Battery Bank

Discussion in 'Off Grid' started by Minnesota, Jul 23, 2011.

  1. Minnesota

    Minnesota WindyNation Engineer

    What batteries do you use? Most common are 6V golf cart deep cycle flooded Lead Acid either:
    Trojan T105; 225AH
    Interstate U2200; 220AH
    Exide GC135; 226AH
    Rav-O-Vac Ultra Pro line; 215-255AH

  2. TomT

    TomT WindyNation Engineer

    I was going for Exide 6 v golf cart batteries. But the dealer at the last minute received some used large Exide 2v 530 AH cells. Sold them for scrap price and delivered them for free. I have not put a charge into them for 3 months and voltage is still at 12.25 volts. Same place as it was after 2 days of not putting a charge in. This is supposed to be dead but it is still high enough to run inverter. 12 v fluorescents will run for days at this level.
  3. Minnesota

    Minnesota WindyNation Engineer

    One golf course says they keep batteries until they can't go 2 full rounds each day on a charge. I'm curious if anyone has had success with used ones like these, allowing them to provide years of suitable service as part of a battery bank. Going "used" is a form of being green/recycling/reusing.
  4. Minnesota

    Minnesota WindyNation Engineer

    Stopped into the Interstate retail store and they were very helpful. Their "old" U2200 6V golf cart battery was made by others (US Battery) but now they make their own called the GC2-XHD-UTLIVC. They claim it performs better. The RV crowd also seems to prefer the Interstate over the Trojan. $139 each, or $120 each if you buy 4. 235AH each. Core charge of $10 if you don't have a trade-in. 12m warranty. They also have ready made cables for golf cart banks (usually 6 batteries) for $5 each (6AWG).

    So get 470AH on a 12V setup for ~$500 with cables. In practice you want to use only 1/2 of that (235AH).

  5. I have 4 t105's @ 96.64 each from tri state battery supply of tx. total of 450ah. plan to add 2 more for 675ah.
  6. Minnesota

    Minnesota WindyNation Engineer

    Wow ... great price Larry.
  7. Hey guys I bought 4 of these at Sam's. what do you think about this battery? photo.jpg
  8. Minnesota

    Minnesota WindyNation Engineer

    leamywind1 likes this.
  9. Andy R.

    Andy R. WindyNation Engineer

    You might find this interesting. (Maybe not) but anyway, my 1st alternative energy project back in 1992 was to power a CB radio in our off-grid cabin. I bought a 35 dollar car battery of not more than a 5 year warranty and the system performed flawlessly for 13 years before I needed to replace the battery. I know, that sounds like science fiction but I attribute it to this, I powered it with a 6x8 inch solar cell which trickle charged the battery and I pretty much never ran it down. I'd only used the CB once or twice a month at the most and the battery never was "Deep Cycled".
    So, at that rate of getting 13 years out of the 1st car battery and then replacing it 7 years ago with another car battery, I should be due for a new battery in 2018. At that point I will be 65 years old and tonight I'm thinking about replacing it with a deep cell so that should maybe take me up until I'm about 90.

    Check out the baby solar cell. The 1st one lasted 17 years and cost 32 bucks.

    leamywind1 and TomT like this.
  10. leamywind1

    leamywind1 WindyNation Engineer

    Is there a big difference is using 6v batteries to using 12v batteries? I use 12v to take up less space.
    Plus they are easier to find. I also have the Energizer type batteries i bought from Wall Mart 3 years ago and they are just fine. I beleive they are 115 AH ea. I have 10 of them. I do not use them that much but when the power does go out i have a big smile from most of my interior and exterior lights being powered by them. All LED lighting of course.

    my led bulb.jpg 10 bucks at Home Depot and super bright. We have 40 of them in our home.
    They are dimable and draw 8.6w ea. Color is 3000k (warm white) and 429 lumens. Rated for 50,000 hrs of use. The batteries love these bulbs.
  11. Hi leamy KEN F here. Just wondered if you know Ronnie Freeman. I had him repair one of my Sun inverters and he asked if I talked to Larry. Thought it might be you. If so this is what he wanted to tell you. Hey the next time you talk to larry see if he got his inverter going, i sent him a mosfet to repair his 500w but have not heard if he got it going or not. Just checking to see if it was you. KEN F
  12. Thanks for the tips Larry. I also have started replacing with the led lights and the corkscrew type, just trying to save a few pennys
  13. batterie.jpg
    Hi here is my 1600ah@24volt forklift battery , :)
    timber, leamywind1 and Minnesota like this.
  14. Man I priced those Forklift batteries and holy crap I'd have to go back to work.
  15. :D

    not too expensive for what you get, a new one in this size cost about 3500 Euro (here in Europe ) so about4500 $(i suppose )
  16. leamywind1

    leamywind1 WindyNation Engineer

    Thnak Ken, yes i know Ronnie. I get my inverters from him and have sent others to get repairs. I did get my inverter to work. Thanks for the heads up i will let him know asap.
  17. i went this route for my battery bank. i have not regretted doing it. at 1110 amp hours each i have plenty of storage. i do plan on 4 battery banks like this in my next home. i will divide the house up into four different breaker boxes with one bank going to a inverter then to one of four braker boxes. i know using a higher voltage would be better, but i like to keep things simple. i'll also run the lighting straight dc in the next house to noy eat up power by inverting it.

    at the momnet i have six of the trojan 2 volt batteries. they set my back about $2300 and that was shipping and handling. not bad in my book.
    Minnesota likes this.
  18. timber

    timber WindyNation Engineer

    I've had very good luck with Deka 8AGC2 190 Ah AGMs.
    Love the maintenance free aspect of glass mat even if they do cost a bit more.
    I think mine are 5 years old now and they hold a charge just as well as the day I got them.
    This may be partially due to the fact that I try to keep them above 80% SOC.
    With limited wind and solar (so far) I do run my 15A IOTA grid powered charger as needed to keep them well charged during low wind or cloudy days.

    I got these for the RV but when not on the road use them as a battery bank for backup and daily use for our laptops and reading lights (so they do see some use).
  19. I guys, looking at going completely off grid and wanting to get the right size battery bank, I have a small 3 roomed cottage in Ireland and use about 6kw/day. I don't have a automatic washing machine but I do have a small under counter fridge and a small tall freezer, a bore hole water pump (1/2hp) that comes on periodically and a central heating pump that runs when my solid fuel central heating in lit. TV/ video/satellite/ set top decoder/ laptop etc. low energy lights.
    Could I have some help in sizing my system from the batteries to the charge controller and inverter.
    I already have 700 watts of solar and a 500 watt wind turbine that are grid tied at the moment and reduce my usage to about 3kw/day.. how much more solar do you think I'll need?
  20. leamywind1

    leamywind1 WindyNation Engineer

    Hello Dave,
    If you are not going to depend on the grid at all any more then you may want to triple your system.
    you need enough battery power to store at least 3 days of power for an example number, that's 18kw and at a 50% depletion rate that is a 36,000 wh battery bank. If you run at a 48vdc voltage that would be a 750AH battery bank at 48v. Double the amp hrs for 24v (1500ah) and triple it for 12v. If you take out 6kw a day of power you would want to put he same back each day at least. With efficiancy factors considered you would want at least a 2-3kw solar system. This also depends on your sun belt rating which you would have to know to calculate the power production vs the amount of panels you would need. I based the general numbers on a 4 hr sun belt rating. The wind turbine, I would not factor in as it is just a bonus.

    Good Luck!!

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