Trailer solar application

newmexico
newmexico Registered Users Posts: 7
First of all great forum..

I'm charged with getting the supplies needed to put solar on a trailer to be used as a remote work station. I would like to just go to the sponsors of this forum's brick and mortar store and ask them, but it's too far away. I've come up with with a list of items that I think will work together, but I'm no expert. Here's the list with the basic Items that I'm looking at.

Two Kyocera KD135GX-LP solar panels $670 each

Either parallel wiring Blue Sky 2000E MPPT Charge Controller 25 amp $225 OR

Series wiring Blue Sky SB3024i MPPT Charge controller 30 amp $322 OR

Series wiring Morningstar SS-MPPT-15. 15 Amp, 12 or 24 Volt Solar Charge Controller
with a remote battery temp sensor.

MC4 cables to connect the panels together and the cable to run to the charge controller Two 6 ft sections $18 each--- and two 50 foot sections $40 each.


two Trojan T-105 six volt batteries in series for 12 volts 240 amp hours.

I'm wondering if there are any obvious mismatches in the size of these components, and also if there are any other components needed to make things work... i.e in line fuses etc.

Thanks

Comments

  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Trailer solar application

    Just a quick look at your hardware needs, The two panels will put out ~ 270 watts~22 amps, not a lot of headroom for a 25 amp controller.

    Same panels @ 24vdc would put out ~11.25 amps,, not a lot of headroom for a 15 amp controller.

    I would also always consider temp control on any controller, especially if the batteries are subjected to cold or hot extremes.

    Good luck,

    Tony

    Panel specs:
    Specifications for Kyocera KD135GX-LP Solar Panel
    Max Rated Power (Pmax) 135 Watts
    Voltage at Max Power (Vmpp) 17.7
    Current at Max Power (Impp) 7.63 Amps
    Open Circuit Voltage (Voc) 22.1
    Short Circuit Current (Isc) 8.37 Amps
    Length x Width x Depth (inches) 59.1 x 26.3 x 1.4
    Weight of Panel (Pounds) 28.7
    Connector Cable Type or Junction Box MC4 Latching Cables
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Trailer solar application
    newmexico wrote: »

    Series wiring Morningstar SS-MPPT-15. 15 Amp, 12 or 24 Volt Solar Charge Controller
    with a remote battery temp sensor.

    two Trojan T-105 six volt batteries in series for 12 volts 240 amp hours.

    I'll give my opinion on 2 items:

    the MS 15A MPPT controller will be at it's limit, it will likely limit for some period every day, (30 minutes?) but Solar Guppy http://forum.solar-electric.com/showpost.php?p=18981&postcount=14
    claims this is within it's capability, and mostly harmless. You will loose little annual power with this. I'm counting on 80% of STC output to arrive at this S.W.A.G.
    135x2 x.8 =216W / 14V = 15.4A That would only limit at the peak half hour of *perfect* solar alignment. No room for expansion of adding another panel. As solar starts off slow, at sunrise, when batteries can take the most charge, the Panels will not have a lot of power yet. They have to be perpendicular to the sun to get their rated power, and cool to the touch. As the batteries fill up, their voltage rises, and you will only see occasional limiting. My nickels worth of free advice.



    To preserve battery life, your 240A batteries should only be drained to 50%, giving you 120AH of usable power.
    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 ,

  • BB.
    BB. Super Moderators, Administrators Posts: 33,404 admin
    Re: Trailer solar application

    My nickel's worth (inflation)...

    How much power do you need and where will the installation be... You can have any amount of panels and batteries--but if it is not enough electricity--then you are hosed and will need another source or to ration your power...

    And yes, you will need fuses--they are sized for the gauge of the wire you are protecting--and your load current should be low enough that you don't get a lot of voltage drop... 12 volts of power, 1 volt drop from a 10 amps of current for a few 10's of feet of run--and you are probably under 11 volts at the load--most loads would consider 10.5 volts to be a dead battery. Fuses and wire runs add voltage drop...

    If you are sending power a long(ish) distance--using an good, small, inverter to power the loads as AC may not be the worst thing in the world.

    Also, a deep cycle battery system has quite a wide swing of valid operation, from 10.5 volts (heavy loads/dead) to 15.5 volts when equalizing (wet cell batteries)--many "car type" DC power adapter will not perform well in these types of applications (frequently they fail when operated much above 14 volts--car charging voltages).

    Battery monitor
    --Hardly anyone can read a hydrometer properly--and most will not bother using one until the batteries have died once or twice--plus the issue of contamination and loss of electrolyte if people are not careful.

