My phone got wet...low battery life now...will a new battery help?

I have a Samsung Alias 2. I went swimming with it a few weeks ago. Dried it out and it works, only thing is the keyboard doesn't show up any more and the battery dies after 2 - 6 hours. I've had the phone for a while now so i've memorized where the keys are. Will a new battery fix my low life battery problem or is it the phone that wastes energy fast? Also the screen doesn't shut off anymore when it's in my pocket so maybe thats using extra power causing the phone to die quicker?