using a forklift battery

ozarkgemozarkgem Registered Users Posts: 21
I did a search and didn't see anything about using a forklift battery. I have 3kw of panels, Magnum 4024 pure sine wave and thinking of using a 24 volt
750 amp hr forklift battery. I have not installed anything yet. I still need a charge controller. I also have a Kubota 6.5 kw gen set as a backup. I am going totally off grid with this system. I just built a new cabin with off grid in mind. I may need to add more panels for the AC. I am rather new at this. I
have played with solar in my barn and another cabin I had . So I may have lots of questions later on. So my main question is , has anyone used a forklift battery? I can get one that is 2 yrs old for $750.00. I have the equipment to move it with so that is not a problem.
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Comments

  • BB.BB. Super Moderators, Administrators Posts: 30,486 admin
    Re: using a forklift battery

    Forklift batteries are fairly popular. They are very rugged, long life (upwards of 15-20 years), large AH capacity, so you don't usually have to parallel battery strings.

    The downside is they tend to use more distilled water and are a bit less efficient/higher self discharge.

    Our usual suggestion is 5% to 13% of battery 20 Hour rating (i.e., a 100 AH battery needs 5-13 amps of charging current). For a forklift battery, I would suggest more charging current, closer to 10% to 13% of rated power to make up for less efficiency/higher self discharge (especially when batteries get old).

    Poster "adas" has been getting very used forklift batteries, cutting out failed cells, and using them in his off-grid fabrication business (Hawaii) for quite a while. Has been very happy. You can search for his posts/threads by clicking on the link.

    Also, if you have problems finding posts using the forum search tool--You can use Google with the "site:wind-sun.com" tag:
    • Forklift battery site:wind-sun.com

    And you will get a 1,000 hits or more.

    So, charging a 750 AH @ 24 volt battery bank with solar panels:
    • 750 AH * 29 volts charging * 1/0.77 panel+controller derating * 0.05 rate of charge = 1,412 watt array minimum
    • 750 AH * 29 volts charging * 1/0.77 panel+controller derating * 0.10 rate of charge = 2,825 watt array nominal
    • 750 AH * 29 volts charging * 1/0.77 panel+controller derating * 0.13 rate of charge = 3,672 watt array "cost effective maximum"

    Charging current from a genset is also recommended to be ~5% to 13%, but you can go upwards of 25% or so maximum (note, high charging currents and deeply discharged batteries can overheat and should be limited to ~13% maximum rate of charge unless you have a remote battery temperature sensor to reduce charging voltage when battery bank gets hot--Also, remember that batteries do not like to be hot, it will reduce the battery's life).

    Do you have an AC battery charger picked yet? (around 100 amp charger would be close to 13% rate of charge).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: using a forklift battery
    ozarkgem wrote: »
    I just built a new cabin with off grid in mind. I may need to add more panels for the AC. I am rather new at this. I
    have played with solar in my barn and another cabin I had .

    Is this new cabin too far from the grid to be connected economically, or is the off-grid part just a choice?
    SMA SB 3000, old BP panels.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: using a forklift battery
    ozarkgem wrote: »
    I did a search and didn't see anything about using a forklift battery. I have 3kw of panels, Magnum 4024 pure sine wave and thinking of using a 24 volt
    750 amp hr forklift battery. I have not installed anything yet. I still need a charge controller. I also have a Kubota 6.5 kw gen set as a backup. I am going totally off grid with this system. I just built a new cabin with off grid in mind. I may need to add more panels for the AC. I am rather new at this. I
    have played with solar in my barn and another cabin I had . So I may have lots of questions later on. So my main question is , has anyone used a forklift battery? I can get one that is 2 yrs old for $750.00. I have the equipment to move it with so that is not a problem.

    Welcome to the forum.

    There must be fifty-eleven threads on here that mention forklift batteries. Like Bill said, the search goes easier using the google 'site' restriction. :roll: Those that use them like them, although they take a bit of getting used to. Apparently you can overcome the biggest problem with them, which is the sheer mass.

