Need help with controller and 100v open panels

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  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
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    Re: Need help with controller and 100v open panels

    I PM'd you about the cables.

    I think you must have been here a while to use the personal message system, if you can't get my PM I'll ask a Moderator to send it to you. just respond 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.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
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    Re: Need help with controller and 100v open panels

    Pm should work for everyone. Feel free to pm me your details and I will email to the email on file

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
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    Re: Need help with controller and 100v open panels

    Sorry I thought you had to post 5x and be here for 2 weeks or something, must be another site. Thanks! Message has been sent. Mods hard at work again!
    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.
  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
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    Re: Need help with controller and 100v open panels

    What type of pole system do you use? did you need cables and how high did you place yours?

    How many batteries do you have in your bank?

    I used a schedule 40 3" dia GI pipe and just welded another pipe on top that fit the clamp of the Air X. The pipe is connectetd to my water tank tower achieving a height of about 40'.

    For cables I used 3 wire #6 royal cord.

    Basically my system is a 48 volt system with 4 - 60 watt sharp solar panels in series connected to 4 - 100Ah 12 volt batteries connected in series.
  • firefly101
    firefly101 Registered Users Posts: 20
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    Re: Need help with controller and 100v open panels

    Thanks for the replies. Sorry I was out and not able to reply for the rest of the day.

    I would like to know Why some use 6v systems? since you have to do parallel anyway to increase the what whats the advantage of the 6v over the 12v system? Seems like 12v would be easier to work with?




    Photowhit, On the palet price, that was my problem, I seen real good deals if you get a full pallet but I just didnt have that much available for a backup system yet. I planned on piecemealing it 1 panel at a time, but the price was low enough and I couldnt find anywhere a good price per wattage, and as you know its hard when you are new and trying to stay within price. lol

    The controller is a hit, but on th bright side it will last longer and be more effecient than regular controllers.


    I PM'd you thanks


    Bill,

    I plan on placing these panels on the roof, and now that you said Flares shouldn't Zap the off systems that would be a good place to store. This would allow the batteries to be maintained by the controller extending the batteries when I need them. Boy thats good to hear about the flares because if it did happen we all would be effected badly from it. Look at Japan now with its disaster.

    Tony,

    Thanks, that info helps.
  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
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    Re: Need help with controller and 100v open panels
    firefly101 wrote: »
    I would like to know Why some use 6v systems? since you have to do parallel anyway to increase the what whats the advantage of the 6v over the 12v system? Seems like 12v would be easier to work with?

    Are you speaking of batteries? I'd read the Battery FAQ's I think someone has already created a link for you.

    All lead acid batteries are basicly a bank of 2 volt cells, a 12 volt car battery is a bank of 6 - 2 volt cells. Golf carts run on 36 or 48 volts, but a battery with enough amp hours would weight in the hundreds of pounds, so the batteries are made of 3 or 4 cells for 6 or 8 volt batteries weighing in at 50-60 lbs and wired together to make a battery bank.

    Really large batteries are made from banks of individual 2 volt cells, that can weigh 100+ lbs each, a fork lift/traction battery is made this way. Special batteries for solar home like the HUP One are very similar, Heres a link showing a single cell lifted half out of a steel case.
    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: 33,439 admin
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    Re: Need help with controller and 100v open panels

    FF,

    Here is a good thread with lots of Solar Flare discussions:

    Making a PV system survivable in EMP/CME conditions?

    Regarding battery bank configurations...

    In general, I don't like to parallel a bunch of batteries together into a single bank... Several issues:
    1. Two 12 volt batteries in parallel, 12 cells to check water level vs two larger AH 6 volt batteries in series (6 cells to check)... More parallel banks, multiplies the numbers of cells to check.
    2. I suggest avoid paralleling batteries as they don't always share charging/discharging current well. Have to be careful with wiring and monitor once in a while with a DC Current Clamp Meter. I recommend trying to not exceed 3 parallel strings.
    3. A single string is very easy to monitor cells. If you have a bad cell (open or sorted), it is very easy to find with a volt meter. With many parallel strings, a bad cell can be difficult to notice--and can even cause other cells/batteries to fail if not caught in time.
    4. Each parallel battery string should have its own dedicated fuse or circuit breaker--This adds cost/complexity to the system.
    That is not to say that there are many people with more than 3 parallel strings, properly wired and monitored, that are perfectly happy with those setups.

