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spanky23's avatar
spanky23
Explorer
Jul 11, 2016

Solar panels on a class C

Ok Iam new here but I have camped most of my life.I just bought a used 1989 Togoa Arrow.It had a deep cycle batter that is charged by the alternater.My question is this,if I add say a 120V solar paniel can I just go from the controller to the converter and still use the one under the hood.
  • Just to be clear
    Battery amp hours and panel watts are not the same thing
    A 100w panel will supply about 5 amps charge in full sun or about 25 amp hrs per day charge
    3 grp27 batteries will give you approx 150 AmpHrs usable power bring the batteries to 50 percent state of charge
    It will take over 30 hours of full sun to recharge those batteries to full
    It's how much power you use per day versus how much the solar panel can put back, most likely operating at a deficet each day, until the batteries get too low, should be OK for a long weekend, but not for a two weak trip
  • Thank all of you for the help.I will be the only one in camper,so my plan is to at lease have 2 bat.in a storage area on the side and the one under the hood.I would like to see about 150-200 amp hours to be safe.I think i can do this with this with a 100Wt.panel,is my plan good to go or do I need to think it over more.
  • Solar panels are typically rated in watts. Also they ahve a 12 volt "Nominal" output, that is actually 21 volts with nothing hooked up to it, and in full sun, while they drop to about 14 volts under full load (that is connected to a battery).

    I would be looking for a 100 - 150 watt solar panel (larger size is difficult to find a location to mount it on the roof).

    PWM Controller, much less expensive than the MPPT type, you can get a PWM 30 amp controller for about $20 - $25. MPPT in the 30 amp range cost well over $150, and IMHO not worth the extra 1 amp you might get when the battery is almost fully charged.

    Cut some 2" angle aluminum to 6" long to make roof mounts.

    Yes you can connect the solar panel to the single battery under the hood for coach battery. It will greatly extend the life of that battery. You might want to consider an additional battery, but by having a solar panel, it will mean that you will not use any power from the battery during the day, only at night, and it should recharge fairly quickly during the day.

    Good luck,

    Fred.
  • spanky23 wrote:
    Ok Iam new here but I have camped most of my life.I just bought a used 1989 Togoa Arrow.It had a deep cycle batter that is charged by the alternater.My question is this,if I add say a 120V solar paniel can I just go from the controller to the converter and still use the one under the hood.


    The standard practice for solar installations is to run the panel output to a solar charge controller, which in turn is connected DIRECTLY to your battery. This will have no negative effect in regards to anything else that may be charging your battery.

    I do not understand your meaning in regard to getting a " 120 volt " solar panel. Normal output for your needs would utilize a panel putting out 18 - 22 volts into the charge controller.
  • Do you mean?
    Connect the solar controller to the converter wires that run to the battery?
    The answer is yes you can do this
    It is not the most effective charge path, not the best way to connect solar wiring
    But yes you can do this
    Sometimes expediency take precedence over the best way to do something
    You can always change it at a later date if you decide you want too

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