possible starter system

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  • BoFuller
    BoFuller Solar Expert Posts: 187 ✭✭✭
    Re: possible starter system

    By the way, it got too late and I had to head home, so I didn't get a chance to look at the original trailer inverter/transformer yesterday after equalization.
    And after equalization I had hydrometer readings of;
    1.260
    1.250
    1.250
    1.250
    1.250
    1.250

    Still not close to 1.30 that I was expecting. The Trimetric said equalization ran for 3 hours at 15.9V, with amperage starting at 12.9 and dwindling down to 4.6
    12 Kyocera 235 panels, 3 Gyll LiFePO4 batteries (previously 16 Trojan L16 RE-B batteries), Outback 3600W 48V system, Generac 11K propane backup generator, NW AZ, off grid, 6,000 ft (system installed in April 2015)

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: possible starter system

    :confused: Why were you expecting SG of 1.300? Normal is 1.275, and things like temperature, elevation, and the particular hydrometer used will vary that.

    When you run an EQ cycle you should do it for an hour at a time, recheck, and repeat until no improvement is seen. Merely setting it to run for three hours could subject the batteries to a lot of heat stress (and water loss) they don't need.

    The one cell difference of 0.010 is probably an aberration of no consequence.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: possible starter system
    BoFuller wrote: »
    I need to do some investigating. My neighbor doesn't think I have two inverters. He thinks the unit already in the trailer is just a step-down transformer to provide 12 volt from the shoreline.

    This is probably a converter/charger, often found in RV's.
    There are different possible options for hooking up my system in the RV trailer.

    Currently I have the old leads that went to the trailer batteries (for 12 volt), connected to the 250 amp breaker and the shunt, so they are getting power straight from the new batteries.

    One guy said I should just disconnect them and continue to use the transformer/converter that came in the trailer. So I would have 12 volt coming from the batteries, have my new inverter switch it to 120V, send that 120V to the transformer/inverter and have it continue to provide the 12 volt power. That would mean that the new inverter would be running 24/7 and I would have a little loss on efficiency.

    This would be wrong. Power 12 Volt loads from the batteries. Recharge the batteries from solar or the converter/charger fed from shore power. Do not try to convert battery power to 120 VAC and then back to 12 VDC to run the DC loads. Unstable DC and a waste of battery power for the extra conversions.
    Or I could leave the 12 volt lines connected to the new batteries and run the 120 line to the 120 fuse box and bypass the original transformer/inverter altogether.

    You need to do it right: that thing you call a transformer/inverter is probably an inverter/charger. Does the new inverter have a built-in charger? (Forgive me if I haven't kept track.) If not, you need this method of recharging the batteries from shore power just in case. If so, you don't need anything other than the new inverter/charger.
    If I run everything through the new inverter then my Magnum Remote would be giving me readings on all the power. If I do it the other way, I still should be monitoring the power with my Trimetric meter, since I connected to the shunt instead of directly to the batteries.

    Thoughts?

    The best way to keep track of the batteries is to run all DC power through the Trimetric's shunt. That way no matter where it comes from or where it goes to it will be accounted for.
  • BoFuller
    BoFuller Solar Expert Posts: 187 ✭✭✭
    Re: possible starter system

    I didn't set the time. I just pressed the Equalize button on the Morningstar CC and monitored it until it quit.
    You are the first to tell me that I shouldn't expect 1.3. I have had several people with that battery tell me I should be at or very close to 1.3 when new.
    12 Kyocera 235 panels, 3 Gyll LiFePO4 batteries (previously 16 Trojan L16 RE-B batteries), Outback 3600W 48V system, Generac 11K propane backup generator, NW AZ, off grid, 6,000 ft (system installed in April 2015)

  • BoFuller
    BoFuller Solar Expert Posts: 187 ✭✭✭
    Re: possible starter system

    That's sort of what I thought. It didn't make sense to me to convert twice.
    When I go back up on Thursday I'll see about disconnecting the old original inverter.
    And yes the new inverter has a charger also.

    Thanks again!!!
    12 Kyocera 235 panels, 3 Gyll LiFePO4 batteries (previously 16 Trojan L16 RE-B batteries), Outback 3600W 48V system, Generac 11K propane backup generator, NW AZ, off grid, 6,000 ft (system installed in April 2015)

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: possible starter system

    Trojan's actual spec is 1.280, which is pretty close to 1.275

    The data sheet for the L16RE-B: http://www.trojanbatteryre.com/PDF/datasheets/L16REB_TrojanRE_Data_Sheets.pdf
  • BoFuller
    BoFuller Solar Expert Posts: 187 ✭✭✭
    Re: possible starter system
    Trojan's actual spec is 1.280, which is pretty close to 1.275

    The data sheet for the L16RE-B: http://www.trojanbatteryre.com/PDF/datasheets/L16REB_TrojanRE_Data_Sheets.pdf

    Good to know. I'm not that far off after all.