    Instead of jumping in to using a forklift battery, guessing at a charge controller, and wondering if you need more panels ... define the loads.
    You've got to figure out how much power you need/want first, then determine how bast to do it. The forklift battery may or may not be the right answer for you.
    Buying a Kill-A-Watt and measuring the power consumption of things you actually want to use will be a big help.

    Otherwise, 3kW of panel is overkill for a 750 Amp hour battery. On 24 Volts you're looking at peak current around 96 Amps, and that is more than any one charge controller can handle. It's also enough array for 6kW + of power per day, which is a lot for an off-grid cabin (about double what I use).

    To reiterate, get the loads figured out first: the system's design and performance is dependent on that.
  • ozarkgemozarkgem Registered Users Posts: 21
    Re: using a forklift battery

    Thanks for the great info. Let me start from scratch. My cabin is 20x30 with a 10 x 20 loft. I have 8" wall's, 6" of insulation in the floor and 6" foam
    on the roof. It has vaulted ceilings. I will have 2 110 ac units. one pulls 6 amps the other 8amps(i think). I have a 110v 19 gal water heater with a
    1500 watt heater. My thinking on that was I already had the water heater. I gave $50.00 for it and it was only 6 months old. A gas WH would cost
    about 650.00 plus a propane bill every year So I took the difference and bought panels. I am also putting a tempering tank by the WH (loft) so that
    the water that goes into it will be at room temp. I may do a solar WH later. I plumbed for it. I tested the WH with the gen set and it took 1 hr to get the
    water hot from room temp. The fridge will take about 400 kw per yr according to the tag. The washing machine about 250 KW per yr. The dryer will be a
    clothes line in the summer and a gas dryer for winter. Not sure on the KW for it. Lets say 200 Kw. LED and florescent lites. No tv. No idea on the laptop.
    Water pump is 1/3 hp shallow well. So say 100 kw for the yr. The the normal micro wave , toaster ,coffee maker and misc kitchen stuff. I live by my self
    so not much power will be wasted. I could have ran power for about $2500.00 plus the "convient" monthly bill. I was able to get my inverter for $600.00 from a repair place. The owner didn't pick it up so I got it for the repair bill. The panels were a buck a watt. The battery is 750.00. If I take the tax credit
    the panels will be .70 watt. I am semi retiring next yr so I am trying to cut my monthly bills as much as possible. I like the challenge of not relying on someone else. I am 95% done with the cabin and I have about $6200.00 in it so far. yes 62 hundred not 62 K.

    Oh yea the charge controllers. I was thinking 2 C 60 controllers. I like redundency. I am not sure about equalizing the batteries though. Maybe a
    forklift charger with equalize setting running off the gen set. One more thing on the AC. The reason I was going with 3k on the panels was to run both
    AC's all day long and use one at night. So tell me where I am going wrong and how to improve what I am doing. When I am done I will do video and have
    my kids post it on youtube. Hope that cleared some things up.
  • ozarkgemozarkgem Registered Users Posts: 21
    Re: using a forklift battery

    I tried to find user Adas in the advance search. I also used the words "forklift battery" and got nothing. What am I doing wrong?
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: using a forklift battery
    ozarkgem wrote: »
    I tried to find user Adas in the advance search. I also used the words "forklift battery" and got nothing. What am I doing wrong?

    The search tool is pretty limited. But the name "adas" in the post about him is a link to his member page, http://forum.solar-electric.com/member.php?1074-adas, and if you use the "Show recent Posts" link from there it should get you started.

    "forklift battery" is to be used in the specific Google search pattern shown, not in the search tool built into this forum.

    Paste "Forklift battery site:wind-sun.com" into Google.
    SMA SB 3000, old BP panels.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: using a forklift battery

    In off-grid terms you're doing just about everything wrong. :p

    Electricity is a poor choice for heating anything, especially when it's being supplied at a cost about ten times that of a utility grid. A/C is another monster power user. The investment in grid connection and the on-going monthly charge would be cheaper than constructing an off-grid system that can supply that kind of power. Really. You are looking at more money for the solar electric than you've got in the cabin - about X3 in fact.

