New here, have battery question.

GUSRENTIT
GUSRENTIT Registered Users Posts: 14
Has anyone tried using two or more 48V fork lift batteries? Like the huge 48V 2500 LBS ones? Tied to PV or wind gen, the specs look real good on the batts, they can be discharged quite a bit. Next, I want to go off grid, how do I figure how big of a PV or Wind Gen system I need to equal my current average on grid 1100 KWH a month use. Not crazy, just asking for some base line info. Every time I ask "those who know" I get told they do great off grid, then I find out that they live in a 12' x 12' house with propane everything and a 6 cu.ft. fridge, 2 LED lights, and a laptop, and they look at me like I'm some kind of nut, trying to live in a normal house. Thanks!
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Comments

  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    I live off grid, and use a moderate sized forklift battery @1100 lb 24V. They are a bit different and require a bit more attention, use more water in general and require equalizing monthly..

    I live in a 900 sqft Tin can (Mobile home) I would suggest if you want no compromise to forget about solar, or do a grid tied system. 1100 KWH a month is a lot of energy even living in the sunny south west! This will require a rather huge system. Even if it was even across the month, and I'll bet it's not! you're looking at 1100 ÷ 30 = 36+ KWHs a day and if you intend to store the energy on site just preparing for a single cloudy day would require a battery of 72 KWH's storage. My battery has around 15 KWHs of storage...

    I heat with wood and run an a/c in the summer in a single room, though I'm large enough to at least run a minisplit as well as an opportunity load, I do heat water from the system as well though.
    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.
  • GUSRENTIT
    GUSRENTIT Registered Users Posts: 14
    Photowhit, I live in a 1500 sq ft mobile home, on 46 acres, and the only extra is a 1/2hp water pump, whole house a/c 11000btu, I heat with wood, but in the winter I use electric heat to heat 5 dog kennels, today it got to 104*F and tonight it will be 50*F, in the winter it can get to over 70*F during the day, and -10*F @ night here, last year I had 2 days of 119.5*F . When I move to Arkansas the new place will be a 2400 sq ft. quonset, but the temps should be more even. But we don't live a very high life here, and my lows are around 800 KWH and my high has been 1200 KWH, and if I kick on my mig welder, well the sky is the limit. It's just the wife and I and 12 dogs, 2 computers, one tv, propane stove, propane hot water, electric dryer. Not sure where I can cut back a whole lot. But I'm open to any advice. I have friends that use over 5000 KWH a month around here, they have electric bills of $700 a month, and that is crazy!
  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    GUSRENTIT wrote: »
    I have friends that use over 5000 KWH a month around here, they have electric bills of $700 a month, and that is crazy!

    And if these friends tried to go off grid with that consumption it would cost them thousands a month. Grid power is CHEAP compared to battery-based renewable energy systems.

    Generally, it costs less to conserve a kilowatthour than to generate and store a kilowatthour. The huge amount of money you will spend building a massive off grid system would be better spent on efficiency, so you didn't need such a massive system.
    GUSRENTIT wrote:
    Has anyone tried using two or more 48V fork lift batteries? Like the huge 48V 2500 LBS ones? Tied to PV or wind gen, the specs look real good on the batts, they can be discharged quite a bit.

    In a forklift, those batteries are commonly discharged to 20% SOC. That won't work in a renewable energy system. When you discharge a battery that deeply it needs to be fully recharged immediately.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    A lager place will generally have larger energy uses, and, depending on where you are in Southern Colorado, Arkansas will likely have more cloudy days, but the dogs won't need heat...

    Lots of ways to conserve, You just need to look!

    Mini Split A/C's are very efficient.

    Earth contact homes use much less energy, using the earth as a thermal mass, the base temps 5 feet down tend to be in the 60's.

    There are inverter type fridges, I will assume you have switched to compact fluorescents and LED light bulbs are even more efficient, are you using a front load washing machine? Solar water heaters can help big time and if you're designing a home, you can likely integrate them into the design. Serious insulation in the home, SIPs,...
    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.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    I would agree that you need to look at conservation first... Modern heat pump A/C systems can be much more efficient than older systems, and in heat pump (for winter heat) mode, they are ~2-3x more energy efficient than resistance heaters (when you get below freezing, heat pump for heating become much less efficient).

    Also, if you use a fair amount of hot water (electrically heated), heat pump water heaters can save money too.

    Otherwise, if your utility supports Net Metering (and has consumer friendly pricing), a pure Grid Tied system (PV panels>GT inverter>AC mains) is much cheaper, more efficient, and reliable than an off grid power system (PV panels>charge controller>battery bank>AC inverter>AC loads).