    Sometimes, there are practical limitations that force parallel strings...

    One is battery weight. There are some massive single cell and 2/4/6/etc. batteries that need a crane or forklift to move around. Many people simply do not have the concrete floor / crane / lift to move the huge cell batteries around. And they have to construct their battery bank from multiple parallel smaller batteries/cells.

    From an energy point of view, two 12 volt 100 lb batteries in parallel has the same amount of energy as two 100 lb 6 volt batteries in series.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • firefly101
    firefly101 Registered Users Posts: 20
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    Re: Need help with controller and 100v open panels

    Interesting. What about costs do you think the costs would be about the same for 6V batteries? and would a NAPA carry a 100lb 6v Battery?

    So really there is no real benefit to 6v except when you get the large batteries which in some cases you think you could get a 100lb 12v and get 2 of those?

    I was just curious if my cost effective 12v Batteries which would cost $70-$90 would be more cost effective than these larger batteries if they are not available locally.

    Photowhit, I did look at the Battery FAQ but it didnt cover the exact question of why I would want the 6v over 12v in way that was satisfactory.

    I just dont see the benefit unless you get the huge $350 6v batteries, then you are getting power for your series.

    But whether I use 2 12v or 2 6v I still have 2 Wires to connect to the battery, unless the Parallel is the problem and the series isnt?

    I think I will call Napa today and find out if they have BIG 6V Deep cell batteries if Series is better that would atleast only provide 2 in parallel if I take 2 6v combined and connect in parallel another 2 6v that would only be 1 parallel connection.

    Would that setup be better? Also what type of breaker or fuse do you suggest between batteries I would like something small and self contained like a small 30amp fuse or something.

    I was reading on the FAQ and I noticed that the Solar panels need to be grounded also. so should I just drill a small screw with a thick wire leading to a grounding rod for all 4 panels?

    BTW thanks for that thread link it was interesting, but the question still remains no one knows for sure. lol But it is nice to hear the theories on solar flares and EMP. As long as home can produce off the grid power civilization can still continue some.
  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
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    Re: Need help with controller and 100v open panels

    On the subject of batteries. Would forklift or golf cart batteries be on the same level as deep cycle batteries for RE? This would be in terms of Ah capacity and cycle longevity.

    The reason I ask is that forklift batteries are available here but deep cycle for RE are hard to come by.
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
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    Re: Need help with controller and 100v open panels
    tonygcan wrote: »
    On the subject of batteries. Would forklift or golf cart batteries be on the same level as deep cycle batteries for RE? This would be in terms of Ah capacity and cycle longevity.

    Hell yes. Internally, forklift cells are pretty much identical to stationary battery cells with some minor difference:
    - Sometimes they have a higher density electrolyte which gives more capacity at the expense of cycle life.

    and the important mechanical differences:

    - The cells themselves don't seem to have very strong walls, because they're expected to be packed together in a metal container. This means less ventilation between cells so they're likely to get hotter.
    - Less space for electrolyte above the plates because of height restrictions, so you may need to water more frequently.
    - Might need more frequent EQ charges
    - Higher self-discharge rate, some say 1% per day.

    The biggest difference is in the price, I expect that this is because of market forces - the market for forklift batts is just so much bigger than RE, that economies of scale means a cheaper product.

    As for cycle life, bear in mind that forklift batts are designed for industrial applications where they're charged overnight, then discharged to 80% DoD, every day for 5-6 days a week. Under these conditions they're expected to last about 5-7 years. Sticking them in a gentle RE system where they're not moved, kept cool and don't discharge below 50% is luxury for them ;) I would expect very similar life expectancy as stationary batteries.
    If you want to compare cycle life, most batts are here carry a rating based on EN 60 254-1 or IEC 60 254 standards. Typical values:

    20 % DOD 6,000 cycles
    40 % DOD 3,000 cycles
    60 % DOD 2,000 cycles
    80 % DOD 1,500 cycles
  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
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    Re: Need help with controller and 100v open panels

    That's encouraging! I'll check out range of batteries available for forklift batteries next week. Do I look for the same specs, i.e. Ah rating at C/20?
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
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    Re: Need help with controller and 100v open panels

    You can try looking for C20, but I think most rate them as C5. For a rough conversion:
    C20 = C5 * 1.24

    You might also be able to specify the number of plates. In Europe the battery models are usually named: [number of plates] PzS [capacity at C5]

    So the same manufacturer might have 5 PzS 400 and 7 PzS 400, both have the same capacity, but the second one has more plates for more instantaneous Amps - but it will likely age faster because the plates are thinner.

