The answer is in your post. also a comment. First the comment
IT IS NOT WATER (H2O). it is sulfuric acid. More on that later (H2S04)
Now you told us what the problem is "ended up adding some distilled water to each, bring it to just under a 1/4" from the top."
The correct fill level is 1/4" from the BOTTOM of the filler tube or split ring.
You over filled by about 1" give or take a bit depending on the battery
Look into the battery see the tube that you pour the water into 1/8 to 1/4" BELOW the bottom of the tube is the proper. many say to the bottom but give it an additional quarter inch to be safe.
Now
Little Willie Was a Scientist
little Willie is no more
For what he thought was H20
Was H2S04
(I can't believe I remember that from more years ago than I care to admit).
