Aquion Energy "Cost Effective"?

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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Golf cart batteries - just 2-3 years, learners usually kill them by the first fall/winter when there is low sun
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    mike95490 wrote: »
    Golf cart batteries - just 2-3 years, learners usually kill them by the first fall/winter when there is low sun

    If reasonable well maintained I think 4-5 years is reasonable, I posted my experiences in the fridge thread and I'll copy here my last set of golf cart batteries;

    About golf cart, forklift and solar batteries. Batteries may vary in design, but they don't know what they are hooked up to... We call golf cart batteries that because they are most commonly used as golf cart batteries, same fork lift and floor scrubber (L-16 interestingly L-16's were often called boat batteries where I was in Florida as they were used in commercial fishing boats)

    The reason the 'golf cart' batteries are a good value is that they are mass produced, same for fork lift batteries. The batteries don't know what they are hooked up to! The metallurgy is pretty much the same. Car batteries will normally be Lead Calcium, they have excellent long term storage, but poor cycling characteristics, Deep cycle batteries tend to be Lead Antimony, which has much better cycling characteristics.

    Solar is catching up, I was surprised recently when someone was suggesting that the HUP1 was the best value in solar batteries, I checked there website for the first time in 3-4years and found that I don't think they have increased their prices in the 10 years or so they have been producing them, and they are getting to be a pretty good deal. The HUP1 is pretty much a 12 volt modular forklift battery for solar. I don't know(or think) the plates are much different from standard forklift batteries, but I think the design has more electrolyte above the plates and perhaps more area below the plates as well. Forklift batteries tend to be maintained daily or at least weekly, while it's normal for solar batteries only to be maintained monthly...

    Here's a pretty good paper on batteries, it's amazing that the design varies so much between US and Europe!

    My golf cart batteries, the last set I used to completion, I purchased 4 and had them hooked up in series and parallel in a 12 volt system for the first year, I was moving and knew I would switch to a 24volt system, I was living very minimally fans, lights, computer time, a little tv and mp3 music player, and a vcr some. with fans in the summer time, I was pretty much fine on a 2 golf cart battery 12 volt system.

    After a year, I moved increasing the array to @1000 watts and used the same 4 batteries, now in series for 24 volts, I used them with a window air conditioner only at night, unless I was away the previous night and the batteries topped out(reached float) early. I ran the A/C 4-5 hours a night in my well insulated cabin, that first summer The batteries had a higher duty cycle, likely 60-70% at least the first couple hours. Likely brought the batteries down to 60% SOC nightly for 8-12 weeks and maybe as low as 40-50% some nights, but our heat comes with sun so I cycled them like that and they worked well through out the summer, In the fall I added a small fridge and 350 watts of panels. I was working within a mile of home and had a fridge there. the next summer I shut off the fridge and was able to run the a/c some during the afternoon directly from the array so likely used less energy(lower duty cycle since the cabin was cooled down). Again in the fall I added another 350 watts, about max for the 4 GC's on a PWM charge controller. I ran the fridge through out the summer the next 2 years.

    So 5 years, torturing the batteries during the 4 summers. Please note that the hard cycling isn't as hard on the battery when they don't sit at a low state of charge. I don't know for sure, but suspect one long winter period of no sun for 7-10 days running the battery bank down to 30-40% SOC might be harder than a whole summer of cycling nightly being charged back quickly, though the higher temps of the battery will also shorten the battery life. My batteries have always lived outside.

    On the temperature note, CaribouCoot has been able to get 8-9 years or more, out of standard GC batteries, in the wilds of western Canada. I suspect part of the reason is they is they live 6 months out of the year in very cold temps.

    Many people here would and have suggested golf cart batteries for your first set. I would unless you will need more capacity than a single string and in most cases 2 strings of these batteries.

    On an additional note, I noticed that the Sam's club GC batteries are now rated at 208 amps hours, I think the set I was referring to was rated at 215 ah.