    A battery monitor becomes as simple as reading a fuel gauge. Anyone can do it, and the newer ones can be programed to signal when you are below 50% of battery capacity (new Xantrex "Link***" series is one)--or you can use it to turn off the loads until the batteries are recharged.

    You might also look at using water miser type caps for your batteries--If you are in the middle of nowhere--distilled water (a cup or so per battery per month?) might be a big issue.

    Or, look at AGM's---as long as you have a properly programed charge controller and battery temperature sensor--they should be very nice for this application.

    Just to double check how much power you expect... Try playing with this link. Assuming Albuquerque NM, and 0.52 derating (use 0.59 if DC only--no inverters):

    1kW of panels will give you around 80-100 kWhr per month or around 3kWhrs per day (+/-). 270 watts of panels, about 1/4 of that... or ~0.91kWhrs or 910 watt*hours per day...

    At 12 volts, then 810/12=67.5 Amp*hours per day... (about 8 months of the year)...

    Is that how much power you need?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • newmexico
    newmexico Registered Users Posts: 7
    Re: Trailer solar application

    Thanks for all the advice.

    Bill, the installation won't be very far from town and we have four t-105's sitting around two of one age, two of a different age. So no AGM's (but they do seem to be nice). We don't need much power-- propane cooking, propane refrigerator.. So lights, maybe a laptop occasionally, shoe dryers and perhaps the blower on the furnace once in a great while. The trailer will be in use for only the late Spring, Summer, and early Fall months, but it can still get cold at 9000 feet.

    The Battery Monitor is a great suggestion-- The little lights on the trailers that supposedlly show battery condition certainly aren't the best; especially when you get a crew of different people every year to use the trailer. Probably should get a Kill-a-watt as well....

    Basically the trailer is to be a cooking, get out of the rain shelter, watch movies on laptops. So we will limit power usage to how much the sun will give us with the two panels.

    So, revised list is

    Two Kyocera KD135GX-LP solar panels 7.39ampsX2=14.8 or
    135x2 x.8 =216W / 14V = 15.4A wired in series to a

    Blue Sky SB3024i MPPT Charge controller 30 amp with a Battery Temp sensor

    Xantrex LinkLite battery monitor

    Two Trojan t-105's

    Just enough MC4 cable to connect the panels together on roof of trailer and then run to the charge controller. (I'm assuming it's better to run 24+ volts a longer distance to the charge controller outputting ~10-16 volts which will be near the batteries?)

    one Kill a Watt meter

    assorted fuses, connectors etc.

    and lastly some sort of inverter that will use energy just to convert from DC to AC for the laptops, shoe dryers, etc...

    I think this sounds reasonable?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,404 admin
    Re: Trailer solar application

    If you power "small" electronics and a few CFL and/or LED lights--you are probably OK (power a smallish laptop for well over 10 hours)...

    But when you add blower and shoe driers--you will need to watch those closely... Assuming a shoe drier is 300 watts (just a guess)--pretty much 3 hours and you used up the day's charging...

    Morning Star's new Solar Charger and 300 Watt AC inverter look pretty nice... Don't worry that your panel is 15.4 amps max rating... The controller will limit itself to a safe current and, in any case, 15.4 will be a relatively rare event unless you are running in the snow.

    Morning Star 15 amp MPPT controller (12/24 volt output)

    Morning Star 300 watt inverter

    It would be interesting to see if you can program the LinkLite to turn off the Morning Star inverter if the batteries are over discharged (with a bypass switch).

    Also, it may be worthwhile getting one of those 4 hour mechanical timers that you can have turn off the inverter when it times out--for those times when people forget and "leave the lights on"...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • newmexico
    newmexico Registered Users Posts: 7
    Re: Trailer solar application

    I came up with a list, gave it to my boss, and he said we can spend more money. I made a new list... The old one was

    TWO Kyocera KD135GX-LP 135 Watt 12 Volt Solar Electric Panel

    Morningstar SunSaver MPPT Solar Charge Controller
    Item# SS-MPPT-15

    Morningstar SureSine, 300 Watt Sine Wave Inverter 115VAC
    Item# SI-300-115V

    Xantrex LinkLITE Dual Battery Monitor
    Item# LinkLITE

    50 Foot MC4 Solarline 2, Extender Cable Male/Female
    Item# MC4-50-MF

    TWO 6 Foot MC4 Solarline 2, Extender Cable Male/Female
    Item# MC4-06-MF


    We have an existing trailer that could use some upgrades so I decided to add a couple of things for it as well..

    So New list is.....

