[rescue] [Slightly OT] Smart-UPS 1400 Battery replacement

[rescue at sunhelp.org]

As far as I know, sealed lead-acid have a case that can 
put up with some pressure from gases produced during 
charging unlike the open lead-acid.  Otherwise, they are 
similar.
> Ok, I think I'm now truly confused.  I know of three types of batteries
> involved, Lead Acid, the old type that you have to add water to, Sealed
> Lead Acid, what I see in cars and upses, and gell cells, which I've only
> seen once in a Mazda Miata, which was expensive, and hard to charge.  Are
> sealed lead acid batts gell cells?  If so why are SLA batteries cheapish
> compared to gell cells?
> 	Nick