    When I was shopping for mine, I checked what the similar sized stationary batts were rated as, and in the stationary world there was only 1 option for the number of plates which increased linearly with capacity, e.g.: 5 OPzS 500, 6 OPzS 600, etc.

    So I ordered the forklift batts following the same progression.
  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
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    Re: Need help with controller and 100v open panels
    firefly101 wrote: »
    Interesting. What about costs do you think the costs would be about the same for 6V batteries? and would a NAPA carry a 100lb 6v Battery?

    Someone just priced Costco 6v deep cycle batteries for $73 each + $9 core charge. I think Costco was where you were going for the 12 v battery?

    So really there is no real benefit to 6v except when you get the large batteries which in some cases you think you could get a 100lb 12v and get 2 of those?

    I was just curious if my cost effective 12v Batteries which would cost $70-$90 would be more cost effective than these larger batteries if they are not available locally.

    Photowhit, I did look at the Battery FAQ but it didnt cover the exact question of why I would want the 6v over 12v in way that was satisfactory.I just dont see the benefit unless you get the huge $350 6v batteries, then you are getting power for your series.

    # 1 Math - 2 - 6V 220 Amp Hour batteries = 1 - 12 volt battery bank of 220 Amp Hours

    Cost 2 x $73 + 1 - $5 connecting wire ( wired directly into a fused breaker/disconect in front of inverter and charge controler) = $151

    #2 - 2 - 12V 110 Amp Hour batteries = 1 - 12 volt battery bank of 220 Amp

    Cost 2 X (place price here) + 2 - $5 connecting wires + 2 terminal fuse blocks $16.75 each + 2 terminal fuses $11 each wired into a fused breaker/disconect in front of inverter and charge controler.


    But whether I use 2 12v or 2 6v I still have 2 Wires to connect to the battery Bank, unless the Parallel is the problem and the series isnt?

    yes


    On top of these values, did you note while reading the battery FAQ's that larger cell battery banks last longer? also the note on added maintanance with extra strings and cells. Extra benifits to a single string!

    I think I will call Napa today and find out if they have BIG 6V Deep cell batteries if Series is better that would atleast only provide 2 in parallel if I take 2 6v combined and connect in parallel another 2 6v that would only be 1 parallel connection.

    If your looking for more capacity, you'll likely need more panels, 400 watts will work out OK for 220 amp - 12 V bank, but with a larger bank you may face continued under charging, though if you don't plan on any loads and just using as a backup might support a tiny bit larger, good question for another thread.

    Would that setup be better? Also what type of breaker or fuse do you suggest between batteries I would like something small and self contained like a small 30amp fuse or something.

    I was reading on the FAQ and I noticed that the Solar panels need to be grounded also. so should I just drill a small screw with a thick wire leading to a grounding rod for all 4 panels?

    All 4 panels, Charge controller, inverter all to the same ground, also a new thread might be in order.

    BTW thanks for that thread link it was interesting, but the question still remains no one knows for sure. lol But it is nice to hear the theories on solar flares and EMP. As long as home can produce off the grid power civilization can still continue some.

    18 characters 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.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
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    Re: Need help with controller and 100v open panels

    Solar RE batteries tend to be 3-15 hour life... With typical Golf Cart batteries down downs towards the 3-8 year end.

    Good quality "Fork Lift" (traction) batteries can be in the upwards of 20 year life.

    Downside for Fork Lift batteries... They tend to use more distilled water for keeping electrolyte levels. And they tend to higher self discharge (requires a bit larger solar array to keep up).

    When setting up your system, you might try to find used forklift batteries.

