On Sat, 10 Mar 2007 10:14:47 GMT, Ron Hardin
wrote:

Has anybody tried getting longer run times from UPS's by plugging
one UPS into another?

Power goess off, the first UPS goes on batteries, and runs everything.
When it quits, the second UPS senses it and goes on batteries, and
runs the computer.

And so indefinitely if you add more UPSs to get more runtime.

It seems it me it would work except possibly :

(1)The UPSs might not like the non-sinewave output of the first UPS, and
(2)I don't know what kind of current they draw if they decide to
recharge their batteries from an outer UPS. (This would suggest it's
wise to unplug the outer UPS when the power goes off so nobody
tries to recharge.)

Why not just take the battery out of the 2nd one and put it in
parallel with the battery in the first one? It would be more
efficient.