(ET) speaking of weeping batteries…..

[tb <tbamc gbta net>]

I picked up a couple of used Trojans last year, to join the other 4 old 
U.S. Batteries.  The Trojans will charge up to 6.4v or so while the others 
are closer to 6.3 after a full charge.

I've noticed that the Trojans will almost always have some battery acid 
scattered over the tops after charging, while the others never do. 
The water level is slightly below the rings.

Haven't ever been around to watch during the charging, but wondered about 
your thoughts on this.  Are the Trojans bubbling more/more vigorously 
because they're fully charged sooner, and that's escaping?  Do their cell 
caps release more vapor--purposely, or incorrectly?   Defective batteries 
(the reason they were cheap)?

I've never loosened caps when I charge--just open the tractor 
compartments.  Should I?

Thanks.

Thon