Actually, a typical battery filling device would stop filling when the water
reached the end of the tube. At least the one my grandfather had did.
In any case, liquid batteries are a dinosaur anyway, not worth the risk.

Doug

"Don White" wrote in message
...
In the 'good ole' days', before maintenance free car batteries...you would
fill until the water level touched the bottom of the filler tube. It was
easy too see when this happened...that surface tension thing...