Yes, i took an old broken dead one and wired about 6 batteries in parallel.. worked great :)

UPS has been around for a longtime to keep critical servers operational. They are very safe.

Only thing is to make sure you have a UPS rated at double the wattage you need. So when you hook up the car batteries the components can handle the extra heat.

Not sure of price comparison but coralbox has come out with a battery back up for jebao.

Coralbox Powercell:
Sample Tests (Jebao RW Pump) Using lowest model W1 Function
RW4 / WP10 48 Hours
RW8 / WP25 24 Hours
RW15 / WP40 18 Hours
RW20 / WP60 9 Hours

For use with Ecotech, Jebao MP, RW, & DC pumps

What CM125 said. When converting UPS to use larger external batteries, you need to be aware of the charging characteristics & capacity of the UPS circuitry. The switching circuit/relay & fusing of the whole shebang also needs to be looked at & modified. If you're not familiar with how that functions, you could be setting yourself up for a disaster. Personally I'm not a fan of trying to do this with something that's designed for a smaller capacity battery. My Dad had a small UPS for his computer years ago. When it stopped working I disassembled it & found the battery bulging at the sides. Could have blown & caused a fire or corrosive damage. I don't think UPS units available for home computer back up are particularly well built. Be careful.

Out of curiosity, what brand/size of UPS are you running?

its a APC 1500 VA one,

I bought a new one for my computer as an excuse to use to use the old one on the tank :)

Like this one>
http://images.highspeedbackbone.net/...-main01-jc.jpg

FYI I believe pets and ponds has the "official" battery back-ups for the jaebo's

I have noticed many people commenting on the 'just essential' equipment during a power outage. I think most would put their return pumps into that category but I disagree.

I do believe it is important and it is something I have planned for but it isn't the most essential, at least not in my set up. I do not have a high rate of water running through my sump, primarily because your water volume through the sump should be only as much as your skimmer can handle (assuming you are indeed, running a skimmer). I know all the rules of thumb X turnover rate per/hour based on the volume of your display tank but skimmers should set that requirement assuming you have an appropriate size skimmer for your needs. So for me, a skimmer is not essential during a power outage and would be difficult to support due to their generally high power load requirements.

Power heads...that's the most important in the power outage, gas exchange is fundamentally the top priority. Tanks can live without dosing, skimming or a 'fuge' for a long time but only hours without good flow.

If you return pump is very large and you are pushing lots of water through your sump then, okay; I can see that being your gas exchange but for tanks similar to mine I would argue that point. 90% of my bio filtration (nitrogen cycle) load is in the tank where 90% of my porous rock is situated. I do have some in my sump but not enough to sustain my tank, so outside of the skimmer and some chemical reactors the sump is secondary to my needs.

I can run for 2 days with no power on my battery backups to the point where, in the winter falling tank temperatures might be the second greatest issue. That is another discussion since heaters draw so much power it wouldn't be feasible on battery backup, it would be generator time for something with that kind of load.

Sorry, just my 2 cents on essentials. I know everyone's tank is different but generally I would say most tanks I have seen the sump is never the primary concern in a power outage.

Yup, totally agree. With our big outage here in the lower mainland just over a month ago, I got caught without my battery/inverter backups available, and lost 4 fish due to O2 deprivation. Have made it through several power outages (and longer ones) in the past, and just kept a couple powerheads going in each tank, and never a problem. They take very little power. Even had enough battery power to turn on the heater periodically to keep the water from cooling too much. Did not need a generator (although had one of those available too, for the freezer).