    Thanks!!
    12 Kyocera 235 panels, 3 Gyll LiFePO4 batteries (previously 16 Trojan L16 RE-B batteries), Outback 3600W 48V system, Generac 11K propane backup generator, NW AZ, off grid, 6,000 ft (system installed in April 2015)

  • BoFuller
    BoFuller Solar Expert Posts: 187 ✭✭✭
    Re: possible starter system

    I just got back up to the Ranch. I was trying to disconnect the converter that came with the trailer and it's next to impossible to get into the tight space. After trying for awhile I came across another idea. Just pull the 40 amp fuse from the back of the converter. I pulled it out and then turned on the new converter and it seems to be working fine. No more pulling 25 amps. I believe it is less than 3 amps now. Does this sound okay?
    12 Kyocera 235 panels, 3 Gyll LiFePO4 batteries (previously 16 Trojan L16 RE-B batteries), Outback 3600W 48V system, Generac 11K propane backup generator, NW AZ, off grid, 6,000 ft (system installed in April 2015)

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: possible starter system

    It is getting better--But not "good enough" yet...

    You are drawing ~12.5 volts * 3 amps * 0.85 inverter eff = 32 Watts AC

    Your inverter should draw 6-12 watts or so unloaded--So, it is very possible that your Converter is still connected to the AC input and drawing 10-20 watts or so (the 40 amp fuse is probably for the 12 VDC output--You have stopped charging the battery with your inverter--but you are probably still driving the converter's AC input circuitry).

    Look for a fuse/breaker/etc. that is connected to the converter--You should be able to kill it there--If not, you still should disconnect the AC input to the converter.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BoFuller
    BoFuller Solar Expert Posts: 187 ✭✭✭
    Re: possible starter system

    So now I'm planning my system for the cabin. Just when I think I understand something, somebody says something that totally confuses me.
    If I want the cabin system to be able to produce about 3KW per day, how many panels (235W) do I need? I'm thinking 13 to 15.
    And probably 10-12 L16RE-Bs?
    12 Kyocera 235 panels, 3 Gyll LiFePO4 batteries (previously 16 Trojan L16 RE-B batteries), Outback 3600W 48V system, Generac 11K propane backup generator, NW AZ, off grid, 6,000 ft (system installed in April 2015)

  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
    Re: possible starter system
    BoFuller wrote: »
    So now I'm planning my system for the cabin. Just when I think I understand something, somebody says something that totally confuses me.
    If I want the cabin system to be able to produce about 3KW per day, how many panels (235W) do I need? I'm thinking 13 to 15.
    And probably 10-12 L16RE-Bs?

    You need about 15 panels to produce 3 kilowatts of DC power. Kilowatts (power) is not the same as kilowatt-hours (energy). To get kilowatt-hours, look up your equivalent direct sun-hours on a chart (like the NREL charts) and multiply your power by number of hours. That gives you DC energy, which in your case will be around 21 kilowatt-hours a day (NW Arizona). To figure out your AC energy available you have to factor in inverter and charging efficiencies. Will probably average around 16-18kwhr available in that case.
  • BoFuller
    BoFuller Solar Expert Posts: 187 ✭✭✭
    Re: possible starter system
    You need about 15 panels to produce 3 kilowatts of DC power. Kilowatts (power) is not the same as kilowatt-hours (energy). To get kilowatt-hours, look up your equivalent direct sun-hours on a chart (like the NREL charts) and multiply your power by number of hours. That gives you DC energy, which in your case will be around 21 kilowatt-hours a day (NW Arizona). To figure out your AC energy available you have to factor in inverter and charging efficiencies. Will probably average around 16-18kwhr available in that case.

