48 Volt forklift battery

SuperGreen
SuperGreen Registered Users Posts: 18 ✭
in Off Grid Solar & Battery Systems #1
Hello all this is my first post.

I just bought a used battery for my off grid system....I have a couple questions can i break down my 48 volt system to 12 volt I do not use much power and want to restore the batteries and thought if i do it in four banks would be the easiet to charge and restore... this is new to me

I am putting up solar panels this summer will have a total of 10 panels 200watts each and then i want to run a 24 volt system I only have a 12 volt invertor now and do not want to buy a 24 volt yet money is hard to come by...

any advice would be great

cheers
john
Prince George BC. Canada
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
    Re: 48 Volt forklift battery

    Welcome to the forum.

    This is going to be one of those "it depends" answers. What it depends on is what you mean by "break down" your 48 Volt battery to a 12 Volt system. Some forklift batteries have accessible intercell connections which will let you pick various Voltages, something like this:

    (-)_____(+12V)____(+24V)____(+36V)____(+48V)

    Not all are configured that way or in such convenient increments.

    If you mean can you run a 12 Volt inverter from a 48 Volt battery through some type of Voltage reducer ... I know of none that could handle the current levels involved.

    Best if you could provide some details about the particular battery. Some of the folk here do run forklift batteries with success (just search the forum for "forklift" to find related threads).

    Of course PG doesn't have any sunlight anyway ... :p
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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #3
    Re: 48 Volt forklift battery

    I would guess you would will not be able to support (have enough Array) the whole battery. Most of the 48 volt batteries are pretty large. Much of any advice would need to know the size of the battery (Amp Hours Like this will be an 8 hour rate and a 20 hour rate would run 20 - 30% more)

    Most fork lift batteries would be reasonably easy to cut up, that said If you want the best bang for the buck it might be worth taking it to a business that professionally rebuilds these batteries explain you want a single 12 volt battery out of this 48 volt and let them choose the 6 best cells and build them into a single battery, they might even equalize the "NEW" battery.

    If you wanted to do this your self, you can check individual cells and see which is carrying the most voltage, Each cell is readily visable, the connects between cells are typically covered with plastic, often/typically they will have a small hole in the plastic so you can stick a probe into the contact.

    Be sure to know what your doing, even half dead and idle for months these large battery have lots or danger!

    Wow I just went to check out NAWS forklift battery section (for an image to hot link / post here) and they have added lots of models!
    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.
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  • SuperGreen
    SuperGreen Registered Users Posts: 18 ✭
    #4
    Re: 48 Volt forklift battery

    Attachment not found.thanks guys great info.....I have to post a great picture of how i got this beat out of my van...they weighed it for me it was 2400lbs not light...but it was a successful mission I got it out and more important did not hurt the van..

    this is what i have it has this information on the sticker
    Battery type 24-85-17
    Number of plates 17
    Charge rate 136
    SP. GR. Range 1.275 - 1.285
    6 hour rate 680 amps
    finish rate 34 amps

    it is in great shape and i used a hacksaw and made it into 2 banks of 12 cells each then i cut 1 into 2 sets of 6 cells
    on the 12 cell side it is 22.4
    1 set of 6 is 10
    the other set of 6 is 11.7

    some cell are low i have not done anything to it yet

    I would really like to be able to use at least one bank of 6 cell and repair redo the rest of the cells take my time and do it right.....i may be nuts just wondering this is all new to me
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #5
    Re: 48 Volt forklift battery

    Oh it can be done. But as you've already found out it's not the easiest thing in the world. Some of these batteries are a tad simpler to work with; designed to have cells replaced. Regrettably yours is of the "monolith" design.

    The cells should be "2 Volts" each. So six will get you 12. Sounds like all the cells are low, so some charging and Specific Gravity checks are the first things to do. Hopefully you haven't just bought a ton of scrap lead.
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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #6
    Re: 48 Volt forklift battery

    Well I was off on the 20-30% and the typical rate...

    On GB batteries, and likely these will be very similar, a 680 AmpHour at 6 hour rate will be a 1072 Amp Hour at a 20 hour rate, which we typically use to describe solar battery banks.