    One user here was very happy setting up a fabrication shop in Hawaii doing this. He was able to use 32/36 volt batteries and wire around "bad cells" to make 24 volt banks from them.

    Look for threads started by user "adas".

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • firefly101
    firefly101 Registered Users Posts: 20
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    Re: Need help with controller and 100v open panels

    Photowhit,

    Napa doesnt carry the 6v so I guess Costco is the key. I did miss the part about the batteries lasting longer with larger cells. Thats good to know.

    So that explains why Electric system batteries are 6v or less, you get more and series connection is no safety issue.

    Well it only makes sense to listen to those that know, Already you guys are saving me headaches and money in the long run. First the Inverter choice, then Battery type, cabling, and now voltage.

    Dont forget I plan on seriously getting a 500-1000w Wind turbine also so for now I think 2 6v Batteries are all I need and then when I get the turbine I can get another 2 batteries.

    One nice thing about the higher voltage is I should be able to use simple 110v breakers from HomeDepot, for the panels. I really appreciate all the help, epecially when the costs are so much and information is not always available in a simple format to the layman.

    Forklift Batteries are really expensive arent they? Seems the best cost is the 6v deep cell #27 or higher size batteries.
  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
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    Re: Need help with controller and 100v open panels
    firefly101 wrote: »
    Dont forget I plan on seriously getting a 500-1000w Wind turbine also so for now I think 2 6v Batteries are all I need and then when I get the turbine I can get another 2 batteries.


    Well there might be other issues, batteries like to age together. I don't do wind, I understand they require a charge controller that can do a diversion load, perhaps I've said that before. We have some wind people here, some would say I'm pretty 'windy'... lol
    firefly101 wrote: »
    One nice thing about the higher voltage is I should be able to use simple 110v breakers from HomeDepot, for the panels.

    I think only one brand is rated for DC, most only have AC ratings, I didn't think about using them for panel breakers, but I guess you could, I think they are often used for DC disconnect boxes, There is a thread somewhere, but likely someone will jump in and give you the brand to look for...

    firefly101 wrote: »
    Forklift Batteries are really expensive arent they? Seems the best cost is the 6v deep cell #27 or higher size batteries.

    Depends on how you figure costs, I originally set up for a planed 24 volt 440 amp battery bank of 8 golf cart batteries, which I would expect a life of 4 years (they would get minimal use most of the years and abused for 6-12 weeks during the summer running an AC) After most of 10 years off grid now, I'm confident enough to go with a forklift battery, expecting 20 years service with the possibility of more. 700 Amp hour forklift battery will cost @ $2500 delievered, and will have added capacity.

    8 Golf Cart x 5sets = 40 x $73 = $2920

    We'll see if this works out, I'll post back in 20 years.... I hope!

    As to your battery situation, It's a hard nut, I designed my system for 8 or 12 Golf cart batteries but I already had 4 golf cart bateries that were a little over a year old, so for the past 4 years, I've been waiting for my batteries to die. I didn't want to mix old with new, and I've been toying with the idea of going with a forklift battery for a while.

    The final push is when I discovered that the batteries do qualify as part of my solar electric system and are eligable for the 30% tax credit, which migh not always be around, so it made sense to me to go ahead and do it this year.

    As to if batteries qualify, the IRS won't come out and tell you yes, so do your own "due diligence". To me it makes no sense are batteries are not a 'green' element, indeed "off grid" typically uses more energy in the construction of the elements than it produces over it's life life time. But I'm poor and want to take every advantage I can.
    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: 33,439 admin
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    Re: Need help with controller and 100v open panels

    What size and type battery bank are you going for? Volts, AH, AGM/sealed, etc.

    1,000 watts of wind power needs more that a minimum sized battery bank to absorb all that current.

    Also, make sure you have a good match between bank voltage and turbine/controller requirements. Many smaller turbines have good low wind performance but poor performance at 24-48 volts.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • firefly101
    firefly101 Registered Users Posts: 20
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    Re: Need help with controller and 100v open panels

    Hello and thanks for the info.

    On the Batteries I am using a 12v system and you guys convienced me to use 6v Deep Cell batteries or 6v period because of the series.

