bulging in the middle, which is a bad sign. But not spinning doesn't rule it out.

 

[Apples Captor]

Well crap. It span like a top. Guess I need a new battery. At least I tried thanks for the help.