Switching between alternative power sources

Alan_at_Hahndorf
Alan_at_Hahndorf Registered Users Posts: 2 ✭
in Solar Beginners Corner #1

Although not strictly wind and solar, I'm looking for a 12 volt DC switch that will automatically switch power to an auxiliary battery when the vehicle's engine is turned off and revert back to running the car fridge from the vehicle's alternator, once the vehicle starts operating again.

Is there such an animal and if so, what is it called?

The auxiliary battery is being charged through a 15A DC-DC controller and I want to maximise the recharging of that battery by running the car fridge from the excess current produced by the alternator, when on the move.

Tagged:
· Share on Twitter

Comments

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #2
    It's called a single pole double throw relay, the coil would be powered by an ignition circuit, see link, just substitute 12VDC 
    http://www.electroschematics.com/9598/spdt-relay-switch/
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
    · Share on Twitter
  • Alan_at_Hahndorf
    Alan_at_Hahndorf Registered Users Posts: 2 ✭
    #3

    Dear mcgivor,

    Thank you very much for your answer and for being so prompt.

    Really appreciated.

    Alan.

    · Share on Twitter
  • dennis461
    dennis461 Registered Users Posts: 109 ✭✭✭
    #4
    Describe your setup in more detail.  You may already have the device you need in the vehicle. That is, a vehicle battery supplies power to the 12VDC system (radio, lights, etc.) when engine is not running.  Start the engine, DC voltage climbs above approx. 13VDC, and the battery is no longer supplying power.

    What power source is the controller using (you said not strictly wind or solar).
    Camden County, NJ, USA
    19 SW285 panels
    SE5000 inverter
    grid tied
    · Share on Twitter

Categories