[T2] Battery overflow on charge

[John Kolak]

I topped off a battery that had been sitting for a while to see if it
would hold a charge, filling to the bottom of the eye tubes as usual.

But this time after charging overnight all of the cells overflowed
leaving a nice acid mess on the garage floor. Now all the cells are
only about half an inch below the top of the filler holes.

Anyone have any idea why this happened?

John