Need opinions on my 24v off grid design plz

GigrioS15
GigrioS15 Registered Users Posts: 7 ✭✭
First off Hello to all of you incredibly helpful and smart individuals, my name is Josh. Ive been reading here for some months now and my learning curve has been greatly shortened because you all took the time over and over to explain how it is. Thank you.

I have been living off grid for over a year now utilizing captured/filtered rain water w/shurflo rv pump 110v to pressurize the system on my mobile home. I live in Brooksville, FL and am currently using a 24v prosine 1800 sitting in the shed wired w 8ga undergroud to my panel in the house. Everything works great except that I have to trade out sets of batteries (2 sets so 4 bats total, 105ah 12v agms) with a set that is on a charger some 400 yards away every cpl days depending on consumption. Running power to my house is not an option and solar independence has been a dream for too long. Current power requirements are under 800w per day and Im waiting to bring over the freezer modded fridge that uses less than 400w per day. I know my loads will continue to grow and a small mini split is in my future eventually. Knowing all this I am wanting to size the system for the inevitable growing loads. I have a yamaha 2800 inverter genny, and a 6875 honda/coleman contractor syle. The current charger is a 12v batteryminder, so I will certainly need a new one for the forklift bat.

The proposed setup:

800-900ah 24v forklift bat, will utilize all four 105ah bats for 210ah @24v until I get the forklift bat.
housed in its own cobb hut w ventilation along w breaker boxes and charge controller and prosine 1800, then to the house 25ft away w 8 guage

10 265w SolarWorld panels http://www.solar-electric.com/solarworld-sunmodule-sw265-monocrystalline-solar-panel.html
mounted on 6x6 framework concreted into ground aprox 8 ft off ground, 60 ft run to cobb hut w charge controller

200v midnite classic and maybe another for backup in a faraday box

My questions are 1) Will this work as well and with room for loads as I hope?
2) I know I need to ground the array and the house is already grounded, anything else?
3) What breaker boxes and amperage breakers will I need and where?
4) What size cable should I use from the array to cc, cc to bat, and bat to prosine?
5) How should be monitoring this system?
6) What have I overlooked or missing out on?

Thanks in advance for any and all help!
Josh

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need opinions on my 24v off grid design plz

    Welcome to the forum Josh.

    Well let's see. You're using about 800 Watt hours per day now? And you plan to add another 400 Watt hour per day load? That would be 1200 Watt hours total. With conversion and inverter use probably 1400 Watt hours DC. On a 24 Volt system that's about 58 Amp hours used. That would be roughly 233 Amp hour battery bank @ 24 Volts.

    I don't see a need for 800 Amp hours of 24 Volt battery here. Why so big?

    The size of the battery bank will determine not only how much power you have to work with but also what is required to recharge it. So it's important to size that right to begin with.
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Need opinions on my 24v off grid design plz

    "and a small mini split is in my future"
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    Re: Need opinions on my 24v off grid design plz

    You are really getting close to 48v-land here. Especially if you expect to expand in the future.

    Might be better to take the leap now and configure everything for 48v. Sure you would need a new inverter, but you are likely going to need a larger one anyways with the mini-split.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need opinions on my 24v off grid design plz
    "and a small mini split is in my future"

    Ah. I keep missing things in posts. Ravages of age.

    An A/C is an unknown load because you can never know in advance how much it will run. That depends on the weather. So with 1200 Watt hours known and 4800 Watt hours available from 800 Amp hours @ 24 Volts you've got a 3600 Watt hour allocation for the A/C.

    800 Amp hour battery will max out an 80 Amp controller and require about 2500 Watts of array on 24 Volts.

    I agree with jcheil here; this is in 48 Volt territory. And that makes the difference for what wires/fuses/breakers you use.