    THREE Kyocera KD135GX-LP 135 Watt 12 Volt Solar Electric Panel

    Outback MX60 MPPT Charge Controller

    RTS - Outback Power Remote Temperature Sensor

    Xantrex LinkLITE Dual Battery Monitor

    50 Foot MC4 Solarline 2, Extender Cable Male/Female

    THREE 6 Foot MC4 Solarline 2, Extender Cable Male/Female

    To upgrade existing trailer that has two Kyocera’s --one KC125, one KC130 with BZ charger controller

    Morningstar SunSaver MPPT Solar Charge Controller
    Item# SS-MPPT-15

    Xantrex LinkLITE Dual Battery Monitor
    Item# LinkLITE

    I was wondering if a Battery Monitor is needed if you have the Outback MX60?

    Also any suggestions on a good inverter in the 1000 watt range for something like short periods with a vaccum cleaner.?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,404 admin
    Re: Trailer solar application

    Yes, the battery monitor is the only device out there than can accurately measure and display your battery bank's capacity--because it monitors current in/out just like an odometer on your car or a by-directional fuel flow meter connected to a gas tank (assuming you fill/drain take through the same pipe/meter).

    You can estimate battery capacity with an accurate voltmeter--but you have to use temperature compensation and let the batteries rest for 2-3 hours for anywhere close to accurate measurements (no load, no charging for 2+ hours).

    If you are using flooded/wet cell batteries, you can use a hydrometer and thermometer for very accurate battery monitoring--but that is something you are only going to do a few times a month. Or when trying to find out if you have a problem. If you use AGM--you don't have that option.

    For running a large load on occasion--like a vacuum cleaner--perhaps one of those $100 1kW modified square wave inverters will work just fine... They are not quite as efficient and can damage some appliances/electronics--but for a simple vacuum cleaner/electric drill/etc.... It will be just fine (you don't want to run a fridge, some electronics off of a Mod Sqwave inverter--but the problem is while 90% of devices will work ok, you won't know which 10% will not--some will get hot first, and you can disconnect them--others will just pop in hours to weeks of use--just cannot predict). I have used Mod-SqWave Inverters on small appliances for years (TV, radio, drill, lights) without problems--but for a long term installation--pure sine wave is much better.

    And, add up the loads--you may wish to add more solar panels, or get a Honda eu2000i or eu1000i + AC battery charger (like Xantrex or Iota) for backup/portable power... The eu2000i is very fuel efficient at 25% load--most "cheap" generators gulp down fuel at light loads just about as fast as at full load. I personally think the eu2000i is the best out there. Yamaha inverter generator would be another option, and there are import knock-offs too.

    For looking at generators, I recommend looking at their kWhr/gallon of fuel consumed numbers... The eu2000i from 400 watts to 1,600 watts (1/4 to full load using "ECO Throttle") gets over 5kWhrs per gallon of fuel... You can run the eu2000i at 400 watts on 1.1 gallons of fuel for some 15 hours...

    400 w * 15 hours / 1.1 gallons = 5,454 WattHours / gallon (5.45kWhr/gal)

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Trailer solar application
    For running a large load on occasion--like a vacuum cleaner--perhaps one of those $100 1kW modified square wave inverters will work just fine... They are not quite as efficient and can damage some appliances/electronics--but for a simple vacuum cleaner/electric drill/etc...

    Add the shoe dryer to a possible large load . Can you tell us more about it, and it's expected use cycle ?
    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 ,

  • newmexico
    newmexico Registered Users Posts: 7
    Re: Trailer solar application

    ahh, the shoe dryer(s) It's something called a PEET shoe dryer. Low heat, one advertisment on the web says that it uses less energy than a 40 watt light bulb.
    An 18 watt heating element. Going to have to run it through the Kill-A-Watt though and see what happens.


    http://www.muckbootsonline.com/Peet_Boot_Dryer_p/ptm9712sf.htm

    we may use two of them 6 hours a day, but if there's no extra energy in the batteries, then we'll just have to deal with wet feet...
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Trailer solar application

    80 watts for 6 hours makes for a pretty big draw=480 wh or ~40 ahrs/12vdc
    With my ~200 watt system, I use less than 40 ahrs on any given day, total. I keep from drawing down my bank more than 20% (80%soc). With the 40 ah draw I get it back almost every day, but I have about 3 days reserve if there is no sun. In that case it may take two days to get back.

    Tony
  • mshen11
    mshen11 Solar Expert Posts: 185 ✭✭✭✭✭
    Re: Trailer solar application

    someone asked if they had a outback 60 or 80 amp charge controller, would that be as good as a battery monitor?
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Trailer solar application
    mshen11 wrote: »
    someone asked if they had a outback 60 or 80 amp charge controller, would that be as good as a battery monitor?

