Backup Batteries (UPS)

Last month my power went out for about 3 hours, and if I had been growing I'd imagine my apartment would have started stinking up pretty badly so one thing I'm looking at is a UPS (uninterruptible power supply) to keep my fan/carbon filter going if/when it happens again, or any other alternative options people can think of.

This is the one I'm looking at right now:

1500VA/900W

I found this chart:

On a 900w UPS I should be able to get at least two hours out of my 45w fan, but I want to know if anyone has any first hand experience with this, or has any other ideas.

-- I still can't post links for some reason :/

I use UPS for my water pumps, I live out in the country and power goes out often unfortunately, the UPS keeps the pumps pumping. Luckily we aren't usually without power for long. I really should invest in a backup automatic generator but they are so damn expensive. Then I would need propane to run the thing too. But the UPS works great to keep the water pumping.

I use dc fans for ventilation. They are 172mm fans out of switching equipment. I have them wired to 2 12 volt battery backup supplies intended for voip equipment. They will run for hours with no power. Like 6-8 hours for what I have them set at. No worry at all for a normal outage. Most don’t last more then a few hours. Usually less.

Unless your running 12 volt system I can’t see it’s worth
Then agian you may loose electric everytime the rain spits.
If a hurricane knocks out your grow your grow is gone anyway.
As said above maybe to keep pumps running for a bit.
I once went outa town for a few days and spaced my bill
Came home to a dark abode.
I had no electric for 3 days
Paid bill
Lights came on
And plants were no worst for the wear
But I was growing in soil