    Check out the thread on mini-splits (it's very long but full of information) to get an idea what's involved with them: http://forum.solar-electric.com/showthread.php?5104-Sanyo-mini-split-AC-%28inverter-variable-speed%29
  • GigrioS15
    GigrioS15 Registered Users Posts: 7 ✭✭
    Re: Need opinions on my 24v off grid design plz

    Alrighty, I have already read up on mini splits and window units and would only be running one in aprox 500 sqft for a few hours per day, sunlight depending. I do not want to expand this system once complete and will be using it full time 12 months out of the year. I was ultimately wanting a 3kw - 3.3kw per day system with 1500kwh for led lights, router, inverter, led tv, shurflo 2088, blender and coffee maker(rarely used), etc. and the other 1500 - 1800 for a mini split during sunshine especially after the battery is at 100% SOC. Im pretty decided on going 24v route unless someone could show me how it would be cheaper to go 48v as I believe there are not as many 48v options out there and I didn't think it necessary. Also I already have the 24v prosine 1800, and we are very aware of what is using power and can balance loads as necessary, so not sure I need a bigger inverter either. I would like to not run the generator but it is an option for air conditioner duty. I was under the impression the proposed 2650w of paneling would be enough to take care of an 800ah battery and surely anything smaller, and the 800ah would be good for aprox 2.5 days if it were rainy/overcast where we are also unlikely to run the AC. Could someone show me the math please? Also, will the midnite classic 200 handle the numbers from the paneling? Thanks for any and all input and of course thanks for your time!!

    Josh
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    Re: Need opinions on my 24v off grid design plz

    Bill does a really nice job of detailing out what you are asking. However, the biggest variable is what you "think" your energy usage will be. I can tell you from experience, you are likely underestimating it. Everyone does. If possible, put a kill-a-watt meter on your current inverter that feeds your mobile home and let it run for a week or so. That would let you know exactly what you are using. The AC usage is a crap shoot, especially in Florida (I am also). But, it will be the majority off your consumption. And just wondering, washer/dryer in your future? Or, the worst power consumer(s), a spouse and/or kids? :):) Plan ahead :)

    But you are doing the RIGHT thing by planning first rather than buying first. 24v is not going to be any cheaper than 48v. However, it is more efficient and by going to 48v you have expandability when you do realize that you underestimated your usage. I personally was exactly where you are now a few months ago. I was on a 24v system, thought it would be enough, but knew I was right at the edge. I wished I had done 48v right from the start because now I had to sell all my 24v stuff at a loss. You are really not going to hurt anything going 48v now and you will likely thank us for pushing you that way in the future.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need opinions on my 24v off grid design plz

    Well yes a 2650 Watt array should supply 85 Amps @ 24 Volts and recharge an 800 Amp hour battery as well as maxing out a Classic 150 controller.

    A bit about system Voltages: http://forum.solar-electric.com/showthread.php?15989-Battery-System-Voltages-and-equivalent-power

    A couple things you mention: coffee maker. Check the Wattage on that as it could use all of your Prosine's capacity for itself, leaving you with no power for anything else; router may present the opposite problem in that it uses little power but is on a long time which adds up to a lot of Watt hours.

    In my opinion the A/C is the game changer between 24 and 48 Volt systems.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: Need opinions on my 24v off grid design plz

    Josh, Looks like you have though this out somewhat. I was you, sorta 4 years ago. I suspect you have done a well insulated Cobb hut since you knew you would want to live with off grid solar?

    I built a well insulated tiny cabin, and hoped to do much what your doing, how close? I used a Prosine 1800 watt inverter in a 24v system and used 4 golf cart batteries for a while. I had planned on staying in the small well insulated cabin and even purchased a 805 Ah Fork lift battery. Then things changes, the covenants for my cabin changed, and though grandfathered in, I was told they would rather I didn't live there. I found a great deal on a 'Tin Can' Mobile home, 16x60, changed from a 2000 watt array to a 4000watt array, but already had the 24v forklift battery, since this might well last 20yrs, I'm stuck in a 24v system. I would have preferred a 48v system in my situation.

    I have yet to buy a different inverter, I have 3 24v Prosine 1800watt inverters at this point. I had both systems up and running for nearly a year. though when I moved I purchased 4 golf cart batts and dropped the array back to @1600watts on a PWM CC.