    No. They are 2 different things. The charge controllers have a pre-programed "profile" they use to recharge a battery,

    Monitors actually measure what goes in & out (via a meter shunt) of the battery.
    [ yesterday 235 amps went out, 85 amps back in, still needs more. ]
    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 ,

  • BB.
    BB. Super Moderators, Administrators Posts: 33,404 admin
    Re: Trailer solar application

    A battery monitor is basically a "fuel tank gauge" for your batteries. Very cool--and they have other functions too.

    Basically Amp*Hour (10 amps * 2 hours = 20 Amp*Hour used) or Watt*Hours (100 watts * 3 hours = 300 Watt*Hours used).

    Highly recommended to help prevent premature battery death--if you can justify the costs ($150-$300 or so). Pretty much required if you have sealed batteries (AGM, Gel/etc.) where you cannot use a hydrometer.

    Part of the confusion may be is because a few solar charge controllers (like Outback) have a battery monitor option, or may have a battery monitor integrated (Apollo) into the controller itself.

    A "standard" charge controller does not have the ability to perform as a battery monitor. They estimate battery state of charge based on voltage and how much current it going into the battery.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mshen11
    mshen11 Solar Expert Posts: 185 ✭✭✭✭✭
    Re: Trailer solar application

    i was told on another solar forum, there is no true way of telling how much is left in a battery (like fuel guage), and the only way is to discharge it fully and perform tests with known load and a timer. but when you fully discharge it... you are on "E", you dont need a guage a that! but after you fully charge again, you would know how many amp hrs the battery truly is, and start calculating how much load you have taken off from that point onward.

    does a battery monitor work similarly (where you you have to fully drain the battery at least once to calculate the true amp-hr [vs the rated amp-hr])

    also how does the monitor isolate individual batteries if you a string of more than 1
  • BB.
    BB. Super Moderators, Administrators Posts: 33,404 admin
    Re: Trailer solar application

    You are correct--batteries age and fail. However, you can estimate the capacity of the battery and the Battery Monitor tells you where you are in relationship to that estimated capacity.

    The idea being that you don't know where you are in battery state of charge without using a hydrometer or measuring the "resting voltage" (or charge/load for a few hours to estimate capacity).

    The battery monitor "totalizes" the Amp*Hours or Watt*Hours into or out of the battery bank and gives you a nice 0-100% reading of battery capacity at anytime... So when your battery is less than 50% State of Charge--you know that you need to stop your loads and/or turn on a genset to get the battery bank recharged to prevent damage/early life failure.

    If you have multiple strings of batteries, you need one battery monitor per string.

    However, if the batteries are matched (model number, lot number, age, same temperature environment) and properly wired, they should all be at the same state of charge. And you would not need a separate battery monitor per paralleled string.

    For diagnosing problems, you could use a DC current clamp type meter to make sure each string is providing its share of current (during heavy charging/loading) to check for problems (corroded cables, bad connections, bad cells, etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mshen11
    mshen11 Solar Expert Posts: 185 ✭✭✭✭✭
    Re: Trailer solar application

    so a battery monitor is not really a "fuel gauge' - aka, you can 'run out of gas' in reality before the guage tells you its empty, right? (in this case, really old/beat up/dying battery)
  • BB.
    BB. Super Moderators, Administrators Posts: 33,404 admin
    Re: Trailer solar application

    Yes, you are correct... But, if I understand the basic battery monitor correctly--they also give you a charging efficiency for the battery.

    As the battery begins to fail, their efficiency falls (good battery, charge voltage is low, discharge voltage is high--as battery ages, it takes a higher voltage to charge the battery and output lower voltage as it is discharged).

    Basically, batteries are pretty near efficient when you measure Amps*Hours... However, when measuring energy P*Hours=V*I*Hours=Watt*Hours--you see the "higher resistance" of the aging battery.

    The idea is that you don't over discharge a good battery and cause it to fail early.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bryanl
    bryanl Solar Expert Posts: 175 ✭✭✭✭✭
    Re: Trailer solar application
    Yes, the battery monitor is the only device out there than can accurately measure and display your battery bank's capacity--because it monitors current in/out just like an odometer on your car or a by-directional fuel flow meter connected to a gas tank (assuming you fill/drain take through the same pipe/meter).
    Electron counters can do well to assess short term efficiencies and their assessment plus battery voltage plus temperature could be used to evaluate a current battery condition.

    The "only" way is to watch the battery behavior and compare that to known characteristics of batteries of the same chemistry and construction. Smartgauge is the only example I know of to do this automatically for bank monitoring. Another possibility would be conductance testing (see the batteryuniversity.com guy for example)

    Then there's the precision vs accuracy problem. Measuring electrical parameters can be done with a precision that far outstrips the accuracy of a battery capacity measure over time.