    So then for 3 KW hours I only need 3 PV's?
    3 X 235 = 705 X .85 = 600 X 6 hours = 3600 = 3.6 KWH?
    12 Kyocera 235 panels, 3 Gyll LiFePO4 batteries (previously 16 Trojan L16 RE-B batteries), Outback 3600W 48V system, Generac 11K propane backup generator, NW AZ, off grid, 6,000 ft (system installed in April 2015)

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: possible starter system

    Using PV Watts for Las Vegas (is your weather more like Vegas or Flagstaff?), fixed array, derating of 0.52 (inverter, flooded cell battery bank, etc.), 1kW array, we get:
    "Station Identification"
    "City:","Las_Vegas"
    "State:","Nevada"
    "Lat (deg N):", 36.08
    "Long (deg W):", 115.17
    "Elev (m): ", 664
    "PV System Specifications"
    "DC Rating:"," 1.0 kW"
    "DC to AC Derate Factor:"," 0.520"
    "AC Rating:"," 0.5 kW"
    "Array Type: Fixed Tilt"
    "Array Tilt:"," 36.1"
    "Array Azimuth:","180.0"

    "Energy Specifications"
    "Cost of Electricity:"," 9.7 cents/kWh"

    "Results"
    "Month", "Solar Radiation (kWh/m^2/day)", "AC Energy (kWh)", "Energy Value ($)"
    1, 5.19, 79, 7.66
    2, 5.98, 80, 7.76
    3, 6.57, 98, 9.51
    4, 7.32, 103, 9.99
    5, 7.42, 105, 10.18
    6, 7.35, 96, 9.31
    7, 7.37, 98, 9.51
    8, 7.29, 97, 9.41
    9, 7.31, 96, 9.31
    10, 6.56, 94, 9.12
    11, 5.75, 83, 8.05
    12, 5.05, 77, 7.47
    "Year", 6.60, 1106, 107.28

    I like to throw out the lowest 3 months (assume generator for backup power--although in Las Vegas, 5 hours of sun per day ain't bad), gives us February:
    • 80 kWH per 1kW of panel / 28 days in Feb = 2.86 kWH per day per 1kW of panels in February (long term average)

    If you want 3 kWH per day, then using the above we get:
    • 3 kWH desired (Feb) / 2.86 kWH per 1 kW of panels = 1.05 kW = 1,050 Watts of solar panels to meet your minimum load

    Of course, you should not use 100% of your daily needs--Perhaps 75%... So you can can add a bit of solar array (1/0.75 = 1.33x larger array) if you really want a "hard" 3+ kWH per day in February (or more, if you want to assume 5.05 hours of minimum sun for 12 months of year--depends on your loads and occupation dates).

    The "ideal" battery bank... Assume 1-3 days no sun (use 2 days for nominal design) and 50% minimum discharge. Start with 24 volt bank:
    • 3,000 WH * 1/0.85 inverter efficiency * 1/24 volt battery bank * 2 days no sun * 1/0.50 max discharge = 588 AH @ 24 volt battery bank

    We recommend around 5% to 13% rate of charge for a battery bank (yes there are arguments for larger or even smaller--just starting rules of thumb):
    • 588 AH * 29 volts charging * 1/0.77 panel+charger efficiency * 0.05 Rate of Charge = 1,107 Watt Array minimum
    • 588 AH * 29 volts charging * 1/0.77 panel+charger efficiency * 0.10 Rate of Charge = 2,215 Watt Array "nominal"
    • 588 AH * 29 volts charging * 1/0.77 panel+charger efficiency * 0.13 Rate of Charge = 2,879 Watt Array "cost effective maximum"

    Now, because you have so much sun, a pretty small solar array will do very nicely supplying power even in winter for you... So, it turns out the size of the solar array is really being "forced" by the size of the battery bank and recommended charging rates.

    You do have the option of going with a smaller battery bank, especially if you have few cloudy days--But that may limit your maximum surge current (important if you have pumps).

    Or you can go with a larger array and get upwards of 6kWH per day of power (sunny weather) even in February.

    Lots of choices.

    Regarding your choice of batteries (10-12 L16 REB's), those are 6 volt * 375 AH... And given your choice of 10 batteries--that would indicate you are thinking about a 12 volt system... I would suggest against that as you will need very heavy wire and upwards of 2x fairly expensive MPPT charge controllers.

    Instead, I would suggest you consider using a 24 or even 48 volt battery bank... Your DC current will be much less and you use use a single 60 Amp MPPT charge controller (I personally recommend trying for 1 string of batteries, and 2-3 strings maximum in parallel. Lots of maintenance/operational issues with massively parallel battery banks and proper current sharing, checking fluid levels, etc... Although, there are people happy with 3+ parallel strings).

