Suspected battery drainage,Mitsubishi FTO?

[scarfacetm1984]

After installing new alternator belt,recon alternator and battery everything was ok,until couple days ago,battery went dead.gave it a jump start,alternator charged the battery and car was starting ok until same happened,battery died and all you can hear is clicking on the start,also notices water leaking from the battery's hole.Also noticed battery cable clamps touching the bonnet,so isolated it too and gave a jump start yesterday.was starting car every couple hours until today car ain't starting again,just clicking sound.Bare in mind car just stands and aint doing any mileage.cheers
P.S All electrics seems to work fine when car jump started and when battery charged by alternator