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thriftydutch's avatar
thriftydutch
Explorer
Apr 20, 2020

24 volt solar panel

I know absolutely nothing about solar power but would like to install some solar to keep my batteries charged for my electric fridge and not have to worry that the battery is going to get drained. I can buy a 310 watt panel but it is 24 volts.Can i use it for my 12 volt van system.
  • You are hoping to keep the fridge running with solar so you don't have to worry. That depends on the scenario.

    We tried it with the TC we had and 300w of solar flat on roof and with a 3.2 cu ft Igloo 120v fridge. We had four batteries by putting some in the truck box in front of the wheel wells and ran wires into the camper from them. Anyway it was a nail-biter whether it would all keep going four or five days with solar helping out.

    It would not work on battery alone. The fridge ate AH. Some solar was enough to keep the batts over 50% before going home. Sunny every day was good.

    As it turned out, too many times there was not enough solar. We got a propane fridge in there as soon as one showed up in the "used" ads.

    That is why the one 310w panel might not be enough for what you want to do. It all depends on the scenario as usual.

    BTW watch out what size MPPT controller you buy. EG a 20 amp Tracer will be too small. They have watts limits to go with their amps ratings. IMO a 40 amp Tracer would do it for sure and then some to allow for more wattage up there if needed and you can fit it on the roof. (There are portable panel options too that can be added to whatever is on the roof for more total solar.)
  • You have to rely on your controller. Many panels will create higher voltage than 12-13 volts. I see 18-20 volts often on my read out. But the controller will take care of it and not overcharge your batteries.
  • That's a big panel for a van roof. You can perhaps get max wattage by using smaller size (and wattage) panels but more of them.

    You can mount them on higher feet to lie over small roof items like tank vents if need be. Use cardboard mock-ups to try out layouts for what is possible.
  • I have 505 watts of 24 volt panels on the roof with a 30 amp Rouge MPPT controller. The higher voltage panels allow for smaller gauge wire from the panels to the controller.
    As already mentioned, all you need with that panel is a MPPT controller.

    Richard
  • Yes, provided your controller will convert the volts to nominal 12 volts. Your lack of understanding of this basic solar charging concept is disturbing. READ. Read more before you spend any money. Spending any money when you know “absolutely nothing about solar” will get very expensive and make for a crummy solar system.
  • You need a compatible MPPT controller. And depending on the fridge and general conditions you may need a second panel or more.
  • Sure, provided you get a controller that will allow 24v input. Many do, not hard to find.

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