More likely is that the water is hydrolized into hydrogen and oxygen that escape as gasses. THat's why every once in a while a battery explodes.

Newer batteries have calcium in the plates to minimize the hydrolization, but still a small amount of water sometimes needs to be replaced.

Retighten the wheel lugs after driving on them for a while? I knew that but I thought they were to be checked after 400 to 500 miles. I have found some to be loose after 500 miles so the theory is valid.

P E H