As for the problem you are facing with boiling, it is hard for even the dumb to overfill a battery with proper battery handeling trainig, and an auto water system. I would be curious to know a few things about your batts- what is the a/h rating but more inportanly the finish rate on the battery and charger? Are the smart chargers set at a 5 cycle equalize or has that been shuffled? I ran into this problem with a large fleet a few years ago and it ended up being the chargers were not finishing the charges at the rate specified.