keeps restarting and dies when charger is disconnected post spill

I recently spilt milk on my MacBook pro 15" A1398 I immediately took charger off opened up and disconnected battery and began a complete tear down and clean. The only spill indicator that was red was one of the battery's. There was not much milk inside but I got everything cleaned up with rubbing alcohol and canned air. I put everything back together after letting it sit for a few days just to make sure every drop of moisture was gone. I went to turn on and nothing so I plugged in and it started with the chime and the black screen with white apple logo. It just kept doing this so I did disc repair and now I can get it to boot but it will shut down on its own after a few minutes and if I unplug the charger it dies immediately even though the battery currently says 92% and said 54% when I first got it to boot up. Do I need a new battery or is there some fixes that I can try? I am pretty technically advanced so repairs are not an issue if I need to do any... Just not a very educated mac person yet. Thanks for all of your help in advance...