Location of Controller

bcrippsbcripps Registered Users Posts: 14 ✭✭
This is on a boat. One 50W panel (soon to be two), two 85amp AGM batteries, 10GA wiring with a run of about 20-feet between panel and battery. Choice one: Mount Midnight Brat next to the batteries in a hot engine compartment with limited access, or, Choice two: in the locker at the back of the boat that is close to the panel, and ventilated to the outside. Does it matter?


  • EstragonEstragon Registered Users Posts: 4,451 ✭✭✭✭✭
    Cooler would be better IMHO.  

    A potential issue is voltage drop in the brat->battery wire though, which could make the brat undercharge (thinking battery voltage is higher than it really is).  With 10ga wire, at 15' and ~5a, I'd expect maybe 0.2v drop.  Depending on charging voltage needed by your AGMs, and actual drop, you might be able to set a charge profile to adjust if need be?
    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
  • mcgivormcgivor Solar Expert Posts: 3,274 ✭✭✭✭✭
    The batteries themselves would benefit in a cooler location, every 10°C increase in temperature over 25°C is equivalent to a double cycle, therefore effectively cutting the life in half if maintained at that temperature.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • bcrippsbcripps Registered Users Posts: 14 ✭✭

    Thanks guys. I was looking for a definitive answer, but I guess not :-)

    The Midnight Brat has been happy in the engine compartment for the past year so I guess I'll leave it there. (Not sure about adjusting settings to allow for voltage drop) I have another 50W panel to install and thought this would be a good time to change things around, if necessary. The leads from the two panels will come together in a junction box in the rear (ventilated), locker and I thought moving the Brat to that location might be beneficial, if for no other reason, to be able to see the pretty LEDs. Moving the batteries is not an option. No room back there I'm afraid and I need to keep the weight more central in the boat.

    Again, thanks for the info...


Sign In or Register to comment.