I believe this has to do with venting hydrogen, I think that most modern
batteries have built in vents that can dissipate this, with out the hazard
of having the acid/water exposed.
"Jimbo" . wrote in message
...
This newsgroup has the greatest selection of experts on the web so I hope
you will excuse me for asking an off topic question about charging lead
acid
batteries.

Back in the early 60's when I worked in a service station I was taught to
remove the battery caps when charging a car battery so that's how I taught
my boys to do it. My son just finished his lift truck training course
and
they told him to leave the caps on. I checked a number of web sites and
they all say the same thing, leave the caps on.

My question is have I been doing it wrong for the last 50 years or at one
time was removing the caps a standard practice that has since been
considered unnecessay or unsafe?

Thanks in advance

Jimbo