Jim Weir wrote:

Respectfully disagree. You take an OLD 25/35 ah aircraft battery and float it
at 13.4 for a week or so and it will burp acid. New ones will not, old ones
will. Been there, done that.

Respectfully disagree with your respectful disagreement...

If the voltage is 13.6V, then with caps off you get little specks of
acid splattered around.

If the voltage is 13.5V, then no splatter...

The splatter is caused by charging hard enough to evolve gas. As the gas
bubbles rise to the surface, they pop, causing the splatter, just like
a carbonated drink. At 13.5V, no bubbles, therefore no splatter...

MikeM