back up power systems

cuda6872

New member
due to the come & go weather here in cincinnati, we get power outages that last from a few minutes to a week. so far this year nothing bad yet, but before it does happen i was wondering if anybody here has any low buck ideas on a back up power supply that will run the heaters & pumps in my 75? that would include 2 x emporor 400's, 2 x 300watt heaters & 2 x maxi-jet 1200 powerheads. i wouldn't think it would be more than 1000 watts. any ideas would be very helpfull. thanks!
 
I'm interested in this as well. We had a small ice storm around Chrismas and I had to set up an inverter hooked up to my truck out in the garage. It was a pain to hook it up in the middle of the night and run an extension cord all the way across the house. It would be neat if I could get it to cut itself on and off when the power goes off.
 
That isn't exactly what I had in mind. I had one of those (another brand) catch on fire and almost burn my house down. I am looking for something I can hook up to a car battery and run a pump or two for a lot longer than those can.
 
Don't waste your money on a UPS, for long-term backup 6+ hours even more there extremely expensive. You can build one for half that, this is what I use.

-Relay 120VAC coil and 3pdt (3 Sets of NO/NC contacts)
-150W Inverter (You need to get an inverter that has a watt rating of your requirements to drive your equipment; this rating is at a 120VAC level.)
-12VDC charging circuit, preferably from a Fire Alarm, or Security System, I like these because they continually monitor the battery voltage and charge them at a slow rate when its needed, altronix is a good brand to get)
-Case to put the inverter, relay, and charging circuit into.
-2, 12V 55AH batteries is what I use, I also used sealed lead acid (otherwise known as gel cell, there more expensive but do not release toxic and explosive gases like other car batteries and marine batteries do)

If you parallel these batteries together you'll have 110AH. Which is 11AH at 120VAC, you have to increase anything ten fold when you go from 12VDC to 120VAC.

So if you have 150 watts of current draw at an 120VAC level, this would be 1.25 Amps at 120VAC (Watts / Volts = Amps)

Now take this and times it by ten to get your 12VDC amp draw per hour. Which are 12.5.

Now 110AH divided by 12.5AH and we get 8.8 Hours, now no inverter or electrical circuit works at 100% efficiency so now times this by roughly 85% will throw in a security factory too, and we get 7.48 Hours of back for 150 Watts.

For my small 30G aquarium this is more than enough and a outage rarely lasts longer than that, at that point I would just plug the inverter into the car, and back it up this way.
 
A few notes...


the inverter must be a true sine wave inverter. Modified sine wave will not work and can damage your pumps and inverter.

Gel cells are not the battery of choice. You want SVLA batteries without gell in them. Thew newer batteries have a glass "sponge" in them. Gel cells just don't perform well. Deep cycle marine batteries are also fine. You won't blow up the house with hydrogen.

Your relay MUST isolate the inverter power from your fuse box power.... both HOT and NEUTRAL legs.
 
Re: back up power systems

cuda6872 said:
due to the come & go weather here in cincinnati, we get power outages that last from a few minutes to a week.

If you want to be covered for outages last more than several hours (let alone a week), energy storage systems are not the solution. You should be looking at small generators. If you use gas/propane at home, look for a generator that can run on that and you'll always have a large supply of fuel on hand.
 
Yeah, I have been kinda leaning to a generator myself. It would be handy for other things as well.
 
Spend the extra money on sealed gel batteries, or the newer variants that can be charged and stored indoors without the possibility of any gas or liquid leaving the battery. Please, don't cheap out and use marine or car batteries if you don't know how to adequately vent them.

jb
 
Ditto what Jeff said. I've got my return pump on an APC1000 unit, for those short outtages. I get about 30-40 minutes off it (Iwaki55). For longer outtages, we have a gas powered generator. Worth every penny (even if it does PO my neighbors :D ). You can easily wire up one of those portable gas-powered generators to backfeed into your whole house, so in event of longer outtages, you'll be very comfortable (and make serious points w/ your neighbors when you offer them a hot shower on day 2).

- Mac
 
Gell cells are still made and sold, but are old technology. They charge slow and don't discharge well. The "gel" is gelled acid. It can be easily "damaged" (forced away from the plate or boiled) The electrolyte can "stratify" under extreme charge/discharge cycles OR from non use. Gel cells were good when there was no other alternative.... now they are old news and should be avoided.

The newer technology is a wet cell but the acid is contained in a glass sponge. They are called AGM batteries (Absorbed Glass Mat) These are better than both wet cells and gell cells. They don't spill, but they charge like a wet cell. They don't suffer the ill effects that gel cells do. These are called SVLA Sealed Valved Lead Acid.

GRIM is correct that proper ventalation should be used if you intend on using an array of marine batteries. ( I would not worry about using a single battery) I have 2 sump pump backups that are powered by marine batteries... Both are in the house in a semi-confined space. I have measured both spaces using a PID and hydrogen (and other organic vapor) levels are almost non existant.

PLEASE NOTE that these marine batteries are trickle charged. If the cells become discharged THEN YOU SHOULD charge them in a well ventilated space with a proper charger.

Marine Batteries provide the best run times but you have to deal with the spilling and outgasing (not a problem during trickle charging). The AGM types simply provide almost the same performace as a wet cell, but without the safety issues.

I can provide links to plenty of information or you can look on google.

Bean
 
Where do you get SLVA batteries.. walmart, autozone? Or are they more special than that?

You recommend SLVA, but are currently using marine batteries yourself? If I have them outside (in the garage), would deep cycle marine batteries be the best choice.. or SLVA?
 
If you're anywhere's near a large city, check the Yellow Pages for an "Interstate Battery" outlet. I was able to source a lot of exotic sealed lead-acid battery's through them very affordably.

- Mac
 
just a reminder not that it is fish realated, but when you backfeed your house with a generator make sure the main braker is off, if it is on you will not only power your house but also the transformer on the pole in front of your house and when the lineman comes to fix the problem blamo 4160v or so.
 
I mentioned this in another thread...

sailnreef I would take a step further. You shouldnt have a generator or backup supply connected unless you have it on a transfer switch installed by somebody who knows what they are doing.

This includes your backup supply for your fish tank. It should be on a relay that disconnects both the neutral and hot wire from the mains supply.
 
I am usng marine batteries to backup my sump pump. They are cheap and last a long time. Most Sealed Lead Acids have a usefull life of 18-24 months. It can get kind of expensive to replace them every 2 years. The "gel cells" didnt even last that long. A wet cell lasts a LOT longer if properly maintained.

Bean
 
Good point Sailinreef! My electrician friend said you'll prolly burn up your generator as well, as the whole neighborhood tries to feed off it! There's a few of us in the club up in this part of New York (have you found the URS yet Sailinreef?) that lost entire tanks during one outtage a few years ago. Doesn't take too many friends like that to teach me a lesson.

- Mac
 
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