More investigation will be needed. I suspect the battery was iffy before the water problem - it's quite common, the laptop I'm using now only works on adapter but I can live with that. Can you get any charge into the battery at all? Does it die as soon as the adapter is removed. What usually happens when the battery is duff is that it appears fully charged then discharges very quickly. The best check would be try another battery.
Finally, the battery is made of a number of cells. Usually only one fails. You may get a duff battery from ebay cheaply, and make one good one from two bad ones. You will need competency with a multimeter and soldering iron though.