Battery Bank

dhill
dhill Solar Expert Posts: 47 ✭
in Advanced Solar Electric Technical Forum #1
I've upgraded my solar panels, and I'm preparing to upgrade my battery bank. Thanks to many of you here, I've learned what type of battery bank I'd like to use. But Wind and Sun sells this battery http://store.solar-electric.com/crdecyinba1.html and I'm wondering if it would be possible to use such a mammoth item in my set-up. Is 1100 watts of pv enough to charge the 935 ah battery? Are these impossible to move around or is there a way to put it where you want, perhaps using a piano dolly to get the thing set in place? The reason I'm looking at this is because it simplifies my system, one 24v battery instead of 8 6v batteries for the ahs I'm needing. Cost would be similar to buying 8 agm batteries. Those would give me about 800 ah of stored energy. Anybody have any thoughts on this? Thanks for the input.
Dusty
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Comments

  • System2
    System2 Posts: 6,290 admin
    #2
    Re: Battery Bank

    Dusty
    I really like their reccomendation: forklift or crane! If going in a garage maybe they could be let down off truck on some 2x4's that you've greased. Push with big garden tractor or brother-in-law's 4x4 pickup (everybody has a bro in law with one?). THis is somewhat like the pyramids were built. Grease and lumber.

    If needed in a basement...har har. Good luck

    ralph

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  • rplarry
    rplarry Solar Expert Posts: 203 ✭✭
    #3
    Re: Battery Bank

    Dusty
    I have never seen this particular battery but many times the manufacturers put 12-2v cells inside the metal case. So maybe you can remove the individual cells and move them one at a time to where you want them and then put them back into the yellow metal case. My battery bank is like that, I have six 2v batteries that weigh 267# each. No way can I move them altogether, but individually I can do it. Ask NAWS if the batteries can be removed from the yellow case.
    Good Luck,
    Larry
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  • dhill
    dhill Solar Expert Posts: 47 ✭
    #4
    Re: Battery Bank

    Thanks, guys. Moving this thing could be a problem, but not impossible. I'm in the middle of ranch/farm land. Lots of tractors around. I could possibly rent a forklift if needed. I have to get the battery inside a shed though. That's why I'm wondering if a piano dolly might work. I've moved more than one heavy piano, but I'm not sure those weigh 3/4 ton. Lots of thoughts about this, so any advice is appreciated.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #5
    Re: Battery Bank

    well i'll give my 2 cents worth.

    I'm wondering if it would be possible to use such a mammoth item in my set-up.
    yes, you could.

    Is 1100 watts of pv enough to charge the 935 ah battery?
    marginally, but yes. i figure the charge rate to be around 3.4% with 1100w of pv based on W=VxA and V being 35v.

    Are these impossible to move around or is there a way to put it where you want, perhaps using a piano dolly to get the thing set in place?
    impossible no, improbable yes. this is more weight than individuals would normally attempt to move let alone place into your home. this isn't something you could just put onto your floor either without special considerations being met as this would far exceed the load bearing capacity for most residential homes unless it's going onto a concrete floor. it is an industrial battery and they will put this into a fork lift that runs on good solid flooring such as concrete. ironicly you need a fork lift to mount it.

    you may be gaining some ah capacity, but agms are more efficient than lead acids so i'd say they're breaking close to even. the largest common agm size is 255ah at 12v and although you need more batteries it's not as tough of a task to move more smaller batteries. even with more smaller batteries, care and attention should be paid to how they are supported.
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  • dhill
    dhill Solar Expert Posts: 47 ✭
    #6
    Re: Battery Bank

    Thanks, Niel. Sound advice. The floor is concrete, but I have no idea what the load limit would be on it, hadn't really thought about that, and I'm betting that at best the floor would crack, and at worst, the load would sink. Oops, that might not be a good thing. Maybe I'd be better off with the AGMs. I sure like the idea of having only one battery tho plus the advantage of it being 20 yr life span.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #7
    Re: Battery Bank

    i think you'd be safe for loads on the concrete as long as it's not suspended, ie: it's laid onto the ground and the concrete is not supported via other means.
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  • arcandspark
    arcandspark Solar Expert Posts: 63 ✭✭✭✭
    #8
    Re: Battery Bank

    Dusty, I had GNB Asbestolyte III AGM batteries and one big problem I found here in Texas is during the winter time if they fall below 36 to 32 degrees they crack, the gell inside expands. The owner of the batteries did not turn on the battery shed heater during the winter and most all of them cracked at the bolt terminal. True they work for many years in Telecom central offices but those phone company buildings are heated during the winter. I am now using Hawker VRLA gell cells and they have been working very well. I use a couple strings of Xmas lights mounted under the battery stands and during the winter the Xmas lights generate enough heat (each string about 120 watts) and with the batteries covered they stay above 42 degrees when the outside air temp is in the 20's. I plan on using all wet cell batteries in the furture. They are very robust and can take far mmore abuse then any other type battery out their. I think you and I have meet once you purchased some items from me, I live in Plano Texas. Glad to see your system is doing well. Dave R. (arcandspark)
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  • dhill
    dhill Solar Expert Posts: 47 ✭
    #9
    Re: Battery Bank