    If you do not have a good net metering plan with your utility--You are sort of up the creek. An off grid solar power system is almost always going to be more expensive to buy/run than utility power.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    A kill-a-Watt meter ~$20 is a good start for plug in stuff and then you willl see where the large power use is at....
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    BB. wrote: »
    ... a pure Grid Tied system (PV panels>GT inverter>AC mains) is much cheaper, more efficient, and reliable than an off grid power system (PV panels>charge controller>battery bank>AC inverter>AC loads).

    I'll agree with all but the more reliable, at least in my experience, being very rural, I've had less down time with my off grid system and had better/cleaner electric.

    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.
  • Anawa
    Anawa Solar Expert Posts: 225 ✭✭✭
    GUSRENTIT, I've recently gone off-grid (March 2015) and utilize a 800Ah forklift battery bank in my configuration. I'm still learning about proper battery management, battery monitors, battery settings, etc.

    Your initial post was about using forklift batteries, but it seems as though it morphed into all that is involved in off-grid living. Apparently, you are in the decision making mode and understanding what you would be getting into is extremely important. I'm no expert, but you may have to alter your current energy consumption or be prepared to spend some major bucks.

    Is a self-installation something you are willing to do and do you have the where-with-all to do it? And then maintain it?

    I've been pleased with how my system is operating and producing energy so far, even though I've had some headaches. I can say without a doubt that Mini-split heat pumps and off-grid solar are compatible.

    Good Luck
    Paul
    Paul 
    in Georgia

    System 1: PV- 410w Evergreen, Mppt- Blue Sky Solar Boost, Batt - 225ah Deka AGM, 12v led house lighting,
    System 2: PV- 215w Kyocera, PWM - Morningstar PS30, Batt- 225ah Deka GC's, 12v led house lighting, Dankoff 12v water pump,
    System 3: PV- 1.5kw Kyocera, Grundfos 11 SQF well pump, 3000 gal above ground water storage, dom water & irrigation,
    System 4: PV- 6.1kw Kyocera, Mppt- Outback FM80-2ea, Inverter- Outback FX3648-2ea, Batt- 804ah GB traction, Grundfos BMQE booster pump 240v, Mitsibushi mini-splits 240v, 18k and 15k
  • Anawa
    Anawa Solar Expert Posts: 225 ✭✭✭
    GUSRENTIT, for the record, I have two living structures each having about 1,000 sf plus each. The floor plans are similar and very simple, one big space for living, cooking, dining, and sitting with two bedrooms each with baths. They are attached to a large covered "porch". In one unit, there is a 15,000 btu heat-pump and in the other there (primary residence) is a 18,000 btu heat-pump. These structures were recently constructed with very energy efficient.

    Paul
    Paul 
    in Georgia

    System 1: PV- 410w Evergreen, Mppt- Blue Sky Solar Boost, Batt - 225ah Deka AGM, 12v led house lighting,
    System 2: PV- 215w Kyocera, PWM - Morningstar PS30, Batt- 225ah Deka GC's, 12v led house lighting, Dankoff 12v water pump,
    System 3: PV- 1.5kw Kyocera, Grundfos 11 SQF well pump, 3000 gal above ground water storage, dom water & irrigation,
    System 4: PV- 6.1kw Kyocera, Mppt- Outback FM80-2ea, Inverter- Outback FX3648-2ea, Batt- 804ah GB traction, Grundfos BMQE booster pump 240v, Mitsibushi mini-splits 240v, 18k and 15k
  • oil pan 4
    oil pan 4 Solar Expert Posts: 767 ✭✭✭✭

    Take your average monthly power bill and add 3 zeros to that number.

    That should be the budget for an off grid system.

    Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.

    Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.