    A 12 volt single string would be a pretty good size for a 2000 watt array. The battery/batteries need attention now, sitting they will self disctruct. If you have some way of charging them that would be a start, Check out the Battery FAQ's
    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.
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  • SuperGreen
    SuperGreen Registered Users Posts: 18 ✭
    #7
    Re: 48 Volt forklift battery
    Photowhit wrote: »
    Well I was off on the 20-30% and the typical rate...

    On GB batteries, and likely these will be very similar, a 680 AmpHour at 6 hour rate will be a 1072 Amp Hour at a 20 hour rate, which we typically use to describe solar battery banks.

    A 12 volt single string would be a pretty good size for a 2000 watt array. The battery/batteries need attention now, sitting they will self disctruct. If you have some way of charging them that would be a start, Check out the Battery FAQ's

    I have a propane generator to run my bottling plant and i have many chargers small med large to charge my semi batteries..
    on the bank of 6 i started charging them now I only had enough dist water for that one tuesday will get more and do the other banks...
    I think i can remove dead cells and the system seems to have had a few changed already it is in very good shape...we shall see.
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  • SuperGreen
    SuperGreen Registered Users Posts: 18 ✭
    #8
    Re: 48 Volt forklift battery

    great input gentleman I filled a couple cells i think to much put my semi charger on the one bank of 6 cells and let it charge for three hours not much time but that is all i could do with my generator until the weekend...it brought the bank up to 12.04volts and over night it dropped to 11.94 but it sat for months this weekend i will charge it for 8 hours any tips i have a large charger i use for my semi it has three setting 12 low 12 high and a 220 amp starting charge i was thinking of 3 hours on full and 5 hours on low is this a good idea... i am only dealing with 6 of the cells to start with so i do not screw things up to bad....but i love it... i am using the beast now to run my computer my Led lights and to watch the news... great start.....

    the beast
    Attachment not found.
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  • keyturbocars
    keyturbocars Solar Expert Posts: 375 ✭✭
    #9
    Re: 48 Volt forklift battery

    SuperGreen,

    Looks like you gave your E350 van a workout! Very creative in using the logs to get the battery out. That is a beast of a battery. I'd like to try to find a good, used forklift battery some time.

    Edward
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  • SuperGreen
    SuperGreen Registered Users Posts: 18 ✭
    #10
    Re: 48 Volt forklift battery
    keyturbocars wrote: »
    SuperGreen,

    Looks like you gave your E350 van a workout! Very creative in using the logs to get the battery out. That is a beast of a battery. I'd like to try to find a good, used forklift battery some time.

    Edward

    I am in the water business and i do carry some weight at times but you are correct i sure felt it.....i sat and drank a whole pot of coffee pondering the best rough it sure worked well amazing what we can do if we need to....
    I bought it for 200 and it has already made me smile nothing better that not giving money to Hydro ....i hate them to put it lightly
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #11
    Re: 48 Volt forklift battery

    You've really got to get all the cells charged up fully as soon as possible or else they're scrap metal.

    We're talking about bringing each 12 Volt section up to 14.2-14.8 Volts and holding it there for at least two hours. The longer they're left uncharged the greater the damage from sulphation.

    Funny, my E250 is The Whale http://kaleidopsyche.deviantart.com/gallery/1293140?offset=48#/d2h1kto :p
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  • SuperGreen
    SuperGreen Registered Users Posts: 18 ✭
    #12
    Re: 48 Volt forklift battery
    Cariboocoot wrote: »
    You've really got to get all the cells charged up fully as soon as possible or else they're scrap metal.

    We're talking about bringing each 12 Volt section up to 14.2-14.8 Volts and holding it there for at least two hours. The longer they're left uncharged the greater the damage from sulphation.

