New to off grid solar help!

solarginger
solarginger Registered Users Posts: 2
I've purchased 8 100watt Monocrystalline solar panels from renogy and I have a renogy 40amp mppt charge controller that can be used to charge 12v or 24v battery banks. I also have a 2500watt TSW inverter and a 4 deepcycle batter bank that I'm going to upgrade from Wal-Mart group 29 deep cycle batteries which are cheap to some 6v Trojan or Duracell golf cart batteries. Now I only have 4 of the panels hooked up cause the mppt C.C. can only utilize 4 or 5 in a 12v system and all 8 or 9 in a 24v system. Now to my question. Is there a way to have my solar panels and charge controller in a 24v configuration and my battery bank and inverter as a 12v system or should buy another 40amp mppt CC at around $220 or buy a whole new $500+ 24v inverter?

Comments

  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    What are the loads you are feeding? that is usually the driver to increase voltage, especially large heavy loads like a water pump, A/C  , heat pump etc...
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • solarginger
    solarginger Registered Users Posts: 2
    edited May 2017 #3
    I don't have any major loads. Largest thing I have in my tiny home is a very small 120v 1300watt all in one washer/dryer combo. Oh and I do have like the smallest window a/c but I normally run it off of a generator.
  • Lumisol
    Lumisol Registered Users Posts: 374 ✭✭✭
    Those washer / fryers are rare indeed.
  • Horsefly
    Horsefly Registered Users Posts: 470 ✭✭✭✭
     :) 
    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 8S (25.6V), 230Ah Eve LiFePO4 battery in a custom insulated and heated case.
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    As westbranch said, the loads are key. The short answer is yes, you can set up a 24v bank and use a 12v inverter, but this is almost certainly a bad idea.

    Since you're already set up for 12v, it probably makes more sense to add the extra charge controller. Before you buy anything else though, I'd suggest thinking the loads through carefully. 1300w at 12v isn't a small load.
    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