    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • cyigshAb1
    cyigshAb1 Registered Users Posts: 2
    Aquion S20 cost ~$1100 ea. + non-hazmat shipping 260lb
    At about 2A charge/discharge per stack, around 2.3kwh per 100% cycle.
    3,000 cycle life @ 100%. At the end of  cycle life it is reduced to ~80% capacity according to operations manual. I see sellers quoting 70% for some reason.
    $1100 / 3000 = $0.36 per 100% cycle assuming 70-80% wear-capacity is the lower tolerable limit before replacing them.
    $0.36 / 2.3kwh =
         ~$0.16 overhead cost per kwh passing through battery.

    Trojan L16RE-2V  - a pretty good flooded battery. (http://www.trojanbattery.com/product/l16re-2v/)
    ~$325 ea + hazmat shipping 116lb
    Cycle life 1600 @ 50%. Don't know wear-capacity after this.
    2.47kwh@20hr * .5 = 1.24kwh per cycle
    $325 / 1600 = $0.20 per 50% cycle.
    $0.20 / 1.24kwh =
        ~$0.25 overhead cost per kwh passing through battery.

    Doesn't include support equipment and shipping.

    Aquions are generally cheaper in the long run. They have the cheapest residential-battery cost that I can find. Powerwall is close, less if purchased wholesale, but those odd high-voltages can mean an expensive inverter.

    It should be getting obvious that battery storage is expensive in general and is the major barrier to practical off-grid solar. Schedule loads during peak sun whenever practical - it's much cheaper than sending everything through batteries.

    Aquions are simpler than lead acid in terms of charging. Don't need absorption/float; I just charge them up to 57V and leave them there using a Schneider C40, with absorb/float both at 57V. Current is self-limiting on them. No sulphate, etc. Don't use equalization-  it does nothing good and can damage the battery.

    Inverter's fine so long as it handles 44V-57V. SK1500 gives warning lights but doesn't fail.

    They cannot be used when they (not the air around them) are below 24F; they freeze around -5F and can be damaged when that happens.

    The voltages sag more than lead acid. A conservative off-grid residence needs at least 8, assuming you aren't running a compressor, welder, etc. (I recommend load-scheduling the compressor to peak sun anyway instead of wearing out the batteries) I have two for emergency power and I can't pull more than ~600W surge per stack without inverter shutdown.

    Transport's a pain. Very heavy, can't be tipped more than 15 degrees, no handles - has a loop on the top for lifting and needs two people with a metal bar sent through the loop or a small crane to move.

    Their behavior is in akin to NiFe or LiFePo family of batteries: Slow charge/discharge, heavy, cheap and sturdy.
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,731 ✭✭✭✭✭✭
    edited April 2016 #36
    There is still the loss of using low voltage. The powerwall concept (and others much more reliable than Tesla) are working on this, trust me. It will have a dual input or more high voltage charge controller that does not have to step down much in voltage. It will have an inverter that does not need a huge toroid transformer and it's losses, because it has high voltage input.

    I think your example is really not the whole story offgrid because we generally do not cycle to 50% in good systems. We  generally use
    more solar because of winter and so the loss really is not that much of an issue. The systems are generally designed for winter and also the cost of the battery is smaller, if it goes for 10 years.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • cyigshAb1
    cyigshAb1 Registered Users Posts: 2
    A check on my math shows I did the final calc on the Trojan wrong; it should be $0.16 per kwh passthrough not $0.25 - will edit it when I can. To be sure I calculated on a spreadsheet, below are the results. Also factored in are DoDs as given on the Trojan website. Something unexpected was the dip around 60% DoD.

    DoD Cycle Life Kwh/passtrhough $ per cycle cost per Kwh passthrough
    0.2 4000 0.494 0.08125 0.1644736842
    0.3 2750 0.741 0.1181818182 0.1594896332
    0.4 2000 0.988 0.1625 0.1644736842
    0.5 1600 1.235 0.203125 0.1644736842
    0.6 1450 1.482 0.224137931 0.1512401694
    0.7 1200 1.729 0.2708333333 0.156641604
    0.8 1050 1.976 0.3095238095 0.156641604
    0.9 900 2.223 0.3611111111 0.1624431449
    1 750 2.47 0.4333333333 0.1754385965