    The forklift batteries are out of the question. Way over my price range for my use, but I agree Photowhit that sounds like a good option, also something else with the inflation that keeps going on year after year, you will save even MORE money as the same golfcart batteries will probably cost double 5-10 years from now.

    On the wind Turbine, I noticed the MAX ratings need a Fast wind and that only happens in really windy days, I figure a 1000w model would give 3-500w average which if I increase the battery bank to 440-660amps should be ok if what you guys tell me is right?

    The wind is down the road anyway, I still need to get my solar up. I figure I will have a nice Dump load and may do a 2 Bank system so the Wind turbine will charge 2 banks instead of one large one? But 1000w is unlikely as the wind would have to be pretty bad. By reading some of the reviews and stuff I see most get about one quarter to one half the rating on average.

    Am I wrong on that? I dont plan on getting the most expensive 1000w model anyway, so I Figure they pad the rating so the buyer thinks they are getting more. I might just get the BIG 6v Batteries from NAWind&Sun when I do the turbine so I GET the Large amp batteries for the wind system.


    If anyone finds the Brand I need for DC breakers let me know. Also should I use 4awg or 2awg for the battery series wires? and on the 100v side what regular wire gauge that is safe can I use? I want to keep it safe but also not waste money that could go elsewhere.

    Photowhite to be off grind how many watts and amps do you use and what about Washing machines or Dryers? are 12v mdoels more effecient than the 110v?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
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    Re: Need help with controller and 100v open panels

    The problem with a "small" battery bank is when you get that 1,000 watt surge (around 70 amps at 12 volts), you can actually overcome the battery's ability to absorb current and drive the bank voltage to >> 14.5 volts and wipe out your connected DC loads/devices.

    Roughly, for flooded cell batteries, you should use C/2.5 as your maximum surge current. For an 80 amp wind turbine:
    • 80 amps * 2.5 = 200 AH minimum battery bank.
    Also, asking about gauges of interconnect wiring, we need to know your surge power you plan on supporting... Especially with 12 volts, you have only about 1.0 volt headroom maximum for voltage drop in your interconnect wiring (11.5 volt minimum battery voltage, 1.0 voltage drop, 10.5 minimum voltage to loads).

    It is not going to hurt to use extra heavy cables--but if you have any distance to run, the copper costs can get expensive very quickly.

    A 12 volt system, you do not want to support much more than 1,200 watts of maximum power--That is:
    • 1,200 watts * 1/0.85 inverter eff * 1/10.5v cutoff * 1.25 NEC safety factor = 168 amp minimum circuit wiring
    Around a 175 amp fuse and wiring.

    And if 1,200 watts is your maximum surge load, a good minimum battery bank rating would be:
    • 1,200 watts * 1/0.85 inverter eff * 1/10.5v cutoff * 2.5 max surge = 336 Amp*Hour @ 12 volt battery bank
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
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    Re: Need help with controller and 100v open panels

    Hi FF,

    I feel for you regarding the high voltage panels ... they are a bit difficult to use in battery based systems.

    Regarding using common AC line breakers on DC, Square D has a few breakers which are rated at 48 VDC -- the QO and the QOB, in current ratings above 10 Amps. However, I would not recommend it.

    The Square D breakers and boxes seem to be harder to find at the home improvement centers.

    For use on your solar panels (PV), the following breaker is inexpensive:
    http://www.solar-electric.com/mnepv.html

    It is designed for solar use, and is rated for 150 VDC.

    Good luck with your solar system. Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • firefly101
    firefly101 Registered Users Posts: 20
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    Re: Need help with controller and 100v open panels

    Thanks Vic for the information on DC breakers.

    I was thinking of using the Breakers here for the panels so its good to know that those would be a cost effective solution.

    Bill,

    Thanks as always for the information, I didnt plan to add a wind turbine until I get more batteries. My Battery bank would be probably 4 6v 110amp batteries by then. Do you think 440amp would be OK with the 1000w surge?

    For now I am going with 2 6v 110amp batteries as you suggested. But later I may just get the heavy duty 300amp 6v batteries and get 2 of them which would give me 600amps.

