2 AWG on wiring.


My system comprises of:

Controller RNG-CTRL-ADV30-LI

Solar panel RNG-160DB-H

Battery RNG-BATT-AGM12-100


I know we should install our solar panel as close to the controller as possible, in my case I have a distance of 13 feet (~4 meters) between the junction and the controller. I have plenty of 2 AWG cable laying on my garage. Would it be any good to use it as illustrated? Or should I just use 10 AWG?

I would still have to use the 10 AWG from the junction to the panels and to connect the controller.

Thank you.


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  • Renato Candongas,

    You certainly want to have the controller closest to the battery. The distance between solar panels and the controller is where you would want to add the distance if you need to make space. 2AWG minimizes the most voltage loss, however the controller can not accept 2AWG. You can certainly use 10AWG since the distance is not too far. 

  • Thank you for the promptness of the reply.

    I have a new doubt now. I want to be able to charge the batteries also using the engines alternator (Its a 2008 E350 Ford V8 5.7 liter) .  I will install an isolator and my plan is to feed the (+) cable straight to the battery and protect them using the circuit breaker bellow, but I've read that I could join the (+) cable coming from the isolator to the one coming from the solar panel and put them together on the Adventurer input terminal, is this true?


  • No, I do not believe it is good to have the regulated alternator voltage as an input to the controller.  Alternator charging should go directly to the battery.

  • Hello Bupkis,

    Any word on those circuit breakers? Are they good or would you recommend another type?

    Here is the diagram of what I am planing, can you give me your input on the AMPs I should buy those breakers?


  • most vehicle charge lines (from vehicle battery to trailer battery are 30 or 40A), the long distance and nature of the vehicle batt being close to the voltage reg limits alternator output. Big wire is good for these long runs!

    fuse/breaker controller to batt @ controller rating, 30A?

    Why 2 breakers between batt and alternator?

    You';; need to add a neg wire or use the chassis from batt to alternator.

  • this is how to wire 2 x 12v is parallel, balanced!


  • >>Why 2 breakers between batt and alternator?<<


    If  I have the above situation and a melt at the short point, and a breaker on only one of the endings, the other end will be unprotected.

    >>You';; need to add a neg wire or use the chassis from batt. to alternator.<<

    Yes, I've just forgot to add it on the drawing  :)

    >>fuse/breaker controller to batt @ controller rating, 30A?<<

    That's my thinking too, but according to the manual it would be (8.38*2)*1.56= 26.1456 so I wonder if I should use a 25A fuse since I will never get the 8.38 Amps on real life.

    Every thing is now connected and on test but now I have another doubt. The Adventurer controller has three battery types on the setting: Sealed, Gel and Flooded. My two batteries are AMG (SKU: RNG-BATT-AGM12-100), which setting should I use?

  • AGM are considered sealed

    10g wire can be fused 30A, wire size is the first consideration then load/charge of equipment.

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  • Renato,

    the 1.56 is a factor of safety and you can actually utilize 1.25. So a 20A fuse would also be fine from solar to the controller. Check the manual for the battery charging table. AGM can not be equalized so we recommend the GEL setting. 

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  • Now I have two different replies for the same question...  According to Bupkis AGM is SEALED and according to you is GEL.  Can we agree on one of these settings?

  • I've just read the quoted section bellow from the Optima website:

    >> If your charger offers different modes, select the correct one for your battery. If you use the gel setting to charge an AGM battery, it won't fully charge and, over time, it could actually damage your AGM battery.<<

    Can I have your input on this, 
    Renogy Support Admin?



    please let us know how a 14.6v 2 hr equal ever 28 days is beyond the charge specs of 14.6-14.8 'cycle use'

    The info is available Renato, the specs link even have stand by use and cycle use graphs of charge time ...

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  • Yes Bupkis, there is a lot of info there, but not all makes sense to me, I'm new in this and trying to learn while doing the project.   :)

    For what I understood charging "cycle use" should be 2.450 per cell (x6 = 14.7) so it still doesn't make it clear (to me) which to use and why.

    On my adventure controller it states:

    Equalization Voltage: Sealed: 14.6 V; Gel: None; Flooded: 14.8 V
    Boost Voltage: Sealed: 14.4 V; Gel: 14.2 V; Flooded: 14.6 V; Lithium: 14.2 V

    And again,  its not clear (to me) which should I use.
    It is one thing to be told "do this" and another to try to understand why.  :)
    Thank you for your info and patience.

  • which better matches the charging profile of you battery's use?

    (cycle use 14.4-14.6) seems SLD is the best match!!!

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