On Oct 4, 2005, at 6:55 PM, Brian Stevens wrote:

> Now I"m worried. If you find a cause (or many a posted  
> manufacturer's defect), please repost.


It usually is from overextended use of the batteries beyond their  
intended life span.  Or, sometimes a manufacturing defect.  Having  
dealt with many large commercial UPS systems, you begin to understand  
why they are encased tightly inside a metal shell.  Hopefully, that  
shell will contain the batteries swelling, which can be extensive. I  
have seen entire metal cases ripped apart by the swelling.

~ steve