Originally Posted by svHyLyte
Old batteries develop internal shorts that generate a fair amount of heat and cook-off electrolyte. Try reversing the order of the batteries and doing an equalization cycle. That may give you a bit more time but it may simply be time to replace the batteries. I now rotate the order of our batteries about once every 6 months which, supposedly, will give them a somewhat longer life span.
The batteries are brand new...4 months old to be exact.
I will, however, rotate them next month if the fluid is low again and see what is going on.