Solar to keep fridge running

BFL, I respectfully disagree. Although the food is only worth $20 retail, its value to an off-grid camping trip is priceless -- if the food spoils, you have to go home or go to town to get groceries. How much is it worth to avoid wasting a day of vacation on a needless shopping trip?

Plus, the thousand dollar capital cost of the panels has to be spread out over many, many loads of groceries. If the food is worth $20, and you sink a thousand dollars into the panels, that works out to fifty nights' worth of groceries. We almost always camp 60 to 90 nights each year. So the cost of the panels is justified in just one year, and of course the panels last longer than a year.

Bottom line -- a properly-sized set of panels is a good investment.

It is all about spending $1,000 to keep $20 worth of food cold for a few days.

And, tuna, I’d say 5 hours was optimistic. I agree with bfl, any dry/boondocking requires a propane fridge 99.9% of the time.

+1 for 600 watts. Maybe a little less if you swap to a lithium battery.

pianotuna wrote:
BFL13,

Most scenarios use 5 hours of production per day, not 7.

Whatever, the OP's plan is probably too optimistic in real life. I have posted more than a few times that if you ever go off- grid, you better have a fridge than can run on propane. Learned that the hard way! BTDT etc. :(

BFL13,

Most scenarios use 5 hours of production per day, not 7.

Not just enough panels....enough battery amp hours...building a system just for the days you are home and not plugged in? Hmmm. Not what I’d do...did. Learn solar basics before buying anything.

If the fridge uses 7 amps DC via inverter, and runs 16 hrs a day being "on" then that is 112 AH from the batteries per 24 hrs.

To keep up with that, with 7 hours of good sunshine per day, you will need a steady 16 amps from the solar for that 7 hours. You would need about 300w of panels lying flat. It doesn't work like that of course because the sun rises and falls during that 7 hours.

So perhaps make it 500w. Two 250w panels and a 20 or 30 amp MPPT controller to run them.

But--since the sun does not shine like that every day, you need enough battery bank to carry you through until the sun shines again. How much battery is that? "It depends."

i have a residential fridge in the safari
with 600+ watts for solar and 665 ampHr battery bank,
5 BIG AGM batteries

just fridge , no lights etc, with good sunny weather
i still loose approx 4-5% per day, sitting still stored, with fridge on

example fully charged 100% at 6PM tonight
tomorrow night at 6pm my meter will indicate 95%, the next day 90% the next 6pm 85% thats approx 35 ampHrs per day loss, that is NOW, more power is produced during the summer

i would suggest a minimum of 400w of solar

how many batteries, what type, what size

the OEM battery setup should be good for at least 24hrs, with out any solar

Hi,

Start with an energy audit.

Here is some reading for you to do: https://freecampsites.net/adding-solar/