    I'm single and have gotten use to the limits of an 1800watt inverter. I converted my water heater from 3600watt 240v to 900 watt 120v, it takes a while but I have hot water most days, I have several things that don't run together, the water heater, toaster, toaster oven(which I don't run with much of anything else at 1400watts),clothes washer, grain grinder, microwave, window air... I suspect you can run a solar water heater year round with no issues in Brooksville.(I use to live in Tallahassee for many years) I had intended to buy a 120/240 inverter but several things changed and I am currently content with the 1800 watt inverters.

    I think if I was in your situation I would plan to use the current batts until dead, you can likely do some modest air conditioning, though NOT 500 sq ft, I was doing a 10x16 well insulated cabin for a few hours a day.

    With a 2000 watt array and a Midnite classic, you can likely run once the batteries are topped off, and a couple hours at night. Several ways to implement this, you will want the to use the shunt based battery monitor to monitor the actual charging of the batteries and depending on you presence or lack there of, put the AC on a timer to kick on at noon or so, you can monitor the classics and see when they are switching into absorb mode, and either have the charge controller switch on the A/C or put them on a timer to come on at roughly that time. You will be a little tight running a freezer conversion, but I ran a window unit and a small fridge for a couple summers, though I admit to having shut down the fried a few times to gain an extra hour+ or A/C run time.

    I guess in 15 yrs or so, if I'm still around I'll look at switching to a 48 volt system, perhaps I'll still have the Prosines up and running... I had 2 mounted in the power center, but had a fan go out on one of them, I had intended to run one on an A/c by it's self, but now a work during the day. I might put 2 in it again, but 1 would just be in reserve incase of a failure.

    I suspect you are close to max on the standard 150 classic, and perhaps over on a Classic 200. Do you need the higher voltage capable of the classic 200? I run into a battery bank and power center under my array, and nearly 100 feet to my 'Tin Can' breaker box. since I just have 1800 watts I'm just using 10 gauge wire. MIdnite has a Sizing Tool Here and they have an Active Forum Here.
    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.
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,730 ✭✭✭✭✭✭
    Re: Need opinions on my 24v off grid design plz
    GigrioS15 wrote: »
    Alrighty, I have already read up on mini splits and window units and would only be running one in aprox 500 sqft for a few hours per day, sunlight depending. I do not want to expand this system once complete and will be using it full time 12 months out of the year. I was ultimately wanting a 3kw - 3.3kw per day system with 1500kwh for led lights, router, inverter, led tv, shurflo 2088, blender and coffee maker(rarely used), etc. and the other 1500 - 1800 for a mini split during sunshine especially after the battery is at 100% SOC. Im pretty decided on going 24v route unless someone could show me how it would be cheaper to go 48v as I believe there are not as many 48v options out there and I didn't think it necessary. Also I already have the 24v prosine 1800, and we are very aware of what is using power and can balance loads as necessary, so not sure I need a bigger inverter either. I would like to not run the generator but it is an option for air conditioner duty. I was under the impression the proposed 2650w of paneling would be enough to take care of an 800ah battery and surely anything smaller, and the 800ah would be good for aprox 2.5 days if it were rainy/overcast where we are also unlikely to run the AC. Could someone show me the math please? Also, will the midnite classic 200 handle the numbers from the paneling? Thanks for any and all input and of course thanks for your time!!

    Josh

    Just be sure and use an inverter based mini-split and you will be fine with 24VDC. About 10 of my customers are doing this along with me also. I wrote and started the mini split thread here when I took a chance that the split concept could work offgrid. Rolled the dice on that one!

    No window units or you will need 48vdc !

    Remember you are going to have to address how you will get solar power late in the day or you will be deeply cycling any battery ! Follow the sun!
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • zoneblue
    zoneblue Solar Expert Posts: 1,220 ✭✭✭✭
    Re: Need opinions on my 24v off grid design plz

    If its 12/24v appliances youre worried about, 48V DC DC converters are now more readily available, so that neednt necessarily be a factor.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: Need opinions on my 24v off grid design plz
    No window units or you will need 48vdc !

    While I respect Dave, I have run a window unit for some 5+ years now on 1400 and 1800 watt inverters with out a problem, for 4 years on a 24v 4 golf cart battery system, and a couple on a forklift/traction battery also 24v. While I recommend moving to a 48v system, it can certainly be done on a 24v.
    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.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need opinions on my 24v off grid design plz

    Some people tend to forget that not everyone lives in sunny California and have tracking arrays.