    I guess standard 4awg cable for the batteries would be best. I plan on having the controller Close to the Battery bank and same with the inverter. So the only lengths of cable will be the 71v panels and the 110v from the inverters. On the Panels I should be able to use old extension cord since its water proof outdoor and handles 110. This of course would only be used to connect each solar panel to the combiner/breaker box as they are only 15amp rated.

    I will use heavy duty 110v 30+ amp cable leading to the controller to handle the combined 24amps on a sunny day.

    Does it look like I am getting close to a good system setup yet? :confused:
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
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    Re: Need help with controller and 100v open panels
    firefly101 wrote: »
    My Battery bank would be probably 4 6v 110amp batteries by then. Do you think 440amp would be OK with the 1000w surge?
    Yes, that would be fine (see the C/2.5--battery capacity in AH divided by 2.5 for maximum surge current discussion).
    For now I am going with 2 6v 110amp batteries as you suggested. But later I may just get the heavy duty 300amp 6v batteries and get 2 of them which would give me 600amps.
    Two issues.

    First, adding new batteries to old batteries is not recommended. Also adding mixed battery capacity/brand/type is not recommended either. Batteries are very precise in their operation voltage (a 1/10 volt difference in resting voltage is, roughly, 10% difference in state of charge). It certainly can be done, but the new batteries may not last as long or share current properly with the parallel strings.

    Second, I am not sure you are adding AH correctly with series and parallel connections.

    Adding two batteries in series adds their voltage, but the AH rating remains the same (2x 6 volt @ 300 AH becomes a 12 volt @ 300 AH battery bank).

    When you have two batteries in parallel the voltage remains the same and the AH capacity adds (2x 6 volt @ 300 AH becomes a 6 volt @ 600 AH battery bank).
    I guess standard 4awg cable for the batteries would be best. I plan on having the controller Close to the Battery bank and same with the inverter. So the only lengths of cable will be the 71v panels and the 110v from the inverters. On the Panels I should be able to use old extension cord since its water proof outdoor and handles 110. This of course would only be used to connect each solar panel to the combiner/breaker box as they are only 15amp rated.

    Yes, this is a good plan. As always, "run the numbers" for voltage/current/wire gauge through a voltage drop calculator to ensure that you are not loosing too energy with longer wire runs (try for 3% maximum voltage drop).
    I will use heavy duty 110v 30+ amp cable leading to the controller to handle the combined 24amps on a sunny day.

    Remember that for MPPT type charge controllers, the solar array current is Power=Volts*Amps -- So, if you 6x the Vmp-array voltage (i.e., 71 volts at the array vs 12 volts at the battery), the current going through the Varray to Charge Controller wiring is ~1/6th the current going through the wiring from the Charge Controller to the battery bank for example (just random numbers).

    3x 71 watt panels with Vmp=71 watts and Imp=1 amp with a 12 volt battery bank:
    • Power = Volts * Current = 71v * 1a = 71 watts
    • Iarray = 3x 1a = 3 amps
    • Ibattery = 3x71 watts / 14.5 volts charging = 14.7 amps
    So, on the solar array side, the wiring carries ~3 amps and the battery cabling side carries ~15 amps in the above example (note, this only applies to MPPT type charge controllers. PWM chargers have current in equals current out).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • firefly101
    firefly101 Registered Users Posts: 20
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    Re: Need help with controller and 100v open panels

    Yes I made a mistake on my battery amps. I meant the following.

    The 6v I am getting are 220amp each which is why I though they would be good for my system, that is where I got the 440 for 4 6v 220amp batteries.

    Well the voltage for the 80w Panels amps are max 1.27 each and I have 4 of them. So I figured a Breaker leading to the Battery should be around 30amps to be safe and from the panels a simple 10amp breaker should do?

    For the panels breakers I think I can just use the Midnight ones sold here that some linked in this thread.

    Sounds like I should go with 4 220amp batteries later because I will probably get the wind turbine the end of this Autumn, so they batteries I get this summer shouldnt be classified as old or would they?

    Do you have a link to a voltage calculator to make life easier?

