Battery Backup for Main Return Pumps

Discussion in 'DIY' started by magnetar68, Dec 23, 2012.

  1. magnetar68

    magnetar68 Guest

    I have two return pumps in my system. They draw a total of ~150W@2.5A:

    Danner Mag Drive 7 Rated 115V/65W/1.5A -- Kill-a-Watt: 43W@1.05A
    ATB FlowStar 1800 Rated 115V/80W/?A -- Kill-A-Watt: 75W@1.3A

    I would like to put both of these onto a battery backup that will last for several hours. I have a generator for longer term backup, and I have been lucky in that I have been home within an hour of my longer power failures. I would like something that gives me more time of no one home with the water circulating.

    My current plan for the tank is cuttles and I have three tanks plumped together, so I am reluctant to rely on Vortechs with their backup battery since these are expensive and I would need one for each tank. My current tank plan does not need a powerheads other than the main return since it is a soft coral tank with a rather hefty main return pump.

    Here is what I am thinking:
    	[AC]------------------------> [Transfer Switch]---------[Digital Aquatics PC4]--> to Pumps
    Some questions and ideas:

    1) Battery

    Since this will be inside, I am thinking I want a non-vented totally sealed Advanced AGM battery. These seem to be the safest and most efficient batteries on the market. I assume that an RV battery like this one GPL-24T with an 80Amp Hour rating would work for more than a day (80AH for 2.5A = 32 hours). Is this overkill?

    2) Inverter

    I have never bought a power inverted, so the main thing I am unclear on is whether I need a pure sine wave inverter to run a digital aquatics PC4 (i.e., is this sensitive electrical equipment?). Also, since I only need 150W, I assume a 300W inverter is OK. This seems like it would fit the bill: 300W Pure Sine Wave Inverter.

    3) Transfer Switch

    Can I find an inverter with a built in "transfer switch" or do I need to add this after the inverted? I have seen reference to them with built-in transfer switches, but these seem to be hire end models. Also, these seems expensive. I assume they provide uninterrupted switch over, but I don't think I need

    4) DA PC4

    I assume if all of these pumps are set to default on, that this plan will work ok when the power goes out.
  2. magnetar68

    magnetar68 Guest

    One more item is the trickle charger for the battery. Not sure if I need anything special for the larger RV battery. I have a 12V 1.25A Battery Tender from Deltran.
  3. bondolo

    bondolo Supporting Member

    Will your skimmers still be running? I keep hearing that low oxygen and temperature control are the biggest problem for power outages less than 24 hours. There was a discussion of this on Reef Threads podcast recently and what they referenced seemed credible.

    Considerably less advanced than what you're putting together, I've bought a $8 bait pump at Walmart that runs for 16 hours or so on a D battery. I am going to replace the switch with a relay which trips when AC power is shut off. I don't really have a plan for maintaining the water temperature.
  4. aqua-nut

    aqua-nut Supporting Member

    Good topic. The power went out twice so far this morning!

    Just slightly more advanced than Mike's, I have an inverter to attach to my truck when the magic juice stops flowing. I don't remember how many watts it is but it is enough to handle one tank's circulation and heat. I've only used it a few times. I rotated it's use between tanks.

    Depending on your living situation, this might not work. I can park my truck outside, running, and have a reasonable expectation of it not being stolen. Helps it's a 10 Y/O truck! :) Also the distance between truck and tanks is not that far. Heavy duty extension cords do the trick.

    Heat wise, it matters a lot what kind of tank you have and the temp of the room the tank is in. Large acrylic tanks don't loose heat as fast as glass. I forgot to plug in the heater on a 60G and after 5 days it was still above 70 degrees. Overall I would rank circulation much more important that temp. No oxygen/dying bacteria gets deadly quick.

    In the 20 yrs. we've lived in this house the power has been out once for 4 days and several times for 4 hours. The 4 day time I didn't have fish, just cold children. I used the inverter the other times.

    If you have a controller, a UPS that can keep the controller and your internet connection up would be great. That way it could warn you with texts or email. At that point you would need to either personally attend to it or have other back-up personnel available.
  5. Sorry, I seem to be having trouble with reading comprehension today - you don't already have Vortechs, do you? If you do it's incredibly easy to make a DIY battery backup for them (along the same lines as what you've already spec'ed for your other pumps, but with a smaller 12V SLA battery and trickle charger, and you could link all the Vortechs to one battery backup). Since Vortechs already operate at 12V the efficacy on battery power is greater than converting 12V to 120V to run the return pumps.