    If you need the higher storage capacity available with 48 Volt systems you go with a 48 Volt system. Managing that will be easier than living on the edge of a 24 Volt system's abilities.

    Keep in mind most of the time I recommend 24 Volt systems.
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,730 ✭✭✭✭✭✭
    Re: Need opinions on my 24v off grid design plz
    Some people tend to forget that not everyone lives in sunny California and have tracking arrays.

    If you need the higher storage capacity available with 48 Volt systems you go with a 48 Volt system. Managing that will be easier than living on the edge of a 24 Volt system's abilities.

    Keep in mind most of the time I recommend 24 Volt systems.

    So, why not now?

    I do live in California but have clients all over the world using this strategy. Most are using 4KW inverters and 1,100 amp hour storage and are certainly not on the edge as you say. The beauty of the mini split is that someone like the OP can start small and move up over time. Florida is a challenge and having arrays that can power the mini-split for the solar day is the strategy. It does not matter if the array tracks or is 2 fixed arrays for this strategy.
    He could even do this manually if that appealed to him while he starts small. Yuk on that one!
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need opinions on my 24v off grid design plz

    Because it is better to store and use power as Voltage rather than as current.

    1,100 Amp hours @ 24 Volts requires two charge controllers.
    550 Amp hours @ 48 Volts requires one. Same amount of power.
    Savings: $600 right there.
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,730 ✭✭✭✭✭✭
    Re: Need opinions on my 24v off grid design plz
    Because it is better to store and use power as Voltage rather than as current.

    1,100 Amp hours @ 24 Volts requires two charge controllers.
    550 Amp hours @ 48 Volts requires one. Same amount of power.
    Savings: $600 right there.

    The kind of money we are talking about is not that much at system level, and you get redundancy, and you will need two controllers if you have 2 arrays facing differently!

    The OP is in Florida and even with the very small load of a mini-split will be running at night. He will need to save his battery for when the sun is down. He will need to power his cooling from solar well past 6 pm. With the afternoon thunderstorm and clouds he will need a generator. I sure do not miss my time there without a mini-split!
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need opinions on my 24v off grid design plz
    The kind of money we are talking about is not that much at system level, and you get redundancy, and you will need two controllers if you have 2 arrays facing differently!

    The OP is in Florida and even with the very small load of a mini-split will be running at night. He will need to save his battery for when the sun is down. He will need to power his cooling from solar well past 6 pm. With the afternoon thunderstorm and clouds he will need a generator. I sure do not miss my time there without a mini-split!

    If $600 isn't much, send it to me.

    I think he may find he needs even more capacity for exactly the reasons you mention. As such 48 Volts would accommodate up to 800 Amp hours on one controller. That's about 9 kW hours at 25% DOD.
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    Re: Need opinions on my 24v off grid design plz

    I just made that same mistake a year ago when I went from 12v to 24v instead of 48v.
    A month ago I just went to 48v and will end up having a loss selling my 24v equipment.
    In my opinion, which is not very valuable because I am not one of the experts, if you are going to be running AC, just go with 48v to start with and save the money as coot said. I cannot be happier with the efficiency gained JUST by going to 48v without expanding the size of my system.
    I have 2 parallel strings of batteries instead of 4, less current/heat in the same sets of wires, way more efficient inverter.
    Redundancy is nice, yes, but at what cost? That varies by the customer/bank.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,730 ✭✭✭✭✭✭
    Re: Need opinions on my 24v off grid design plz
    jcheil wrote: »
    I just made that same mistake a year ago when I went from 12v to 24v instead of 48v.
    A month ago I just went to 48v and will end up having a loss selling my 24v equipment.
    In my opinion, which is not very valuable because I am not one of the experts, if you are going to be running AC, just go with 48v to start with and save the money as coot said. I cannot be happier with the efficiency gained JUST by going to 48v without expanding the size of my system.
    I have 2 parallel strings of batteries instead of 4, less current/heat in the same sets of wires, way more efficient inverter.
    Redundancy is nice, yes, but at what cost? That varies by the customer/bank.