    Funny, my E250 is The Whale http://kaleidopsyche.deviantart.com/gallery/1293140?offset=48#/d2h1kto :p

    can i use my big charger on start to get it up to start...it is 200 amps and i will charge each bank of cells each day i will charge a bank with my propane generator i bottle water and can charge the 12 volt cell banks that way
    thank you for your comment
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #13
    Re: 48 Volt forklift battery
    SuperGreen wrote: »
    can i use my big charger on start to get it up to start...it is 200 amps and i will charge each bank of cells each day i will charge a bank with my propane generator i bottle water and can charge the 12 volt cell banks that way
    thank you for your comment

    Just putting Amps to it is not the solution either, as the Absorb stage of charging is Voltage based and very important to the charge. Give the battery FAQ's a good read through: http://www.windsun.com/Batteries/Battery_FAQ.htm
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  • SuperGreen
    SuperGreen Registered Users Posts: 18 ✭
    #14
    Re: 48 Volt forklift battery

    Hey guys what does a charge rate of 136 mean and it also tells me on the sticker 6 hrs 680amps and finish rate 34 amps
    hope this is not a stupid question i am new but keep in mind i am a sponge and love to learn
    cheers
    john :p
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  • jabb
    jabb Registered Users Posts: 16 ✭
    #15
    Re: 48 Volt forklift battery

    I have 24 @ SBY-85-13. (804 Amp hours at 20 Hr rate.) The charge rate is 45-105 Amps. I am not able to get my SG to 1.285 which is recommended by the Mfg weekly.
    I think my settings may be too low and too short. I have been equalizing every 2 weeks trying to increase the SG.
    GBI MFG Settings:
    Float is 2.21
    Absorption is 2.35 for 1 hour
    Equalize is 2.38 for 4 hours
    The voltages appear to be 100% all the time on my Flex Net DC monitor.
    Does anyone have experience with these or similar Forklift Battery settings?
    Thanks, any help will be appreciated.

    My system is 2 MX60 controllers with 4880 watts of solar power, a Hub 4 and Mate with a Flex Net DC monitor. The inverter is a SW5548 and the generator is 11kw Isuzu diesel. I use a 48v pulse charger on the batteries at all times.
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  • SuperGreen
    SuperGreen Registered Users Posts: 18 ✭
    #16
    Re: 48 Volt forklift battery
    SuperGreen wrote: »
    great input gentleman I filled a couple cells i think to much put my semi charger on the one bank of 6 cells and let it charge for three hours not much time but that is all i could do with my generator until the weekend...it brought the bank up to 12.04volts and over night it dropped to 11.94 but it sat for months this weekend i will charge it for 8 hours any tips i have a large charger i use for my semi it has three setting 12 low 12 high and a 220 amp starting charge i was thinking of 3 hours on full and 5 hours on low is this a good idea... i am only dealing with 6 of the cells to start with so i do not screw things up to bad....but i love it... i am using the beast now to run my computer my Led lights and to watch the news... great start.....

    the beast
    Attachment not found.

    Hi guys any tricks to removing the lead caps joining the cells must be some way to remove them ...maybe not
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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #17
    Re: 48 Volt forklift battery
    SuperGreen wrote: »
    Hi guys any tricks to removing the lead caps joining the cells must be some way to remove them ...maybe not

    Appears they are soldered on to the lead caps, Looks like triming them back then tapping them might be in order, perhaps even cutting at they cell case and drilling through and using sheet copper to make new connections.

    Link to assembly process.
    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.
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #18
    Re: 48 Volt forklift battery

    I saw a picture somewhere of the dis-assembly and they used a hole saw to cut around the strap. I think you'd want the center drill short, just long enough to get the saw to bite. You'll have a hole to tap, so you can hook up with a bolt. The straps are slipped over the post and soldered in place.
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  • SuperGreen
    SuperGreen Registered Users Posts: 18 ✭
    #19
    Re: 48 Volt forklift battery
    Photowhit wrote: »
    Appears they are soldered on to the lead caps, Looks like triming them back then tapping them might be in order, perhaps even cutting at they cell case and drilling through and using sheet copper to make new connections.

    Link to assembly process.

    thank you
    I tried a small chisel and lightly tapped it and got one to move about a quarter inch and wanted to make sure i was not damaging the post seems to be ok just do not want to ruin the beast

    cheers
    john
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