  • GUSRENTIT
    GUSRENTIT Registered Users Posts: 14
    I guess I skipped offering too much info. I currently live on 46 acres in Southern Colorado, and I'm on the grid 100%. Due to health problems I have to move to a much lower altitude, in like under 2000', and we have picked NW Arkansas. Once we sell all our places in Colorado, we will be buying in AR. We are planning on 40 to 80 +- acres, and somewhat remote, so we have been planning to go off grid, to run the whole operation, we are dog breeders and plan on also doing some Hydroponics. As for my skills, I have been a heavy equipment mechanic and a home contractor for most of my life, so I have hands on experience in many fields. I can build a house from the ground up, have full understanding of HVAC, plumbing, electrical, and so on.
    Where I'm at a loss is with what the "best" and most cost effective way to generate electricity, in the under 2000 KWHs a month. Regardless of how I intend to use that power. The conservation plan is geothermal heat pumps, with in well heat exchangers, well insulated buildings, energy efficient appliances, LEDs, and so on.
    So, we get back to producing electricity the most effective way,,, right now solar panels are under 20% efficient, wind is even worse and hit or miss at best, looked into hydro, and I like that the best, however it's not easy to find running water, where you need it, then after you create the electricity to have to store it. The weakest part of the equation, I see people with banks of 12v batteries that cost $550 each and only last 3-5yrs., so I started to look into the industrial side of things, large fork lift run 8 hrs on a charge, so why not use their batteries, well they are large, heavy and expensive, but since I'm building from scratch, it's not too much to overcome. So far this is what I found out, model # 24-85-33  48V has 1690 AHs in a 20hr cycle, with 64.9 KWHs and comes in at a whopping 5376 LBS and new retail is $8K, I figure with 2 of them I can run the whole place with several days of autonomy, and if I take care of them I can pull most likely 20 plus yrs of service from them, based on duty cycle. Solar panels, at about $1 a watt it's not cheap, but not horrible, 40 panels of 250watts each, will do the job. For a setup like that I thinking It will be $25K and last 25yrs, that works out to $1K a yr, or $83 a month, about half of what I'm paying now. Now you who are currently running off grid, and actually have to live with these systems, tell me all the things I'm missing or that I'm assuming wrong, that is what I need! Please be rough on me, it's the only way I learn. Thanks Gus             
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Some quick math using our "typical" off grid home recommendations (rules of thumbs that work out well for most people):
    • 2,000 kWH per month / 30 days = 66.7 kWH per day = 66,700 WH per day
    • 66,700 WH per day * 1/0.85 inverter eff * 2 days of storage energy * 1/0.50 maximum discharge (for longer batt life) * 1/48 volt battery bank = 6,539 AH @ 48 volt battery bank recommended
    I suggest a 5% to 13% rate of charge for Lead Acid batteries... And 10% or greater for an off grid home:
    • 6,539 AH * 59 volts charging * 1/0.77 panel+controller derating * 0.10 rate of charge = 50,106 Watt array nominal
    • 6,539 AH * 59 volts charging * 1/0.77 panel+controller derating * 0.13 rate of charge =65,137 Watt array "typical cost effective" maximum
    Say you have decent winter sun of 3 hours per day, the typical minimum solar array would be:
    • 66,700 WH per day * 1/0.52 typical off grid system efficiency * 1/3.0 hours of sun per day = 42,756 Watt array minimum
    So, those are the basic numbers--A much larger system than you would have estimated, I think.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • GUSRENTIT
    GUSRENTIT Registered Users Posts: 14
    Bill, a big THANK YOU, you seem to know your stuff! And YIKES, I guess my batt setup is about right, but my PV is way off. Can you explain to me the "rate of charge" of 10%? I guess I'm missing what you mean by that. Thanks
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Batteries are rated for capacity in Amp*Hours (at battery voltage). We use the C/20 discharge rate (stable current discharge for 20 hours will discharge the battery bank from 100% to 0% over 20 hours).

    A 100 AH battery:
    1. 100 AH / 20 hours = 5 amp steady discharge
    Note that if you discharge a battery faster, it will appear to have "less capacity"  (i.e., discharge over 5 hours it may appear to have 85 AH of capacity).

    So, we use that "20 hour rate" capacity number and multiply by 10% to find the recommended rate of charge:
    • 100 AH * 0.10 rate of charge = 10 amp recommended charge
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • GUSRENTIT
    GUSRENTIT Registered Users Posts: 14
    Thanks again Bill, got it now. Gus
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    By the way, your calculated battery capacity would give:
    • 1,690 AH * 48 volts * 0.85 AC inverter eff = 68,952 Watt*Hours = 69 kWH (from 100% to dead battery)
    For various reasons, this is not a good idea or way to run your system (taking the battery dead on a cloudy day).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • GUSRENTIT
    GUSRENTIT Registered Users Posts: 14
    Bill I agree, that is why I was planing on using 2 batts.
  • oil pan 4
    oil pan 4 Solar Expert Posts: 767 ✭✭✭✭
    edited September 2015 #19
    BB. said:

    50,106 Watt array nominal

    65,137 Watt array "typical cost effective" maximum

    42,756 Watt array minimum

    With solar panels costing between $1 and $3 per watt, by the time they get delivered to your door and $16,000 or 5 tons worth batteries not including shipping plus a bank of charge controllers, a whole pile of power inverters and backup generator. How is this going to save money?

    I am just curious.

    Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.

    Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.

