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thriftydutch's avatar
thriftydutch
Explorer
Jan 13, 2019

Solar panel and fridge

Okay here goes. I have a 12v-120v fridge. It is a Norcold DE 704D model. What I want to know is how much solar do I need to run this fridge. Ask any question you want about the fridge and I will try to give that information. I have 2 12volt house batteries.
I am not concerned about winter time. Just spring, summer and fall when the sun is higher in the sky.
Please leave this in the class B section.

17 Replies

  • Does the fridge work well on the 12 volt setting?

    12 x 4 = 48 watts x 24 hours = 1152 watt-hours.

    1152 watt-hours / 5 = 230 watts of panels. However one needs to be able to recharge the battery bank, too! I'd go with at least 400 watts on a flat fixed installation.

    twin 115 amp-hour batteries would yield about 1300 watt-hours usable.

    That would allow for only one "grey day" before another source of power for the fridge would be needed.
  • I just found this info on the fridge.
    120 volts 0.4 amps
    12 volt 4.0 amps
    The batteries I have are 115 amp hours each.
  • time2roll wrote:
    Manual just says max 15 amp fuse
    I assume this fridge draws 10/12 amps at 12v near continuous.

    The minimum I see is 6 batteries and 600+ watts solar.

    Plan to have a small generator to use as needed. With a generator you can get by with less battery and solar until you see what works.

    This is why most use a propane fridge.


    Read the yachting forums. These 40 year old fridges are thrown overboard and replaced with modern Danfoss compressor, 12V DC fridge/Freezers that are much more reliable and use 1/3 the amps. 200W solar and 2 6V GC2,s are what you would need extra for a modern 12V compressor fridge. For what the OP has, at least 3 times that amount. My 5 years experience with a similar sized 12V fridge as the OP is that 50% cycling was the max for us depending on as many as 6 factors which adds up to around 65AH/day being the highest draw/day.


    Dave
  • Manual just says max 15 amp fuse
    I assume this fridge draws 10/12 amps at 12v near continuous.

    The minimum I see is 6 batteries and 600+ watts solar.

    Plan to have a small generator to use as needed. With a generator you can get by with less battery and solar until you see what works.

    This is why most use a propane fridge.
  • Hi thriftydutch,

    We would need to know the consumption in watts and the duty cycle of the fridge.

    In my case that works out to 5.7 KWH per day. That means I'd need about 1000 watts of solar panels.

    Your fridge is likely to be a LOT more efficient than mine.


    thriftydutch wrote:
    Okay here goes. I have a 12v-120v fridge. It is a Norcold DE 704D model. What I want to know is how much solar do I need to run this fridge. Ask any question you want about the fridge and I will try to give that information. I have 2 12volt house batteries.
    I am not concerned about winter time. Just spring, summer and fall when the sun is higher in the sky.
    Please leave this in the class B section.
  • Since the fridge isn’t the only item drawing 12 volt juice, do an energy survey. Multiply by 1.5. Then we can recommend battery AHs, then solar panels, then controller and lastly wiring.
  • The name plate on the refer should give you all you need to know. Amp/hour rating for each power source is? Multiple that by 24. You have the amps necessary to run it for 24 hours. Amp/hour rating for each battery is? Since you do not want to draw a battery below 50%, half of the battery capacity is? Is that more or less than your refers draw? 125 amp solar panel should be OK for 2-12V batteries. But again, the rating of solar panels is kind of ambigious. That rating is based on full sun and tracking the sun. Since neither of those is really practical you really need to assume less output. Whether a panel can fully charge a battery or not is questionable at best. And based on how discharged the battery is.