    Anyway, you could use a smaller battery--But lets look at using Trojan L16RE-A 325 AH 6 volt batteries:
    • 24 volt 650 AH bank: 2 parallel strings of 4x L16REA batteries in series (8 batteries total)
    • 48 volt 325 AH bank: 8x L16REA batteries in series (8 batteries total)

    My two cents worth...

    By the way, how much do you know about your loads (average "maximum" Wattage, maximum surge Watts, etc.). Helps to size the battery bank and AC inverter.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: possible starter system
    BoFuller wrote: »
    So then for 3 KW hours I only need 3 PV's?
    3 X 235 = 705 X .85 = 600 X 6 hours = 3600 = 3.6 KWH?

    Possibly more like:
    3kW hours, 52% over-all system efficiency, 4 hours of "equivalent good sun": 1442 Watt array.
    About 500 Amp hours of battery on a 24 Volt system @ 25% DOD.

    The one big variable is whether or not you can get 6 hours of equivalent good sun year-round. It never hurts to be a little bit cautious. :D
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: possible starter system
    BoFuller wrote: »
    So then for 3 KW hours I only need 3 PV's? ......

    That all depends on the size of the PV's Think watts, not # of PV's
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BoFuller
    BoFuller Solar Expert Posts: 187 ✭✭✭
    Re: possible starter system
    mike90045 wrote: »
    That all depends on the size of the PV's Think watts, not # of PV's

    I already have nine (9) panels so I could have 9 X 235 = 2115 X .70 = 1480.5 X 4 hours (minimum, probably 5 to 6) = 5922 KWH at least, and as high as 8989.

    As for the battery bank, I have no preference at this time. Definitely not a 12 volt system. Either 24 or 48, but I'm not decided.
    Solar array to be on a pole about 60 feet from house/battery bank. Possibly 8 L16RE-B 370? Like 2 parallel strings of 4 batteries?
    Thoughts?
    12 Kyocera 235 panels, 3 Gyll LiFePO4 batteries (previously 16 Trojan L16 RE-B batteries), Outback 3600W 48V system, Generac 11K propane backup generator, NW AZ, off grid, 6,000 ft (system installed in April 2015)

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: possible starter system

    When you're planning an off grid system you need to start with the load requirements. If those requirements are 3 kW hours per day, you plan a battery bank that will store that much at least. This must include the DC to AC conversion loss and the power required to run the inverter itself. Thus 3 kW hours AC becomes more like 3800 Watt hours DC.

    To get that on a 24 Volt system you need (3800 / 24) 158 Amp hours. At 50% DOD that's 316 Amp hour battery bank. 25% DOD is a better target, and would require 632 Amp hours. On a 48 Volt system it would be half those capacity numbers because the Voltage is doubled.

    Then you plan the array to recharge those batteries and supply the Watt hour needs. Ordinarily this would be based on 5% - 10% - 13% of the battery bank capacity. So for the 24 Volt 632 Amp hour bank you'd look for 63 peak charge Amps which you get from about 2 kW array (63 * 24 = 1512 Watts @ 77% typical efficiency = 1963 Watt array).

    Your 2115 Watt array would work here. In fact it could support a slightly bigger battery bank. You are looking at over 60 Amps charge current potential here, so you'd need a controller that can handle that (like an FM80).
  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: possible starter system
    BoFuller wrote: »
    Definitely not a 12 volt system. Either 24 or 48, but I'm not decided.
    Solar array to be on a pole about 60 feet from house/battery bank.
    Possibly 8 L16RE-B 370? Like 2 parallel strings of 4 batteries?
    Thoughts?

    If you need the energy storage of eight L16s, I suggest you put them in series and go 48 volts.

    Also, since your panels are 60 ft from the controller you want to have a high voltage going to the controller to minimize cable loss. However, your controller will be more efficient if the ratio of volts in to volts out is not too high. In other words, if you configure your panels to have 100 volts going to the controller, you are better off converting that 100 volts to 48 volts than 24 volts.
    To see some real numbers, check out: http://forum.solar-electric.com/showthread.php?15907

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • BoFuller
    BoFuller Solar Expert Posts: 187 ✭✭✭
    Re: possible starter system

    So for the last couple months my system has been running fine. When we are there for several days, the meter seldom goes below 80%, usually around 88% in the morning. My concern is the coming winter and decrease in sun. My panels are bolted flat on the roof of the travel trailer now and that is fine, but I know I will need them tilted in the winter. I don't think the roof of a travel trailer is strong enough to support the panels if I put adjustable brackets under them. I fear a strong wind will just rip them and part of the roof right off the trailer. I was thinking of putting a pole next to the trailer and mounting the panels vertically for the winter, or mounting 3 more panels (I have about 9 more in the garage) on a pole and just connecting it during the winter months.

