How often are you able to return more than you take out, by at least 15%? Using all that water makes me wonder if the low cell is still heavily sulfated and you are having to do a lot of overcharge on the stronger cells to charge it. If you are losing water while only returning the amp hours used, you are recharging less and less each time. Out gassing takes extra amp hours away from those that charge the battery. A third of a gallon is something like 5500 watt hours (figure something like 350 amp hours) consumed that were not charging the battery, but were producing gas and lowering electrolyte level instead.
Jim