    If you're determined anyway, you need to analyze your power use on a daily basis, as that is the common mode for off-grid: recharge daily. You have to have an inverter large enough to supply the maximum cumulative load and a battery bank that can back it up. Without doing the fine math it looks like your electric consumption would be in the "normal small household" range which is around 15kW hours per day. Honestly you are probably in the 7kW array range, not 3kW.

    One helpful hint: don't spend the money on even one C60 charge controller. They are not the best. You should be considering either a MidNite Classic or Outback FM controller.

    We did some testing on A/C units here, btw. Some proved to be better than others. The mini-split type are most efficient. In one instance I found a 11,000 BTU portable unit used only slightly more power than a 5,000 BTU window unit. Look at the threads in the energy use and conservation area. The more you can get your usage down, the cheaper and off-grid system will be.

    BTW, if you went with utility hook-up do they allow grid-tie? You might want to look into that; have the solar off-set your power use, use the grid as your 'battery', and perhaps even make a dollar on selling surplus production to the company.
  • ozarkgemozarkgem Registered Users Posts: 21
    Re: using a forklift battery

    thank you I will give it a shot
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: using a forklift battery

    Yes the search function on the site doesn't work well.

    There will be some links to similar posts at the bottom of this thread page, and you can use the Google 'site' key to search better:

    forklift site:wind-sun.com

    Get's this result page: http://www.google.ca/#hl=en&output=search&sclient=psy-ab&q=forklift+site:wind-sun.com&oq=forklift+site:wind-sun.com&gs_l=hp.3...897.8106.1.9600.26.23.0.0.0.0.2250.16578.5-13j1j1j2j1.18.0.les%3B..0.0...1c.1.e5mW-O-T5t0&psj=1&bav=on.2,or.r_gc.r_pw.r_qf.&fp=b04ec322ebd918c&biw=1366&bih=655
  • ozarkgemozarkgem Registered Users Posts: 21
    Re: using a forklift battery

    I looked at the mini splits and the ones I saw were 220V. The main reason I want to go off grid is I don't want power lines going to my house. I have to maintain a 30'(each side) of the power line . To me it says someone lives there lets go get their stuff. Under ground was double the cost plus I had to furnish the trench. Pretty rocky here so
    that would be expensive. guess I could learn to live without ac or run my gen set on Bio diesel. It cost about .10 per hr to do that. I will check into the charge controllers.
  • BB.BB. Super Moderators, Administrators Posts: 30,486 admin
    Re: using a forklift battery

    There are a few inverters (in the ~4-6kW range) that offer 120/240 VAC split phase "native" (no extra hardware). And there is always the step up transformer (not a great solution--but if nothing else, it can work).

    There was the Sanyo Mini-split that was a 120 VAC unit--but that just went away a few months ago when Panasonic took them over.

    A few other vendors do have 120 VAC mini-splits--But not many.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: using a forklift battery

    The nice thing about AC is that the consumption matches solar radiation (in my part of the world anyway). So I've been running our mini-split every day throughout the summer and still had power to spare with a 2.8kW array. Running both an electric water heater and 2 AC units might just be doable on good summer days from 3kW, but forget about it in spring, autumn and winter.
    Given the price you paid for those panels and the cost of diesel, it may pay off installing more solar.

    Regarding the forklifts, I've only had mine for a year, so can't comment on how long they'll last. Mine use very little water, I top them up every 4 months or so with 7 Litres of water. The batts you get in the US might use a different chemistry so may gas more and need more water. It's a pity you've already committed to the inverter because the size of system you're talking about would have been better at 48V. It's not too serious though, you'll just need to buy more charge controllers.
  • ozarkgemozarkgem Registered Users Posts: 21
    Re: using a forklift battery