    Can I put another string of 3 on the existing system and add it in, or should I just use three mounted vertically and disconnect the flat ones?
    12 Kyocera 235 panels, 3 Gyll LiFePO4 batteries (previously 16 Trojan L16 RE-B batteries), Outback 3600W 48V system, Generac 11K propane backup generator, NW AZ, off grid, 6,000 ft (system installed in April 2015)

  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: possible starter system
    BoFuller wrote: »
    Can I put another string of 3 on the existing system and add it in, or should I just use three mounted vertically and disconnect the flat ones?

    Your controller can handle another string of 3 panels. I see two issues. Vertical panels work well when there is snow on the ground. Without snow I wouldn't recommend vertical orientation. Whenever you have panels connected together with different orientations you may confuse the MPPT controller... there will be more than one max power point.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • BoFuller
    BoFuller Solar Expert Posts: 187 ✭✭✭
    Re: possible starter system

    Snow is one of my major considerations. So I might be better off mounting 3 panels vertically (or close to it) and plugging them in instead of the current flat array. Since I have other panels, it would be easier to mount 3 new ones than to try and move the ones attached to the trailer.
    12 Kyocera 235 panels, 3 Gyll LiFePO4 batteries (previously 16 Trojan L16 RE-B batteries), Outback 3600W 48V system, Generac 11K propane backup generator, NW AZ, off grid, 6,000 ft (system installed in April 2015)

  • BoFuller
    BoFuller Solar Expert Posts: 187 ✭✭✭
    Re: possible starter system

    Normally when I am staying here at the Ranch, whether for a weekend or a couple weeks, my SOC usually gets down to 82 to 86%. Reading somewhere on this site a little while ago, it was mentioned that it was good to go down lower, say to 70 or 60 once in a great while. I was at 78 this morning and decided to use the microwave instead of the stove, just to get the SOC lower. I set it for 3 minutes to boil water and part way through it shut off. The Magnum remote meter shut off the inverter and said that 76 was the SOC lowest allowed. A fault light came on and I couldn't use my inverter for about a half hour. Fortunately it was 7:00 am and the sun was starting to charge. How can I go lower than 76 SOC if I choose to?
    12 Kyocera 235 panels, 3 Gyll LiFePO4 batteries (previously 16 Trojan L16 RE-B batteries), Outback 3600W 48V system, Generac 11K propane backup generator, NW AZ, off grid, 6,000 ft (system installed in April 2015)

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: possible starter system

    I am not sure--You have a meter interface that, I would hope, would allow you to program the minimum battery SOC cutoff...

    However, there is the "Advanced Meter" that does give you access to more programming registers (as I understand)--If you do not find the settings with the RC meter:

    wind-sun_2229_13548354Magnum ME-ARC50 Advanced Remote Control for Magnum Inverters 50' Cable

    The ME-ARC is simple to use, yet allows full set-up of all the standard and advanced features available in Magnum inverters. The ME-ARC also has the option of controlling the advanced features of the ME-AGS-N Automatic Gen Start and the ME-BMK Battery Monitor Kit using a network connection to the inverter. This remote has convenient finger-tip operation, including the new one-knob programming.

    Note: All settings/setup menus in the ME-ARC are compatible with MS-PAE Series inverter/chargers. If you are using the ME-ARC with another inverter/charger (other than the MS-PAE Series), some features and setup menus may not be compatible with your inverter and will not function. Contact Magnum Energy to determine if a particular feature/setup menus provided in the ME-ARC are compatible with your inverter.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: possible starter system

    the default low battery cut off voltage (lbco) is set at the factory at 10v for the ms2012. this is quite low and may indicate an extreme draw on the batteries pulling the voltage down or the batteries aren't in as good of shape as you think or both. be very sure of soc by the specific gravity. if sg is fine then the draw was just too great for the batteries to handle (i suspect this as microwave ovens can pull between 1000w and 1500w) and as a result pulled the voltage way down. large loads will also cause any weak areas of the system to rear their ugly heads such as bad connections or connectors and undersized wires.

    now you do have the remote and i suggest you go through its settings to see if it was changed as it can be set between 9v and 12.2v.
    see page 9 in the manual
    http://www.magnumenergy.com/Literature/Manuals/Remotes/64-0003 Rev E (ME-RC).pdf