cheap, reliable UPS for reef systems

[keitho]

hi everyone...
i was recently looking into a cheap, affordable emergency UPS for my aquarium. shocked at the outrageous prices gel cell UPS manufacturers wanted, i decided to see if i could come up with something better and cheaper (and possibly put those five years of engineering school to the test). well, folks, this is what i came up with. a bare bones system can be created for about $100. all you need is a 12V DC to 110V AC power inverter rated at 350W or better (i got mine at Sam's Club for about $30), a deep cycle marine battery with at least 75 Amp Hours of capacity(available at hardware stores or WalMart for about $40), and a 10A automatic battery charger (again, WalMart for about $30). you plug the charger into the wall, charge up the battery, and connect the inverter to the battery. the inverter has a couple of regular wall-type outlets for powerheads, air pumps, etc. on a fully charged battery, if the power kicks off, the battery automatically powers the inverter which can power your critical powerheads/air pumps for up to fifteen hours (depending on powerhead/air pump power consumption load). in short, you can get at a minimum about 10 hours of emergency power with this easy to install, reliable system. anyway, just thought you guys might like to know. please feel free to ask questions.

 

[dad]

huumm, really confused with this one. First of all, a automatic charger will keep a battery up. second; an inverter will work,i'll agree. The problem is that there is no transfer switch to switch the 120v devices from your house to the battery back up.
You cannot have them plugged into the house and the inverter at the same time.
This may be called a emergency backup and will only work if you are there to replug things but not a ups.
Do not want to burst your bubble but I do not want people going out and spending money on something that doesn't work like they were told.sorry,

 

[chocochipper]

Just out of curiosity, is this battery that you got 100% sealed as to prevent fumes and or acid from leaking out?

 

[keitho]

okay...lets go over this again. it DOES work. i use it right now! the charger is plugged into the wall. the charger is attached to one set of posts on the battery (i bought a battery with two sets). the inverter is attached to the other set of posts. critical equipment run off of the inverter ALL THE TIME. the charger maintains the battery and powers the inverter when household power is on. when household power is OFF, the battery continues to power in inverter, uninterrupted, until the power comes back on. trust me, it really does work. i had a test load of 80W on the inverter/battery combo for over six hours with and without household power. it could have gone a lot longer, but i got tired of watching it! also, you don't need a transfer switch unless you want to try wire up a relay that opens when household power goes off (which is NOT necessary if you configure it the way i stated). the problem with the transfer switch is that it usually requires a manual reset to start using household power again (unless you have an automatic one). also, resetting the switch would require you to be there to reset it! if you don't believe me, that's fine....but it DOES work as i am using it now. and, yes, you should try to get a sealed battery. they make good, durable gel cell deep cycle marine batteries for just a tad more. FYI

 

[johnnysalt]

thanks Keitho!
That is exactly what I was looking for, as those UPS's for comp's, etc are are pretty expensive for only a few minutes of power!
Hey btw, I'm in D/FW too....do you know about the reef keepers club here?! email me if you want...it's in profile. Thanks again for that DIY project...that was a good one!

 

[broomer5]

keitho
I love DIY projects and this sounds great. I've been looking at various options for power loss, since I travel quite a bit.
This sounds great ! Wondering if I could mount all the equipment in a vented enclosure, or if it produces too much heat ???
I now know what I will spending some of my "Tax Relief" money on soon

 

[dad]

hey Keitho.
sorry, I didn't understand that it ran off the inverter all the time. with that in mind; i see how it works! thanks and sorry for the mix up.

 

[keitho]

hey guys...
i'm just trying to help you guys out. i'm NOT trying to lead you astray and i'm NOT trying to get you to waste your money. my father (who's an electrical engineer) and i devised this method to be a crude, lifesaving emergency backup power system in the event that the power goes out and we are not around. i hope you guys understand the concept and realize that it is a worthwhile investment. hope this helps....