    This is a good time to be checking the battery backups, thanks for the reminder sir! :)

    BAYMAC Guest

    Did they reference Eric B's study where he determined skimmers don't add much DO to the water? You're really just driving off CO2 and adding a little DO, but not much. Driving DO up via water movement is very inefficient IME.

    Around here, water movement is the largest factor since it doesn't snow. Having temps drop into the 60's is not that bad, and it increases DO. Most your animals from the wild have been shipped in mid 60's water.

    Careful with those bait pumps... they are known to use metal screws with questionable types of metal, and sometimes are oil filled.

    BAYMAC Guest

    Tunze also makes a 12vdc part to allow for an assembly like this to be used, but the pumps will still run at fill power unlike the Vortechs.
  8. magnetar68

    magnetar68 Guest

    I was not going to run the Skimmer too, but that would only add about 40W to the load, so I think this type of setup could still run the two returns and the skimmer for a day.

    In terms of heat, I am a little concerned, but the 125G is 3/4" acrylic and the sump is 3/8" acrylic, so a large part of the water volume is well insulated. The 20G and 29G are glass, however. I still think I could get by with a slow gradual drop in temp from 78F to 68F over day and not loose most of the animals. At least I have had both types of heat issues before: drop to high 60s and rise to low 90s and I did not immediate lose anything. The tank will be mainly soft corals and the cuttles.

    I do not currently own any Vortechs. I have two Tunze 6105s, but I don't like covering them in foam as this gets clogged quickly, so I do not think battery powered power-heads are a good option for a cuttle tank.

    I am most curious about recommendations on the inverter and the transfer switch. Anyone have any personal experience here?
  9. magnetar68

    magnetar68 Guest

    I spoke to a guy at The After hearing what I was trying to do, he recomended the following unit. It's pricey ($599), but not super pricey compared to buying 3 vortechs and the battery backup units.

    He said to get a unit that is rated for 3x the expected load. This is the smallest "Inverter Charger" they carry, but it is a little beefier than I need. This one has everything I need in one shoe box size unit: inverter, smart charger for any type of battery, and a transfer switch. I would just need to plug this in, attached the battery, and plug the DA PC4 into here. It automatically handles the rest.
  10. BAYMAC

    BAYMAC Guest

    3x? I always thought the rule was 2x, good to know!

    Sounds like a winner to me :)
  11. rygh

    rygh Supporting Member

    I went and read Eric Borneman's study, and got the opposite impression.
    Different study? Am I missing something?
    Look at table 5, about half way down.
    The skimmer took a hypoxic tank to O2 saturation in 20 minutes, where the air stone took 60.
    Look at table 4, and an air stone is way better than Cheato.

    So to me, that means that a skimmer is REALLY good at pumping up O2 levels.

    Which makes a lot of sense from a physics standpoint - high surface area, high turbulence, lots
    of flow = good diffusion of CO2 out and O2 in.
  12. BAYMAC

    BAYMAC Guest

    No, I was assuming his IMAC presentation and the article were the same, and they are not. I saw the presentation.

    FWIW odd way of showing DO levels. Guess it wouldn't look as impressive had he used % of DO instead of saturation... you'd then only see a few % change.
  13. zeroinverse

    zeroinverse Guest

    Baymac and rygh, do what was decision on oxygenation?

    As for battery backup, it seems to me if you have 12VDC type pumps, you should not up convert a 12v battery just to power 110 pumps. Coralvue has the 5600 or 2600 pumps that run off DC. Not as fancy as Vortech pumps but may be a good choice for battery backed up tank circulation.
    (I just dislike their "suction cup" attachment mechanism.

    I have the Coralvue 5600 pair with an MP40w running in my tank. I will "eventually" setup battery backup.
  14. Very glad to see you in the BAR forum!

    You've probably got a bunch of other things on your plate with setting up the man cave, but it takes only 30 minutes (probably less for you) to put together a DIY SLA backup for the MP40. What's holding you back?

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