Last night it rained and water got on the battery because I didn't realize the seal between the car and the back of the hood is loose. Today I opened the hood and got all the water off and let it evaporate for an hour and then jump started which went fine. Then I drove it to get some sealant to fix the leak and when I got in my car after getting sealant she wouldn't start again. I had someone help me jump it but when she started the voltmeter did not stop moving. My car was shaking and every time I hit the brake the needle went all the way down and then back up really fast. When I gave it some gas the needle went past 15. Eventually she just stalled when I rolled down the windows and when I jumped it again she did the same thing. Please tell me it's just a new battery. If there's a short somewhere where would it be and how would I fix it? For now my car is sitting in the middle of a Kmart parking lot.