I have 2 deep cyle batteries on my trolling motor. It's a 24v system and has a Guest 2 bank 4amp onboard charger. I checked the water in the two deep cycle and one of the deep cycle batteries was fine. The one that wasn't fine took 3/4 of a gallon of water. The battery is less than a year old. I'm wondering what would cause this one battery to use so much water. Could something have gone wrong with the internal plates of the battery and caused my charger not to turn off and it just burned all the water out trying to charge it? I keep the batteries in well secured battery boxes and then I have those silicone vibration dampners under the battery to prevent damage. Any thoughts on this theory would be appreciated. Also, another thought, could this be an electronics issue with the trolling motor causing some kind of shorting or drain that burns the water? There is no battery acid in the battery box so I don't think there is a cracked case.