    I was thinking of getting another 1 KW of panels. The water heater and AC will not be running at the same time. I have a switch on the WH. 48 V would be nice also. I will keepan eye out for another Magnum as the one I have is stackable. I want to keep it as simple as possible.
  • ozarkgemozarkgem Registered Users Posts: 21
    Re: using a forklift battery

    Another question. With 3K of panels and 5 hrs of Sun doesen't that make 15KW for the day? I know there is the loss factor to account for also. I am hoping with the inslulation I have it will cool easy. I am insulating the water heater so I will only turn it on once a day.
    Thanks for the info on the controllers. That is why I ask questions. I have a friend who has the Outback. I have a hard time programming things so I was wanting to
    stay simple.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: using a forklift battery
    BB. wrote: »

    There was the Sanyo Mini-split that was a 120 VAC unit--but that just went away a few months ago when Panasonic took them over.

    A few other vendors do have 120 VAC mini-splits--But not many.

    -Bill

    The Sanyo 120 volt unit is gone? That sucks :(
    Re other 120 volt brands, year ago I got a Fridgaire 120 volt mini-split (heard later that many Fridigaire products were unreliable) but so far I've been VERY pleased with it. This past Summer we had the hottest weather, the whole season long, on record, and most days I ran it in AC mode all day, as long as the sun was shining. Don't know what I would have done without it. Efficiency and power consumption? Far, far better than any window AC, and by carefully adjusting the thermostat, I could control it's power draw, holding it at roughly 400 watts max, but many times it was still providing cooling with only 150 watts. That truly amazed me! Also amazing was, unlike window AC, the slow ramp-up of power consumption on startup. Very easy on the inverter. Initially, my idea was to only use it Spring and early Winter for heat when it wasn't cold enough for the wood fire and had no intention of using it as AC, but one very hot summer day, in desperation, I tried it in AC mode and nearly fell over when I realized how little power it used compared to my expectations, and that I could run it all sunny day long and still get my batteries topped up in spite of also running 2 chest freezers and an upright freezer converted to fridge! I just cannot get over what my off-grid system will handle with proper load management. Far beyond my wildest dreams! Of course it helps that initial expectations were not too high :D
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: using a forklift battery
    ozarkgem wrote: »
    Another question. With 3K of panels and 5 hrs of Sun doesen't that make 15KW for the day? I know there is the loss factor to account for also. I am hoping with the inslulation I have it will cool easy. I am insulating the water heater so I will only turn it on once a day.
    Thanks for the info on the controllers. That is why I ask questions. I have a friend who has the Outback. I have a hard time programming things so I was wanting to
    stay simple.

    For battery-based systems the loss factor is huge: nearly 50%. This is largely because as the panels reach their peak output at midday the batteries have done most of their charging so there's no place for the power to go as they only need 'so much' and not all that the panels can produce.

    This is when you start to experiment with "load shifting": selectively running things that can make use of the power that would otherwise go unharvested. For example it's when I turn on my water pump and fill up the tank and turn on the septic pump and empty the tank. Both are big users. Microwaving lunch is good too. :D
  • PhotowhitPhotowhit Solar Expert Posts: 5,169 ✭✭✭✭
    Re: using a forklift battery

    There is Good, bad and ugly...

    Are you in the Ozarks? I'm in Central Missouri and bought a forklift battery last year and will be attempting what you are Setting up this fall (I should be out working now!)

    Good; Your a scrounger, you've bought cheap, love the deal on the Magnum 4024! The forklift battery in a heavy use warehouse could be left with half a life if well maintained, but likely still a good deal, ask them why they are selling, if it has shown reduced life already that might be telling... Forklift batteries are normally defined by a 6 hour discharge rate. If it has 750Amps at a 6 hours discharge rate it might well have 1200 at a 20 hour rate (the rate normally used for solar aplications) There is a spec sheet Here that should offer comparisons with both rates listed.

