[X4U] OT: Belkin UPS

[Neil]

I have a Belkin 720VA UPS.  My dual G5 is connected to it.  The UPS should
be able to power my Mac for at least a few minutes, but it doesn't.  Even
when the power only goes out for a second, my Mac turns off.  There must be
a way to run the Mac off of the battery for at least a little while.  I
can't figure it out.  I can't find the manual.  We get power interruptions
here several times a month during the summer due to lightning.  Can anybody
here help me?  Thanks.