Solar on a Skoolie

Like many here, looking to absorb sunlight to power electric stuff in my bus conversion.
Looks like I need about 2500 watts per day.
Plan to use as an RV, but up to 4 / 5 days off grid at a time.
I have gained some knowledge off of this along with other forums and just looking for some feedback on my system design before purchasing items.

So far, all i have purchased is the batteries.

Any help, greatly appreciated!
thanks, dave






Comments

  • bill von novakbill von novak Solar Expert Posts: 813 ✭✭✭✭
    MambaJack said:
    Like many here, looking to absorb sunlight to power electric stuff in my bus conversion.
    Looks like I need about 2500 watts per day.
    Plan to use as an RV, but up to 4 / 5 days off grid at a time.
    My biggest bit of advice - ensure some way to charge via your alternator.  Either a second alternator, or a 12V/24V converter or something.  It can be a lifesaver (or more accurately a battery saver.)
  • BB.BB. Super Moderators, Administrators Posts: 28,139 admin
    edited October 2 #3
    Dave, welcome to the forum.

    And, roughly where and what seasons will you be camping?

    Will the panels be mounted flat to the roof or tilted to better capture the sun?

    What batteries did you purchase (ah and voltage rating, flood cell lead acid or what)?

    If FLA or other lead acid battery chemistry, you do need to check their present state of charge and get them on a charger (1 daya month minimum for FLA batteries).

    That is 2,500 Watt*hours per day (i.e., 250 Watts x 10 hours per day = 2,500 WH per day.

    Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • PhotowhitPhotowhit Solar Expert Posts: 4,764 ✭✭✭✭
    Might consider a fanless designed charge controller, such as a Morning Star or Schneider. 

    Not a lot of fans of Aims inverters around here, might try Samlex for a quality inexpensive inverter.

    2.5 Kwhs , so looking for a fridge and some other assortments of daily life? Not trying to run an air conditioner?

    Panels are about right for a weekend use situation, Flat mounted(?) won't give ideal charging in general, and you have about a 6% charge rate after discounting for Normal operating cell temperatures and flat mounting.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • MambaJackMambaJack Registered Users Posts: 3
    BB. said:
    Dave, welcome to the forum.

    And, roughly where and what seasons will you be camping?

    Will the panels be mounted flat to the roof or tilted to better capture the sun?

    What batteries did you purchase (ah and voltage rating, flood cell lead acid or what)?

    If FLA or other lead acid battery chemistry, you do need to check their present state of charge and get them
    That is 2,500 Watt*hours per day (i.e., 250 Watts x 10 hours per day = 2,500 WH per day.

    Bill
    Thanks!

    I would say say any time of the year would consider camping currently live in southern Missouri.
    May put a wood stove in for winter, still considering.  
    Probably flat on the panels.  I could make them tilt, but so close together, I am afraid one would shade the other.
    Batteries are 6v 235ah fla golf cart batteries that i plan to store in a toolbox mounted down below the bus.

    What does it mean to check their present state of charge?
    Not sure i understand the 250 Watts x 10 hours per day, does that pertain to the batteries or panels?

    Thanks,
    dave








  • MambaJackMambaJack Registered Users Posts: 3
    Photowhit said:
    Might consider a fanless designed charge controller, such as a Morning Star or Schneider. 

    Not a lot of fans of Aims inverters around here, might try Samlex for a quality inexpensive inverter.

    2.5 Kwhs , so looking for a fridge and some other assortments of daily life? Not trying to run an air conditioner?

    Panels are about right for a weekend use situation, Flat mounted(?) won't give ideal charging in general, and you have about a 6% charge rate after discounting for Normal operating cell temperatures and flat mounting.
    Will look into that, what does a fanless design help with? do they just run cooler?

    Will look into Samlex also, trying to find a good inverter/charger without too much investment.

    Yep, standard stuff i recon, Refrigerator, Water Pump, Lights, Phone/Laptop Chargers, Monitor, 12v Fan...... Microwave, Toaster, Coffee Maker, Hair Dryer, Waffle Iron (jk on those last ac burners)

    I may be naive in thinking i can go without some type of air conditioning, but not sure, but yea didn't include that in the est 2.5Kwhs

    I have space for a couple more 300w panels if needed?

    Thanks so much for the help!





  • BB.BB. Super Moderators, Administrators Posts: 28,139 admin
    My comment got a little sliced up...

    Was trying to say that you need to check the resting voltage and specific gravity of your batteries to ensure they are charged while stored (keep them over 75% state of charge when stored, or they will sulfate and die an early death).

    https://www.solar-electric.com/search/?q=hydrometer

    You said in your first post 2,500 can Watts for your load. You later used Watt*hours, which is the proper unit for measuring your loads energy usage over time (1 day here).

    Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • EstragonEstragon Registered Users Posts: 3,006 ✭✭✭✭✭
    The advantage to a fanless design in a mobile application is they're quiet. Not a big deal if it's going to live somewhere fan noise isn't an issue, but coud be if it's going to live in a locker next to your bunk.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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