Uninterruptible Power Supply (UPS) for Lights

I've been experiencing a lot of short power outages lately; nothing long lasting, mostly less than 2-3 minutes then the power returns...sometimes it's several 15 second outages for that period of time. However this is enough to disrupt my CMH and cause magnetic ballast to attempt numerous restarts. And as you know, hot restarts do not readily occur with CMH or HPS bulbs.

In order to avoid the restart problem, I'm thinking of attaching a UPS to my lighting system (250 w bulb & ballast) - the computer fans could be connected to the UPS, but the centrifugal fan does not.

I've seen several threads stating that a UPS for HIDs would be expensive for the size necessary, but I think they are referring to a system that would keep the lights up and running for hours. Since I'm looking for only several minutes, I think a sub-$300 UPS would work. Newegg is selling a 1500 VA - 900 watt system for $180.

Can someone tell me if this would work? How long would a 1500 VA UPS keep my lights alive?

The alternative is to buy a hot-start prevention controller, but the affordable ones will only keep the system off for 15 minutes and I've read that some ballasts need as long as 30 minutes to cool down.

Thanks for your help.

250 watt ballast would do find with a 900 watt ups.

these things can be tricky to size due to all kinds of shit, i'm not so sure on. i try and size these all the time for work.

but regardless it will work for what you need.