    In central Missouri I normaly have sun with heat, you may have more clouds with the Hilly area. I found that I will be close to utility costs in my rough estimates in this thread. but my utility charges $25 a month before I buy electric. Do you have 8" of insulation in the walls or is it a block wall? 6" of foam below the framing or sprayed in? ^" of foam should be @R30 but if you have wood that traversis the foam it will transmit the heat a bit. If you have it well insulated I think you'll be close. Is the cabin built in the shade or out in the open, this also will make a difference in the amount of A/C you'll need.

    On the water heater, an hour to heat 19 gallons is pretty fast, 1500 watt elements are not the norm for that large a water heater, so I question if all is correct with the info. I too, will try to use an electric small water heater off solar, this is NOT recomended or natural, I'll use a timer and heat for 30 minutes at a time while the sun is shining and use a 6-10 gallon water heater. Please note that the inrush water temperature will make a difference if it's 75 in the summer and 35 in the winter the load will be greatly different, the prewarming tank will help a bunch!

    The Midnite Classic Lite Charge controllers are as cheap as the 60 Amp MPPT charge controllers and have presets and can be use without special setups, we haven't discussed what type of panels you purchased but since they were cheap I would assume they are NOT 24V nominal panels. Some ignorant Solar retailers sell panels as 24 Volt that are NOT, if you wanted to use a 24V PWM charge controller you need a VMP of around 35 volts, unless they are this high they won't reach charging of equalizing voltage.

    I suspect you'll want more array, but your close if your well insulated, I figured I would be close at 4 KW array, but scrounged another 2+ KW of panels on a good deal...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • mike95490mike95490 Solar Expert Posts: 8,752 ✭✭✭✭✭
    Re: using a forklift battery

    Water heating, look at the Rheem Soar Aide roof top system. Or anything but PV electric. Direct collection is several times more efficient than PV (only 14% efficient)
    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 ,

  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: using a forklift battery
    mike90045 wrote: »
    Water heating, look at the Rheem Soar Aide roof top system. Or anything but PV electric. Direct collection is several times more efficient than PV (only 14% efficient)

    If you have to heat water (or air for that matter) with PV electric, look at using a heat pump instead of a resistive heater to get 3 times the heat per PV watt.
    SMA SB 3000, old BP panels.
  • solar_davesolar_dave Solar Expert Posts: 2,362 ✭✭✭✭
    Re: using a forklift battery
    The Sanyo 120 volt unit is gone? That sucks :(
    Re other 120 volt brands, year ago I got a Fridgaire 120 volt mini-split (heard later that many Fridigaire products were unreliable) but so far I've been VERY pleased with it. This past Summer we had the hottest weather, the whole season long, on record, and most days I ran it in AC mode all day, as long as the sun was shining. Don't know what I would have done without it. Efficiency and power consumption? Far, far better than any window AC, and by carefully adjusting the thermostat, I could control it's power draw, holding it at roughly 400 watts max, but many times it was still providing cooling with only 150 watts. That truly amazed me! Also amazing was, unlike window AC, the slow ramp-up of power consumption on startup. Very easy on the inverter. Initially, my idea was to only use it Spring and early Winter for heat when it wasn't cold enough for the wood fire and had no intention of using it as AC, but one very hot summer day, in desperation, I tried it in AC mode and nearly fell over when I realized how little power it used compared to my expectations, and that I could run it all sunny day long and still get my batteries topped up in spite of also running 2 chest freezers and an upright freezer converted to fridge! I just cannot get over what my off-grid system will handle with proper load management. Far beyond my wildest dreams! Of course it helps that initial expectations were not too high :D

    these guys have some 120V units
    http://www.friedrich.com/products/residential/built-in/ductless-split-systems/wall-mounted/model-specifications
  • ozarkgemozarkgem Registered Users Posts: 21
    Re: using a forklift battery

    I timed the water heater using the gen set. Set about 125 degrees. My panels are 39v open voltage. 8" bat in the walls, 6" bat in the floor and 6" sheet foam on the roof. I get the batteries in Springfield. He says they are only a few yrs old. Told me he has sold several for solar installations. I am close to Stockton Lake. I plan on adding another KW soon.
  • PhotowhitPhotowhit Solar Expert Posts: 5,169 ✭✭✭✭
    Re: using a forklift battery

    VOC is not important, typically VMP (under load) is what you want, 39V will make that around 31 volts, really not high enough to use a PWM charge controller, there will be some loss on before the current gets to the batteries also voltage decreases when the panels are hot, so equalizing likely won't work and charging would be iffy at best, I think I use @29.2 and float at 27.6

    Did you get the Amp Hours at the 6 hour or 20 hour rate? or What are the size of the batteries?

