Why not just use forklift batteries for Off Grid?

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softdown
softdown Solar Expert Posts: 3,824 ✭✭✭✭
in Off Grid Solar & Battery Systems #1
Everything that I read seems to indicate that they are the best in about every respect. Most important being longevity. This is assuming that you can fit them into your battery space. Being available in 24 volt and 48 volt configurations makes wiring and maintenance so very much simpler for many of us.

Often referred to as traction batteries, they seem to be the best of the best. I have seen reports of realistic and strong 15 plus year life spans - without babying them.
First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #2
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    Re: Why not just use forklift batteries for Off Grid?

    Yep, I'm pretty happy with my forklifts. But they do have some shortcomings:

    - To squeeze the most energy in the smallest space they come with a relatively high SG, around 1.28 which isn't ideal for longevity. Lower SG would be better.
    - Also because of space limitations there isn't a lot of extra space above the plates for the electrolyte. I generally add water every 3 months.

    IMO the "best of the best" are the OPzS style stationary batteries like these: http://www.enersys.com/PowerSafe_OPzS_Batteries.aspx?langType=1033
    Low SG, and a LOT of spare electrolyte above the plates, meaning yearly or less watering intervals. They use them over here for most medium to large off-grid installs and for remote telecom sites.
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  • softdown
    softdown Solar Expert Posts: 3,824 ✭✭✭✭
    #3
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    Re: Why not just use forklift batteries for Off Grid?

    I didn't get a quote from the site that you linked. How do they compare cost wise?

    I'm really looking for the best battery solution for the buck. I think that holds true for many of us.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,447 admin
    #4
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    Re: Why not just use forklift batteries for Off Grid?

    If you divide their size by life--Fork Lift batteries look pretty nice.

    Downsides:
    • Use more water (flooded cell versions)--DI water can be a cost/difficult to obtain factor
    • Less efficient (can lose as much as 2% per day near end of life)
    • Heavy. Need overhead crane/concrete floors and a pallet jack to move around
    • Even if you can get "bare cells", many still need an outside metal box/container for structural support
    • If you have an "oops" (discharge dead, fill with non-DI water, etc.)--Very expensive oops
    • Many batteries can have individual cells replaced--Sort of nice compared with 12/6/4 volt batteries where a bad cell ruins the entire battery
    Not the worst set of drawbacks... But something to think about.

    With the lower costs of solar arrays and how long they lasts--Not a bad solution.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • H2SO4_guy
    H2SO4_guy Solar Expert Posts: 213 ✭✭✭
    #5
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    Re: Why not just use forklift batteries for Off Grid?

    I went with used Panasonic stationary batteries. 2 strings of 1040 AH (@ 8 hr rate) for a total of 2080 AH @ 48 volts DC. These are amazing! 17 days with only 2 days of some sun and even though I only heated with them for a few days, the rest I used propane, the lowest I ran them down was 49.5 volts under load. Unless there is not much sun I run all electric except for propane water heating. I have had these for about 15 months now and they run AC, heating, and everything I throw at them. When I got them I bought 56 cells so I have 2 strings and 6 spares. That should make 1 string last a very long time. They are all the same age and everything, so we will see how long thy last. I have about $2000 in batteries and that includes 12 group size 8D (3 strings of 165 AH @ 48 volts DC for a total of 495 AH) not counting the lead for trade in.

    I thought I would go with a forklift battery, but the downfall is that there is not a good way to get extra cells for a reasonable price. You can get them, but it is a crap-shoot. Used forklift batteries were going for around $1500 and who knows how long they will last and there are no spare cells of the same age and condition.

    Bottom line: For about $2000 I have about 2500 AH @ 48 volts DC with spare cells. It works for me, but as Vic says, YMMV.

    Good luck and let us know how it works out.
    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
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  • cdre
    cdre Solar Expert Posts: 78 ✭✭
    #6
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    Re: Why not just use forklift batteries for Off Grid?

    H2S04, where did you pick up your batteries? What model are they?
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  • H2SO4_guy
    H2SO4_guy Solar Expert Posts: 213 ✭✭✭
    #7
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    Re: Why not just use forklift batteries for Off Grid?

    I have Panasonic stationary batteries AGM sitting on their side. Can't remember model, but I can look over the weekend if you like. It is always a crap-shoot on what they get in used, but I brought them cookies for 12 weeks and when they got a big load of these batteries I was ready with lead trade-in for weight and cash.

    I would suggest finding where the last stop is before the trucks take the batteries to the smelter and work out a deal with those people. Many battery places send their stuff to the guys I deal with. There is typically a battery seller who gets a contract to recycle big batteries. Just be ready when they come in. I am not above shameless bribing. (Cookies work very well BTW)

    Good luck and let us know how it works out.
    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
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