DIY power backup

[Davidb6]

With hurricane season approaching, anybody have a simple DIY power backup systems they can recommend?

I’m thinking of something very simple just to run a couple power heads for maybe a day or two. Maybe a simple trickle charge battery charger hocked up to some type of converter…power goes out…battery kicks in. Would like to keep this setup in the basement with power running up to the tank on the 1st floor.

I’m sure somebody did this already.

Thanks

[lecher]

A couple of deep cycle batteries and power inverter would work or better yet buy a small generator.

[Aqua Keepers]

I've read that you can use a couple of deep cycle batteries and power inverter hooked up to a relay so that it switches on automaticly, but have no Idea how to do that. Does anyone know how or have a link?

[BeanAnimal]

A couple of 'days' is going to be a challenge if you do not put some thougt into what you are doing.

Lets say you have (3) 25 watt power heads.

Now lets say you have 50Ah worth of batteries.

75W / 120V = .625A

Now lets say that you have an 80% efficient inverter with a "perfect" battery. So you have 40Ah worth of energy to use.

So in theory you have 40 AMPS for 1 Hour or 1AMP for 40 Hours. You are drawing .625A so you have 64 hours of runtime (in theory). However batteries are not perfect and discharge following a curve... So you really end up with maybe 35 hours of run time.

It is more complicated than that in reality...

http://www.powerstream.com/battery-capacity-calculations.htm
www.majorpower.com/inverters/battery_sizing_faq.pdf

You want to use a TRUE Sine Wave Inverter.

Instead of us explaining how to DIY a UPS system... look for a long thread by a guy named playfair. He did a decent job on one and listed the parts he purchased.

[Aqua Keepers]

http://reefcentral.com/forums/showthread.php?s=&threadid=64918&highlight=battery

Found it. All the pics are gone, but I'll read it later.

[Young Frankenstein]

The only problem with inverters is they produce a square wave instead of a curved one, that may stress some motors, power heads etc. for backup I use a DC submersible bilge pump. Here's a thread below.

[Young Frankenstein]

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1177360

[Young Frankenstein]

and here is an ATS I made for you :D
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1178316

[Aqua Keepers]

AWE, just for me!!!???

Thanks

[BeanAnimal]

<a href=showthread.php?s=&postid=10486860#post10486860 target=_blank>Originally posted</a> by 0 Agios
The only problem with inverters is they produce a square wave instead of a curved one, that may stress some motors, power heads etc. for backup I use a DC submersible bilge pump. Here's a thread below.

By Beananimal
You want to use a TRUE Sine Wave Inverter.

:)

[Young Frankenstein]

<a href=showthread.php?s=&postid=10487221#post10487221 target=_blank>Originally posted</a> by BeanAnimal
:) I concur :D

[BeanAnimal]

Yeah motors don't like step waves or square waves at all :)

[luke33]

The last hurricane I went through i was without power for 8 days......total devistation and had to start over as i couldn't even get to my fish for 4 days. So I would plan on more than 2 days......i don't have to worry about that anymore now that i'm in fabulous Indiana(lol)

[rbc1225]

Look at my thread here.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1178360

Do the mod on a DC pump and use the small 360gph pump. Once the mod is made it is pretty close to the MJ 1200 Mod. I can't remember off hand but I think the 360gph pump uses approximatly 1 1/2 amp. Purchase a deep cycle battery to run it . It would only depend on the size of battery you purchased. Of course they get more expensive the more amp hours you need.

I know it is not the cheapest solution. But it would work.

Rusty

[BeanAnimal]

The only realistic way to supply power for more than a few hours (or a day) is to use a generator.

The cost in setting up and maintaining a large battery array is fairly substantial.

You can get a small 4000W generator for around $350 shipped. Look for the buffalo tools brand. The engine is a HONDA knock off.

For a little under $3000 you can get a standby genset that runs off of propane or natural gas and starts on its own. If you are in a hurricane area, this is a very wise investment.

[Davidb6]

Good point about return on investment....at what pint does it make sense to go with a small gen.

Any feedback on very small generators? In my case I'm only looking for a couple Hydro power heads and maybe one heater (assuming it could be winter)

Thanks

Also, for my (small tank) situation maybe and battery system is better??

[BeanAnimal]

You can get a very small genset for a few hundred bucks.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94678 $200

At 1000W it would likely run the whole tank. You could use it to keep your battery backup charged also.

Spend a little more and you get a LOT more power.

They cost money to run, but they are worth the money if it saves your livestock. On the other hand a battery backup system costs money no matter if you run it or not. Batteries have a finite lifespan and start degrading in performance the day they are made. After about 18 months, the batteries begin a much more rapid degredation.

If you need 48 hours of runtime with a battery array, you need to purchase an array that is about 70 hours. That way a year or so into the arrays life, it will still give you 48 hours, not 30.

Your car battery should be replaced every 18 months. How many of you do that? Just because it has enough current to start a car after 3 years does not mean that the battery is in good shape.

[miwoodar]

More links to a DIY backup are here on page two:

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1173100&perpage=&pagenumber=2