    I would be interested my self, I had planned on moving my new fork lift battery to the new system, but I can borrow a truck and make it to springfield, MO (I'm assuming, Springfield AK has about 200 souls) If he has a ready source. I can use a larger battery than the 800 Amp(20hr rate) 24V that I planned on using. I even have time and availablity the end of October.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • ozarkgemozarkgem Registered Users Posts: 21
    Re: using a forklift battery

    my mistake. Voc is 44.5 VMPP is 36. I haven't picked up the battery yet. Have to get the dozer going to clear off a place to put everything. Are you totally off grid?
    I guess the one battery is not enough?
    I can always change out my WH for a gas one. I plumbed in a gas line just in case. I could get a gas refer also but I like my ice in the summer time. If need be I can run the
    washing machine on the gen set. Its the AC that I will have to work on. Maybe I will just spend the summers in AK. That would be cheap!
  • Ralph DayRalph Day Solar Expert Posts: 913 ✭✭✭✭
    Re: using a forklift battery

    I run my Mitsubishi (240vac unit) off my SW4048 120vac inverter. All you need is an autotransformer to bring 120 up to 240 (it also transforms 240 to `120 in other applications). The parasitic load of the transformer is about 8 watts per hour, the standby load of the minisplit varies from 15 to 45 watts per hour. I have a breaker on the transformer and a dpdt switch before the minisplit load (and a plug/outlet to power it all up...can and is shut off most of the time).

    Both Xantrex/Schnieder and Outback (probably others) make autotransformers. Not a really expensive item compared to a new split phase capable inverter, or another inverter stacked.

    Ralph
  • PhotowhitPhotowhit Solar Expert Posts: 5,169 ✭✭✭✭
    Re: using a forklift battery
    ozarkgem wrote: »
    my mistake. Voc is 44.5 VMPP is 36. I haven't picked up the battery yet. Have to get the dozer going to clear off a place to put everything. Are you totally off grid?

    I'm totally off grid at my cabin, and at my new place, I hope to be this fall. The question about the size of the battery in 20 hour rate, Amp hours is an important one in sizing your system. Living "off grid" for me, has to do with knowing how much energy your using. Since your single some things won't be much bother at all, washing machine use is based on a family of 4 with @ a load per day. your more likely to have a load every 4 days. you'll want to 'load shift and do this sort of thing during the daytime, making it easier on your battery.

    Your "normal... microwave , toaster, coffee maker and misc kitchen stuff..." will all need to be looked at as you adjust to off grid living. I don't drink coffee, but that will be a heavy load when your system is just getting going, toaster also, I regularly 'nuke' my oatmeal in the morning and that's a heavy load but for a very short time.

    Other things will no longer be set and forget, I wouldn't leave the hot water heater running on thermostat, run a 'grey box' timer at least or better manually turn it on when you reach 'float' in the afternoon. A good opportunity load.

    You appear to be well setup for running an A/C, the floor insulation is minimal, but 8" in the walls is great! Still I don't think I'd try to run it from the thermostat with out knowing where you stand with your battery. My cabin can likely run 24/7 on thermostat, but it is a tiny building 10x16x 14(tall) (6" walls, 8+ inches in the floor, built in the shade) with about a 1700 watt array feeding a 800Ah battery. but I don't, It's built in the shade and I set a timer to have the A/C come on and hour or so before I get home and I run the A/C window unit on economy mode. It has gas hot water and public water. The A/C and a fridge is about all it runs.

