UPS and Time to End

We lost power at one of our sites last Saturday. I've been on the phone with
IBM attempting to find how how long it takes to go through a powerdown
cycle. The reason for the question to to determine how much longevity we
need in our UPS battery time.

What I have found out so far is the following:

1) The UPS is running the system until the QUPSDLYTIM passes, in our
case 300 seconds, or 5 minutes.

2) A PWRDWNSYS *IMMED command is given at the end of the 300 seconds.
How long that takes depends on a number of things - and there lies the
question.

3) If there is a job that won't end, the system waits for as long as
the QPWRDWNLMT is set for. In our case, 900 seconds or 15 minutes.

4) When the system goes down, and comes back up again (automatically)
if there is another power outage, we are in the same situation as we were at
step one, only now we are missing the battery power that was there when we
started.

So, what do YOU do? How do you come to the determination of needed battery
time? Do you just want to handle one time through, or more? At our home
office we have a huge UPS backed up with a generator - so the problem isn't
here. At our remote sites is where we have the problem.

TIA for your input,

Dave