I did it many times when I was young and didn’t know any better. We would take the caps off and watch the electrolyte bubble. When it bubbled for a minute or so, we would disconnect the leads let it cool a minute or two and start over. Never did an overnight unsupervised charge. I’m surprised it didn’t boil dry or explode on you.

Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
Support those brave men/women who stand the "Thin Blue Line"! Hug a cop!
USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)