    Those panels will run on a PWM charge controller for a 24V system, it won't be as efficient as a MPPT type controller and for the amount of array you have it is probably reasonable to go ahead with a MPPT type charge controller or 2. The Midnite classic lite has presets (you have to set them once with dip switches) If you want to check on your battery status you could use a trimetric meter. You can follow the link in my previous post, if you want simple and cost effective, I think that is the way to go, then again it's the way I went. If you would prefer having more information the outback charge controllers can work with their own metering system and provide a bit more info.

    The Classic 150 will handle up to about 2500 watts on a 24V system. We haven't talked about the distance from your array to your battery bank. In setting up a system this is important, as you look at voltage drop over distance.

    The size of your battery is important, ask the seller if the Amp hour rate is a 6 hour rate or a 20 hour rate, or ask for the type of battery, all forklift batteries I've seen have this info on the side, likely an OSHA thing. If it just has one Amp hour rating this will be a 6 hour rating and the 20 hour rate will be considerably higher. these rates have to do with the rate of discharge, if it's rated at 750 Amp hours it will take a 125 amp hour load for @6 hours, this type of battery is normally used this way. in solar applications you'll be discharging the battery much slower and it may well be closer to 1200Amp hour for 20 hours or take a 60 amp load for 20 hours. Same battery, this is the rate we 'normally' use when discussing solar battery banks. You can use the link I provided in the earlier post to compare your battery to those listed to get an idea of the true size for solar applications.
    ozarkgem wrote: »
    I guess the one battery is not enough?

    All depends on the size of the battery...
    ozarkgem wrote: »
    I can always change out my WH for a gas one. I plumbed in a gas line just in case. I could get a gas refer also but I like my ice in the summer time.
    If you have real data saying you can heat water it in an hour, IMO it's worth a try, again I'd have it shut off after heating and do this as an opportunity load. I think a fridge is cheaper to do off grid at this point.
    ozarkgem wrote: »
    If need be I can run the washing machine on the gen set. Its the AC that I will have to work on. Maybe I will just spend the summers in AK. That would be cheap!

    I don't think the washing machine is a problem, I've been drying on a drying rack inside, I got use to it in the winter and at worse it takes a couple days for jeans and towels. Front load washers use the least amount of electric.

    I think you'll find it rewarding to figure out the solar, I came from 'way off' the grid having started very small and growing into the larger system, not easy and I ended up with lots of spares. Coming from the grid, I suspect you'll find it challenging to live within the amount of electric you've stored.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • ozarkgemozarkgem Registered Users Posts: 21
    Re: using a forklift battery

    I was unable to open the PM. I will have to get my 3 yr grandson to open for me. LOL
  • ozarkgemozarkgem Registered Users Posts: 21
    Re: using a forklift battery

    Thank you, I will check into it.
  • Volvo FarmerVolvo Farmer Solar Expert Posts: 209 ✭✭✭✭✭
    Re: using a forklift battery
    Photowhit wrote: »

    Front load washers use the least amount of electric.

    I'm not so sure about that. Front load washers use less water, and subsequently, less hot water. They spin more water out of the clothes, but I'm not so sure that their electricity use per load is substantially different than a top loader. The majority of the difference we see on the yellow Energy Guide labels is due to the heating of water.

    I test washing machines all the time. Maybe some day I'll hook up a Kill-a-watt and measure the difference. Now I'm curious!
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: using a forklift battery
    I'm not so sure about that. Front load washers use less water, and subsequently, less hot water. They spin more water out of the clothes, but I'm not so sure that their electricity use per load is substantially different than a top loader. The majority of the difference we see on the yellow Energy Guide labels is due to the heating of water.

    I test washing machines all the time. Maybe some day I'll hook up a Kill-a-watt and measure the difference. Now I'm curious!

    now that would be interesting to hear results on.
  • BB.BB. Super Moderators, Administrators Posts: 30,486 admin
    Re: using a forklift battery

    I have an older Fisher & Paykel washer/gas dryer set and I use about 0.250 kWH per load (each machine). They are direct drive DC Stepper motor type and don't have high surge current either.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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