    I got to admit its nice having thes answers because if I just follow exactly what you guys say I will have a nice working system because your experience is worth gold. ;)
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
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    Re: Need help with controller and 100v open panels
    firefly101 wrote: »
    Well the voltage for the 80w Panels amps are max 1.27 each and I have 4 of them. So I figured a Breaker leading to the Battery should be around 30amps to be safe and from the panels a simple 10amp breaker should do?
    • 4x 80 watt panels * 1/11.0 volts * 1.25 safety * 1.25 NEC = 45 amp circuit/fuse minimum
    That would be for a TS MPPT 45 amp controller (or larger) with 320 watts of panels.
    For the panels breakers I think I can just use the Midnight ones sold here that some linked in this thread.
    Solar panels are really current sources--They do not output much more than Isc...And typically have a maximum series fuse/breaker of ~2xIsc.

    I don't think you need a circuit breaker for the solar array (the panels cannot output more than ~Isc). Although the NEC requires an array disconnect switch.

    If you have more than two panels in parallel, you should have an Iseries fuse in each parallel connected panel (4 parallel panels, 4 fuses in each positive lead). This is to prevent a short in one panel from being fed too much current by the other three panels. You can build your own fuse holder/box or buy a "combiner box".

    Check the data sheet for your panels and see what the series fuse rating is.
    Sounds like I should go with 4 220amp batteries later because I will probably get the wind turbine the end of this Autumn, so they batteries I get this summer shouldn't be classified as old or would they?
    I would not stay up late and worry about adding two (relatively inexpensive) batteries 1 year later. Ain't ideal... But will not blow up or stop working the next day.
    Do you have a link to a voltage calculator to make life easier?
    There are a lot out there--But this one seems to be close enough--and I just pick wire gauge to get the right voltage drop. I ran across a nice NEC based one--but it took quite a while to figure out how to run it.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • firefly101
    firefly101 Registered Users Posts: 20
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    Re: Need help with controller and 100v open panels

    Thanks will do on the breaker, 45 amp it is. Should be too bad on that now that I got a brand to look up.

    On the fuse for the panels I need to get 100v compliant fuses any suggestions where and the holders?


    I'm doing all this while doing a 1550gal water Tank system, so I am bouncing around between projects. lol

    Both are new to me and have new things and tricks to learn.

    This forum is a great source of help and information. I wish more knew about it, as it would save them alot of headaches and failures.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
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    Re: Need help with controller and 100v open panels

    If you think that you might add more panels later, you might as well make the breaker the recommended maximum for the TS 45 mppt (60 amps or so--what ever the manual says). You will just be using a little bit heavier wire to the battery. 45 amp is not a standard fuse size anyway.

    This is one example of a commercial combiner box.

    Up to 8 amps, AGC fuses are rated to 250 volts.

    You can get an inexpensive 6 position AGC fuse holder and make your own enclosure:

    http://primeproducts.com/electrical-c-43.html

    Similar questions from the Balanced System? thread.

    We all start learning from somewhere.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • firefly101
    firefly101 Registered Users Posts: 20
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    Re: Need help with controller and 100v open panels

    Thanks! That helps alot.
  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
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    Re: Need help with controller and 100v open panels

    Bill would you worry about his insurance, using non UL rated holders? He's mounting these on his roof, so I'd recomend UL rated are available, they're in my boxes, I think I have one open, I'll pull it and let you know make/model, or I'll do a search when I get home tonight.

    New NEC this year? Did Wiles get his no-touch exposed connections through? I think the term is dead front, were if you open the front there still is no exposed wire connections. I think he wanted all fusing to be in no touch holder, but there were no UL listed holders in '08 last codes revised.
    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: 33,439 admin
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    Re: Need help with controller and 100v open panels

    I don't know. Sort of have the maximum to minimum price range.

    If fuses are installed, I would think it would not be questioned unless the holder was the source of the fire.

    UL is a no-brainer defense. Non ul does not mean an automatic loss in court.

    I am still working on the nec dc ground fault issue right now. Proper grounding would sure reduce the need for no touch fuse holders.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • firefly101
    firefly101 Registered Users Posts: 20
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    Re: Need help with controller and 100v open panels

    Any help is welcome. Pictures are great also. ;)

    It will make everything easy to know exactly what to get at home depot. You know you can never get help there, so if you dont know exactly what you need you will never find it. lol