First Time, I've Searched and need some advice

System
System Posts: 2,511 admin
in Solar Beginners Corner #1
It is probably in here but I'll ask any way.
I am building a small system for field based camping/work to be used 7 days a week 6 months of the year in Wyoming, Colorado, New Mexico, Arizona, and Texas.
It will be portable, fit in my truck, used for general lighting in wall tent, small electronic charging, and running a laptop 3.5 hours every 7 days at most (a movie or two).
Will use commercial wide angle Christmas lights up to 4 hours a night, (4.8 watts a strand, cheap and portable). I currently have a basic Cobra 400 watt inverter that I have to use due to budget. Will be charging rechargeable double A batteries. Expansion into better lights will be down the road. I would rather have a little more than just enough for expansion so long as I don't kill the battery.

65 watt Kyocera panel with Concorde 42 amp hour battery?
50 watt Kyocera panel with Concorde 34 amp hour batter?
50 or 65 watt BP panel?
Smaller Panel, Larger?
Larger Battery?
Paired with...
Morningstar Sun saver 6 amp
30 feet of 10 AWG panel to controller, for placement options
12 AWG with 8 amp fuse, controller to battery
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Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
    Re: First Time, I've Searched and need some advice

    Welcome to the forum.

    The important thing here is to get a fix on your loads. You need to know not only the Watts but the hours also. Once you've got some sort of workable figure for Watt hours you can calculate a battery size:

    Watt hours / nominal system Voltage = Amp hours used.

    Keep in mind that there will be power loss in any system, including the stand-by consumption of any inverter used. It's best to round your Watt hours up. Once you have the battery size you can determine the panel Wattage and appropriate controller to handle the recharging.

    To look at your suggested choices:

    The 42 Amp hour battery would give you 240 Watt hours at best on a 12 Volt system. Under normal sunlight conditions the 65 Watt panel would work (roughly 8% charge current).
    The 34 Amp hour battery would give you about 180 Watt hours. The 50 Watt would work here, again at just about 8% charge rate.

    Without some hard data on power use, you're in the dark (sorry - couldn't resist :p ).
    You can get a Kill-A-Watt (or similar) meter and measure the actual equipment you tend to use to get some real numbers on probable power consumption. Then you'll be able to size up the system.
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #3
    Re: First Time, I've Searched and need some advice

    some laptop chargers don't like mod-sine (Cobra inverter) output. Maybe look into the SureSine inverter from morningstar. (more efficient than the cobra too)

    Also, the laptop is likely to be a LARGE consumer of power, many need 80W or so, and more when recharging their internal battery. You may need to scale up your PV and main battery, to provide for the laptop and it's hours.
    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 ,

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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #4
    Re: First Time, I've Searched and need some advice

    How much moving around and how often?

    5 states in 6 months, sounds like you'll be doing a good bit of traveling, I'd suggest 2 - 6 volt golf cart batteries ( for 12v x 210 amp hour bank), and a switch to charge off of the vehicle. Most vehichles have 30+ Amp charging systems now, and don't use much particularly during the day. If it's a work truck and you happen to have an "Underhood" welder you likely have a 100 + Amp, and might want to moderate the charging...

    I have charged many laptops off of MSW, perhaps 6 (I'm on a true sine wave past 3 years) and I only had one failure that I suspect the MSW might have contributed, an inverter for the LCD back light. Most of the AC in vehicles is MSW and most charge/run laptops. I personally wouldn't worry too much, though I might disconnect and run off of the battery once charged, and I wouldn't remove the battery which I often do at home, when running off AC.
    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.
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