    Dave,
    Thanks for the info about the gel cells. I hadn't thought so much about the problem of the cases cracking. Is that trun of all sealed batteries? I've read about your Christmas light idea. What type bulbs do you use? My shed where the batteries are kept is unheated and not likely to be heated. I use an electrical heat tape on my water pipes that are running there. I'd like to cut that watt use to about half. Do you think enclosing the AGMS in a box and putting a 60 watt bulb inside the box would keep them warm enough?
    We have met. You kindly gave me some batteries that I used in my initial set up. Those batteries worked well for me and were exactly what I needed at the time. My system has worked well for the last year, and I'm a testimonial that it doesn't take much to run a home off grid. I have no expertise or electrical engineering savvy like you and many others here, but I've managed to use a little common sense and set my system up following the directions provided me by the various manufactures and solar experts, and basically I just run what I run. My only inconvenience is that when I run my 1000 watt microwave I start my generator for a few minutes so that I don't pull down my battery bank unnecessarily. If I had a remote start device for my generator, that wouldn't be inconvenient either. Push a button for on / push a button for off. It's the way of accustomed living. As it is, I have to walk 30 feet outside to turn on the gen manually.
    Have you seen the notice about the buy-out of TXU. The new owners are attempting to be RE and environmentally friendly. My son's company has developed an air conditioning system that is ultra-energy effecient. TXU has committed to supporting the production of these units as an alternative to building their coal plants. We'll see how that goes. So far they've only given verbal support and have not issued any funds.
    Thanks for the help with the batteries, all.

    Dusty
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #10
    Re: Battery Bank

    dhill,
    i think i speak for the majority of us that we'd like to hear of the developements he's made with them in re and particularly in air conditioning. if you wish to elaborate to us on this please put it in energy use and conservation(prefered) or in solar basics, but not both. thanks.
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  • dhill
    dhill Solar Expert Posts: 47 ✭
    #11
    Re: Battery Bank

    Niel,
    Thanks for the interest. I'll post some specifics soon about the advancements in air conditioning. They've been working off of government grants and up front monies from industrial groups. A million here and there. Austin's energy supplier is working first hand with them. You guys will understand all the data from the web-site. I'll post the link soon.
    I've talked to the inventor who runs the company. The best thing about his stuff is that it all works, and it all works according to how he says it will work. I've offered my house as a testing ground for him, but he's been too busy in the shop and in the field with paying clients to mess with my stuff yet. But I'll get the benefit of it soon enough :-).
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  • arcandspark
    arcandspark Solar Expert Posts: 63 ✭✭✭✭
    #12
    Re: Battery Bank

    Dusty, As for the case cracking on all sealed gell cell batteries I cant say but GNB warns not to let them get below 32 degrees and the owner did just that and they cracked. I use regular Christmas light strings for keeping the batteries warm. The batteries are on pallets per Hawkers recommendations and then I put aluminum foil on the floor under the pallets to reflect the heat and placed two strings of lights (rated at about 120 watts each) under the batteries on the alumimun foil. The heat from the lights flows up through the battery cases by convection, covering the batteries with mylar helps trap and keep the warmth where it is needed. The lights are hooked to a temperature control switch that turns them on when the temp in the battery shed fall to 38 to 40 degrees F. On days with outside temperature in the 20's the lights usually come on in the early morning hours and turn off some time before noon. Another idea I use is any time the generator is used for charging purposes in the winter, it turns on an oil filled heater in the battery shed when the generator turns on. I used oil filled because there is no fire related problems, no open heating elements, no sparks. This oil filled heater heats up powered directly from the generator when its running and when the generator shuts off the heat from the oil in the heater keeps warming the shed for a couple hours after the generator has been turned off. It works great. I use a 5000 BTU window air conditioner to keep the battery inverter shed cool in the summer, usually set to turn on then the inside temp get above 85 to 88 degrees F. Its been working great for a few years now. Dave R> (arcandspark)
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  • crewzer
    crewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    #13
    Re: Battery Bank
    I had GNB Asbestolyte III AGM batteries and one big problem I found here in Texas is during the winter time if they fall below 36 to 32 degrees they crack, the gell inside expands.

    As for the case cracking on all sealed gell cell batteries I cant say but GNB warns not to let them get below 32 degrees and the owner did just that and they cracked.

    Dave,

    I have no reason to doubt anyone’s word, but the examples cited just don’t make any sense unless the batteries were severely discharged.

    For example, Exide’s GNB Absolyte IIP AGM batteries (not Asbestolyte, not III, and not gel) are used in a variety of applications, including railroad signaling, which I presume is subject to all manner of environmental conditions. Exide’s approved operating temperature range (for fully charged batteries, I believe) is “Temperature excursions between -40°C(-40°F) to +50°C(122°F) allowed…”. The spec also says that battery performance and life will be affected, but that’s true of all flooded-cell lead acid batteries, not just VRLA (AGM and gel) models. See: http://industrialenergy.exide.com/exidepdfs/Absolyte_62_61.pdf

    From another perspective, here’s a link to Dynasty’s VRLA battery notes for cold temperature performance. Note that their freeze spec for a fully charged battery is -95 F. See: http://www.cdtechno.com/custserv/pdf/7953.pdf

    Similarly, MK Battery, a subsidiary of East Penn, specs the operating range for their AGM batteries to be -40 F to +140 F. See: http://www.mkbattery.com/images/8A8D-LTP.pdf

    So, while I have no doubt that the battery cases may have cracked, I doubt that it was solely due to mildly cold temperatures. Instead, I’d consider other causes such as overcharging, poor temperature compensation, and/or series battery imbalance (low voltage on some cells, high voltage on others).

    HTH,
    Jim / crewzer
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  • arcandspark
    arcandspark Solar Expert Posts: 63 ✭✭✭✭
    #14
    Re: Battery Bank

    Crewzer, The batteries had been disconnected and were sitting for many months unused and may have been in a discharged condition. I had installed the larger Hawker batteries. The owner said he had forgotten to put a heater in the battery shed and the temp in the shed had fallen into the twenties. I had thought I read some GNB spec's once that said not to let the temp get below 32 degrees, I might have been mistaken, it was a few years ago. Personally I like the GNB's, we used them in all the Telecom Cell Site Installations we did when I worked for Nortel. Dave R>
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