    You asked about what is currently out there for mini-splits. The LG and several others have SEER cooling over 25 and a few at 28. Even Home Depot has a one ton unit with 25 SEER. When shopping there are different models within a family and some of the people who sell the units will substitute other models. Verify that you are getting what you want. The best in 1 ton and 3/4 ton units are around 1.4K plus $200 for a line set. In the old thread alot of the models have changed but the basics are there and you should read it again. Make sure your model can be installed by you (if you choose) and how the 5 year warranty will be verified!

    I believe that you could have noticed efficiency increase but that is mainly because of the battery strings you had or loss to your array. In a well designed/installed 24V or 48V offgrid solar system, there should be very little difference in efficiency. Other than a cost difference in charge controllers which may be overcome by other requirements, they are similar efficiency in the power ranges being discussed here.

    The OP also said that he might run 24V appliances and without the conversion loss on 48 volts he could save energy here. He also may use the Square D circuit breakers and load centers at Home Depot that are listed below 50vdc. Less batteries to hook-up will save on cables and connectors. A DC freezer also could allow the the inverter system to be shut down for unattended operation (merchant marine 3 month shifts) I have a few of those...
    They always bring me Fish......
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • GigrioS15
    GigrioS15 Registered Users Posts: 7 ✭✭
    Re: Need opinions on my 24v off grid design plz

    Ok, been doing some heavy thinking and I've decided to go 48v, I'm sure I'll thank everyone for pushing me that direction. So since I'll need a new inverter lets start there first. I already have an exeltech 600 48v unit and I'm considering the vfx3648 outback, or for a little more the us made magnum MS4448PAE?

    I certainly don't need all 4400w but 220v and the charger is very attractive.

    If I go with the outback should I use their cc as well or stick with the usa made midnite products I've been dreaming of?

    I also found a sanyo inverter split for $500, only used for 2 months and the guy went bigger. 11,900btu @ 115v of goodness, just picked her up today. Also would like to thank Photowhit for turning me onto Sun Electronics down in miami. They have some chaorisolar panels 280w poly for 59 cent/watt, or $165 otd if you buy 21 or more. Here are the specs

    http://sunelec.com/datasheet-library/download/ChaoriSolar_crm156P-60.pdf

    I know they are made in china so I'm not super excited about that, but the other option is around $1.18/watt shipped to my door, exactly double! I can drive to miami to see some friends and pick these up tax free. What does everyone think about going with these panels? I would put 10 up for 2800w of array, and store the other 11 and an extra charge controller in a special place.

    Next is the battery, really ultimately wanting a forklift battery so 450-500ah 48v should be about right, right?

    Need to check with local dealers and see whats available. Until then I will arrange my four 102ah C&D Technology agm ups batteries in a string and see how long they last. How are we doing so far? Im pretty excited...
  • ButchDeal
    ButchDeal Solar Expert Posts: 35
    Re: Need opinions on my 24v off grid design plz
    GigrioS15 wrote: »
    Ok, been doing some heavy thinking and I've decided to go 48v, I'm sure I'll thank everyone for pushing me that direction. So since I'll need a new inverter lets start there first. I already have an exeltech 600 48v unit and I'm considering the vfx3648 outback, or for a little more the us made magnum MS4448PAE?

    If you are thinking of going with the vfx3648, you might consider the outback Flexpower One. It is an integrated solution that includes the inverter, FlexMax 80, and Mate3. You are going to want the Mate3 so you can control the inverter anyway. The Flexpower One has most of the wiring all done with both AC and DC breakers and boxes.

    http://www.outbackpower.com/outback-products/integrated-systems/item/flexpower-one
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: Need opinions on my 24v off grid design plz

    I PM'ed you about Sunelec since your located so close, be aware that it appears that China may allow "Chaori Solar" to fail. That said their panels appear to be well made and once installed it's rare for Panels to fail (Bill is at least one exception to this). I believe Sunelec may be willing to agree to warranty them, but get it in writing. They have treated me well, even replacing a panel purchased FOB Miami which they arranged delivery to Mid Missouri and was broken in shipping. They are much more of a wholesale operation, don't expect helpful advice, though they at least don't call 'grid tie' type panels 24V...lol.

