Currently Being ModeratedOct 3, 2012 6:10 PM (in response to alr135)
I would not invest the money in a new battery. Liquid damage can wreak all sorts of havoc and it is not likely to be just the battery that is faulty. In fact the battery itself might be just fine; if the logic board is damaged it could be misreading the fault condition. Liquids will cause corrosion and resulting latent damage that may not be evident for months.
I wish I had better news for you. Just keep using the MacBook for as long as you can. The repairs you require are not economically justifiable.