  • GUSRENTIT
    GUSRENTIT Registered Users Posts: 14
    Good point, Sir! Maybe I'll get a real good diesel generator at auction. As most likely getting to the grid, where I'm looking to buy, will be a whole bunch of $$$$$ too. I will keep looking for options.
    Thanks for all the help and keep the advice coming. Gus 
  • zoneblue
    zoneblue Solar Expert Posts: 1,220 ✭✭✭✭
    You can certainly do it if you have the money, skills and patience. But NOONE here has ever come close to beating the grid on a price basis, unless:
    -therir intitial connect fee was really high
    -their grid rates are very high, think hawaii, NZ etc

    There was a post recently on midnite of a system this size. 44kWp PV, 17 midnite classics, 8 radian inverters, and a whole bunch of recycled tesla lithium batteries: See here: http://midnitesolar.com/Forum/index.php?topic=2675.0


     

    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    Your initial idea of forklift batteries is sound. They are often called traction batteries. They probably do easily give you the most battery for the money. They last a lot longer and can handle more abuse without dying.

    My current beef with solar is that it takes years to gain solar proficiency. Lots of time to make a lot of mistakes and grow a lot of grey hair. I asked for a good intermediate solar book recommendation. Crickets. Hundreds of beginner books that are almost useless after awhile.

    Might keep your eyes open for a commercial roof solar tear off...

    Life is easier on the grid...I started doing solar five years ago. New stress every month it seems.
    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
  • oil pan 4
    oil pan 4 Solar Expert Posts: 767 ✭✭✭✭

    I have worked with lots of traction batteries over the years. The one common thing I noticed with them is that they get abused a lot and still last years. Mostly from people just being lazy and not charging them.

    The only problem with using them off grid is they are one assembly and their weight usually starts at about 1 ton and just goes up from there.

    As long as you know you will be able to move the battery in and out of place then they are great.

    Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.

    Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.

  • GUSRENTIT
    GUSRENTIT Registered Users Posts: 14
    Yes I know about the weight, these are 5400 lbs each, Yep I have big backhoe.
  • lkruper
    lkruper Solar Expert Posts: 115 ✭✭
    GUSRENTIT said:
    Yes I know about the weight, these are 5400 lbs each, Yep I have big backhoe.


    what's the core charge?

  • GUSRENTIT
    GUSRENTIT Registered Users Posts: 14
    Best I can tell, they are brand new batts, with no core charge, they are about $8K each. From Midwest Lift Truck. GMB is around the same price, and they have refurbished ones that they give a 6 mo. warranty on, and are rated @ 85% of new, and are much cheaper. Now keep in mind that I have a large backhoe and trailer to pick up and deliver, and install. Also I have a way after finding out what I'm looking for, to find "deals". So far, my biggest problem is overcoming the generating factor, solar, wind, hydro, etc.. I found industrial diesel genset in the 20KW range cheap enough, and can derate it and run it on propane for a long time. So far my choice is Hydro, but damn it, it's hard to find the right land in the right place for the right price,,, I'm darn cheap too! On a bright note, I have time to shop, and I will be buying cash, which make people say yes to weird deals. The other things I'm trying to learn about is, inverters, charge controllers (are they basically voltage regulators?) , battery equalizing, I know about keeping them watered. Thanks People!  
  • oil pan 4
    oil pan 4 Solar Expert Posts: 767 ✭✭✭✭

    Ah, no point in paying the power company say $20,000 to put in a line AND still have to pay a power bill.

    If you are going to run a liquid cooled diesel generator try and do something creative with the waste heat like heat the house with it while it runs during winter.

    Some day I would like to have a 5 to 8 kw liquid cooled, 4 pole (1800rpm) single phase diesel generator in the garage and put a cast iron radiator inside the house and a standard automotive radiator out side the garage for summer use. I have been looking for one of those big heavy cast iron old school radiators at the scrap yard for over a year now with no luck.

    With charge controllers you have to decide do you want the cheaper old reliable PWM design or the much more efficient and much more expensive MPPT controllers.

    If that diesel generator does not have a turbocharger, put one on there. Going from diesel to turbodiesel can reduce fuel consumption by around 10%.

    Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.

    Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.

  • GUSRENTIT
    GUSRENTIT Registered Users Posts: 14
    I know, I'm a very old diesel mechanic, actually back in the day, went though Cummins engine school. I like the heat exchangers, as you can use them to heat water too. 
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    I think we should strive to keep things somewhat simple and straightforward.....for solar newbies. This guy has a dream for the future and we are already turbocharging the diesel genset and doing heat exchangers on the exhaust manifolds? Couple days ago we were telling him to forget about it?
    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
  • GUSRENTIT
    GUSRENTIT Registered Users Posts: 14
    It's all good, I like to hear all ideas and opinions. The more I hear the more ideas I get, and the more I learn. Thanks  
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    I don't know if that attitude will hold up once you realize everything that you are in for. Perhaps...   Solar is part witchcraft, part palm reading, part science, and all work.

    GUSRENTIT said:
    It's all good, I like to hear all ideas and opinions. The more I hear the more ideas I get, and the more I learn. Thanks  

    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