    Northern Arizona Wind and Sun is very kind in allowing this space for a forum of the best moderators and contributors, may who are experts in the field, including sightings of engineers from Midnite, and others. While they are kind enough to allow discussion of others, let it be known that they are very knowledgeable, and can help with problems, past weather your panels have been delivered. You get what you pay for, you may well want the more knowledgeable staff when assembling your system...

    Forklift batteries have a learning curve as well, I'm around 4 years into mine(?) and they require a bit more attention so far, though I hope to get to a point where my system does most of the maintaining aside from regular watering and evaluation.
    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.
  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Need opinions on my 24v off grid design plz
    ButchDeal wrote: »
    If you are thinking of going with the vfx3648, you might consider the outback Flexpower One. It is an integrated solution that includes the inverter, FlexMax 80, and Mate3. You are going to want the Mate3 so you can control the inverter anyway. The Flexpower One has most of the wiring all done with both AC and DC breakers and boxes.

    Most of the installers around here prefer Midnite's stretch ePanel-for-Outback to the Outback flexpower one. The stretch epanel is easier to work in, and more customizable than the Outback system. They are available as a kit or as prewired.

    Regarding 24 vs 48 volts... a lot depends on your choice of battery. If you can get the capacity you want in a single string at 24 volts, the advantages of 24 volts look a bit better. If you were planning to use two strings of battery at 24 volts, then I would suggest taking those same batteries and putting them in a single string at 48 volts.

    Regarding forklift battery.... you're in a warm location. A forklift battery has all of its cells squeezed together in a metal box... not the best arrangement for keeping the batteries cool. Individual 2 volt cells can be spaced with an inch of air between them.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • GigrioS15
    GigrioS15 Registered Users Posts: 7 ✭✭
    Re: Need opinions on my 24v off grid design plz

    Well I'm finally at the point where I'm ready to start purchasing the gear. As was suggested. I looked into the stretch epanel with a magnum 4448 prewired with the midnight cc. I think its the wisest and most obvious choice to make. So the only question I really have left is how many of the chariosolar panels can I run and in which configuration? I want the most possible while remembering I will only have a single string of 4 102ah for the time being.

    Here are the specs:
    Pmax 280W
    Voc 44.9V
    Isc 8.28A
    Vmp 36.0V
    Imp 7.77A
    http://sunelec.com/datasheet-library/download/ChaoriSolar_crm156P-60.pdf

    As always, thanks so much for the help!
  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Need opinions on my 24v off grid design plz
    GigrioS15 wrote: »
    So the only question I really have left is how many of the chariosolar panels can I run and in which configuration? I want the most possible while remembering I will only have a single string of 4 102ah for the time being.

    Here are the specs:
    Pmax 280W
    Voc 44.9V
    Isc 8.28A
    Vmp 36.0V
    Imp 7.77A

    There's not much in the way of limits... many folks "overpanel" their systems. When it's sunny they can't use all the potential power, when its overcast they can actually get some usable power.

    There are limits to how much current the batteries can handle... are your batteries flooded or AGM? it makes a difference, AGMs can handle higher charge rates.

    Next consideration is the panel configuration... Three in series (3 x 44.9 volts) will be too near the Vmax limit of a 150 volt controller. Two in series (2 x 36 volts) is cutting it close for a 48 volt system, especially if you have any voltage drop on your 60 ft run between array and controller. Heavy cable can minimize the voltage drop.

    My advice is 2 panels in series. 1 string of 2 panels will need 10 awg cable, 2 strings of 2 panels per string will need 8 awg cable.

    If you want 3 panels in series I would suggest the Midnite Classic 200 volt controller.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: Need opinions on my 24v off grid design plz

    If you have in mind your final system, I would buy the panels for it now, you can set the Midnite Classic to Output only up to what the battery bank(now and latter) can handle 13-15% of capacity at a 20hr rate with flooded, as much as 25% for some sealed and as little as 5% on some sealed!
    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.