I want to run this fridge on batteries (charged by solar)

K1ngN0thingK1ngN0thing Solar Expert Posts: 27
Looking at http://www.walmart.com/ip/Igloo-3.2-...eezer/15162473 for my truck camper. How can I tell how much power it draws?

The batteries will be inside so I assume I should go with AGM if they're not vented. How many would I need to run this thing 24/7?


  • jonrjonr Solar Expert Posts: 1,386 ✭✭✭✭
    I would guess an average of .56 kwh per day although I see that it has a review that measured more than 3x that. I expect it will have a large startup load (that you can measure with the right meter). Maybe 1000 watts.

    I am available for custom hardware/firmware development

  • PhotowhitPhotowhit Solar Expert Posts: 5,658 ✭✭✭✭✭
    Jonr has done the math 206 Kwh's a year over 365 days would be 206/365= .56kwh, but that's based on an ambient temperature of 72 degrees (I think, might be 75-6) so summer run times and even times parked in the sun other times of year will drive your inside temps up to 100+ so you might well have double or more energy draw. If you use 1kwh a day(which might still be low, but you will have more sun in the summer) and a reserve of 1 day for a single cloudy day, drawing down to 50% capacity figure 4-5 kwh of storage, figure 400 amp hours at 12 volts... Just a very roughed out guess. Still doesn't cover where your parked, Arizona in the summer sun and you might well be short, Washington state with days of drizzle on end and you might be short. Be sure to wire it in to charge off the alternator for those odd situations.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • K1ngN0thingK1ngN0thing Solar Expert Posts: 27
    I'm on the East Coast. Even this fridge sounds too energy intensive. I guess I should go for something a little smaller. What are you all using?

    Why does http://www.walmart.com/ip/Haier-1.7-...Black/35032711 use more energy than the above? Is it because the above has separate compartments for the freeze and fridge so the freezer has to work less?
  • K1ngN0thingK1ngN0thing Solar Expert Posts: 27
    I'm just going to spend the extra money on a 12v compressor style. What are the cheapest-but-still-reliable options? Waeco looks good but it's more than I would like to spend if I can help it.
  • SkykoSkyko Solar Expert Posts: 121 ✭✭✭✭✭
    12V isn't magic though. I measured our NovaKool 9 cu-ft fridge to draw about 600whr in a 24 hour period. Of course our 1080 watt system is giving me 60 to 70 watts in foggy drizzle and 220 to 260 watts in cloudy conditions, so 600whr is not a issue.
  • K1ngN0thingK1ngN0thing Solar Expert Posts: 27
    I think I'm just going to rough it with a 12v cooler until I can afford a fridge. I could probably get away with keeping frozen foods at the bottom with something like http://www.amazon.com/Koolatron-P20-Compact-Kooler/dp/B00009PGNS/ref=sr_1_cc_2?s=aps&ie=UTF8&qid=1426302042&sr=1-2-catcorr&keywords=mini+fridge+12v which is supposed to keep it 40 degrees cooler than the surrounding air temp, and if I have the AC going, that'll give me indirect temperature control.
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    I did a lot of research on the 12 volt compressor models a year or so ago. I figured Indel B was a reasonable compromise between average load and cost. I think ARB is considered top-of-the-line. Below is a link to reviews of various models I found.



    http://web.archive.org/web/20120417130738/http://www.equipt1.com/Company%20Product%20Images/Indel%20B/Downloads/Indel%20B%20Travel%20Box%20Test%20and%20Comparison%20Report. pdf
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • K1ngN0thingK1ngN0thing Solar Expert Posts: 27
    I'll keep that in mind for the future. For now, how would I go about connecting that Koolatron to a battery? I'm seeing converters that'll do it but as I understand it I'd be losing a lot of power converting power that was just inverted.
  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    I have had similar Koolatrons in the past and have been disappointed with the amount of power they use for the amount of cool they provide.

    We have a 12 volt Truckfridge (it's an IndelB; uses a 12/24 volt Danfoss compressor), model TF130, 4.2 cu ft. (approx 130 qt / liter) It incl. a small freezer that works, makes ice cubes. But in winter if we allow the trailer interior to get cool to cold it does not run enough to keep things in the freezer frozen solid. We use it in a converted cargo trailer (now travel trailer). Typical summer power use varies from 400 to 600 watt hours per 24 hours depending on the ambient interior trailer temperature. We have some extra side, rear, top, bottom insulation and an extra cooling fan and are using a duct system to use exterior air for cooling the condenser, keeping the heat outside.
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • K1ngN0thingK1ngN0thing Solar Expert Posts: 27
    How much power do they use? Judging by the information posted by other users it seems like it would take about 4 hours for it to drain a battery. If I'm using 2+ batteries with solar, and rig it to turn off for a few hours during the coolest point of the night, will I ever really have to worry about it? More than power consumption I'm concerned about running it so often as it seems to be meant for short trips.

    Ah screw it. I'm just going to wait until I can afford a 12v compressor fridge.
  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    How much power do they use? .

    It has been 20+ years since we owned one. Memory may be a little fuzzy but I believe it was about the size of the present P65, about 30 qts. It used about 60 watts when running and it seemed to run most of the time. Even if it only ran 12 hours a day that is 720 watt hours for a unit that was about 1/4 the size of the TF130 we now have.

    I sold it when I discovered it was a poor performer when we moved to the SW. Maybe in a colder climate it would be better.
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    A PS to the above. I have a friend with a small ARB portable fridge (12 v compressor) . We go on week long and sometimes longer 4x4 trips in AZ and UT. He used the ARB to make ice (water bottles, frozen) to keep the food in our coolers cold. Plus he carried the ice cream and had ice for Scotch on the rocks around the campfire!
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • Alaska ManAlaska Man Solar Expert Posts: 252 ✭✭
    Why not use a propane RV style fridge? The ones I have work great and use very little propane in my opinion.
  • unseenoneunseenone Solar Expert Posts: 61
    I do 12/24dc 120 AC fridge / freezer from 40L to 280L You can do a fridge / freezer combo fairly economically.

    You could expect the power consumption is going to depend on the outside temperature to some degree. Many of them have inferior insulation. It's important to remember to precool them, and open them as infrequently as possible.

    My 40L runs on 2.5Amp @ 12V and would run 15-20 hours a day or less in the Texas heat. The 280L draws 6Amp @ 12V. That's a fairly reasonable amount of power consumption. A good way to evaluate a unit is to put on an analyzer and see how it performs. Attachment not found.

    Once the heat in TX hits, the fridge goes in the back of the truck. I supplement the charge with a 100W panel and a 30A Morningstar controller. That will keep the battery charged and the ham radio operational when the truck sits for a couple of days and is not charging from driving it.

    My issue at home is I don't have a full size solar system, so I want to be able to run at least the fridges and freezers which I can do in less than 500W of solar, with plenty of storage for the times when it's overcast for a week.
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