Problem running small fridge

plowman92
plowman92 Registered Users Posts: 3 ✭
in Off Grid Solar & Battery Systems #1
I live in a van with 2x 100w solar hooked up to 3 12v marine batters and connected to a 2000w pure sign wave interver 
wonder why the small fridge I have keeps drying at night and somethings it just won’t work at all turns off and have to get a new one 
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  • plowman92
    plowman92 Registered Users Posts: 3 ✭
    #2
    Fridges is a Hamilton beach from Walmart 4.2 cu
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  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #3
    What size are the batteries, the Ah rating?  Marine batteries are a compromise not true deep cycle, in order to run a refrigerator a reasonably large capacity is needed, most will use 1-1.5Kw per day, the inverter probably uses ~ 0.5Kw so the battery needs to be able to supply 165Ah, keeping within 50% capacity, a total capacity of 330Ah, that's the refrigerator alone.

    Two 100W panels will at best produce around  750Wh or 0.75Kw over the course of 5 hours angled correctly, so the array is grossly undersized in relationship to loads. The refrigerator has probably depleting the batteries to a point where the start current collapses the battery voltage below what is required for the inverter to operate.

    Refrigeratorsare high demand loads, just because it's small physically has no direct relationship with its consumption. Using a power logging device measure actual useage over the course of a week on grid power, this will provide a baseline from which a solar system can be designed. Without accurate numbers it's extremely difficult to speculate and will almost always end in dissapointment.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
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  • plowman92
    plowman92 Registered Users Posts: 3 ✭
    #4
    The fridge 220kwh and the 3 battery’s are 65aph 
    i always check the controller when the fridge runs are they always green which is odd
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  • NANOcontrol
    NANOcontrol Registered Users Posts: 273 ✭✭✭
    #5
    If your panels are flat, you are down to just 100W. And if your controller has a green light, it is likely PWM.  Now down to 70W.  You probably watched that guy on youtube who says you can run a fridge on a 100W panel. You might have a chance if the panels are doubled most days.

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  • Tecnodave
    Tecnodave Registered Users Posts: 437 ✭✭✭✭
    edited June 2019 #6
    Plowman92,

    You might want to peek at DC powered referigerators, they have come along way in the last few years, I'm using a Grape Solar GS-5 12/24 volt referigerator, it draws 3.4 amps at 12 volts , 1.7 amps at 24 volts,  42 watts maximum draw and uses only 200-250 watt hours a day!  1/4 or less than of the average draw of a inexpensive AC fridge.  This is accomplished with a new compressor design patented by Danfoss which has a permanent  magnet DC motor embedded in the compressor, far more efficient than the best energy star small fridges, plus no inverter idle draw which with an inexpensive  inverter is often more than the fridge total draw.

    Grape Solar has exited the business, but these units are now built into high end over the road big rigs. Peterbuilt, Volvo and others have them in the sleeper cab. 3-5 cu.ft., same compressor. The Danish Danfoss compressor has been cloned by the Chinese company Colku, which is what all 3 of mine uses. I have two Grape Solar GS-5's and a unknown brand 3.4 cu.ft. Unit from a wrecked Peterbilt big rig. ($100 from the boneyard)

    Pricey!!!  But solar requirements are far less, it works out.......Google "DC powered referigerator "  for a show and tell
    I bought my GS-5's from Home Depot Online for $800 or so, each!!!  GS-5's are no longer available

    Google :  Green power innovations......there are two, one a big bucks green contractor in L.A. The one in New Jersey is the one to peek at, many styles of DC referigerator, there are others

    5 years now with DC powered referigerator, I won't go back to AC powered by an inverter!
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
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  • Tecnodave
    Tecnodave Registered Users Posts: 437 ✭✭✭✭
    #7
    I have temporarily ran my GS-5 referigerator on a 100 watt panel and one 100 a.h. 12 volt Battery, it ran fine, no loss of temperature and no dead battery, simple PWM controllers while I was rebuilding my solar system. Some of the smaller units at green energy are rated for 1 100 watt panel and one 100 a.h. Battery, not very likely that anyone can do that with an AC powered fridge running off an inverter. I gotta see that to beleive that, you can see anything you want to see on you tube, you just can't do that
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
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  • Tecnodave
    Tecnodave Registered Users Posts: 437 ✭✭✭✭
    #8
    Grape Solar update.....Grape Solar is back in the DC referigerator business, they have a new product offering, a 3.4 cu.ft. Unit found online by an aquintence for 569$ if I remember the page correctly, I was encouraging a freind to look into DC referigerators and he found this. I will search for that one today and post if I can find it
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
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  • Tecnodave
    Tecnodave Registered Users Posts: 437 ✭✭✭✭
    #9
    OK,  That is bad info. I called Grape Solar, that is a used unit that someone has for sale. They have exited the referigerator business. The search term for that used Grape Solar fridge is Google. "DC powered referigerator". Not found with Yahoo search.
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
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  • KenMorgan
    KenMorgan Registered Users Posts: 92 ✭✭
    #10
    go with the Japanese Engel units (sawafuji) .  they have been in production for over 30 years and are bullet proof... though a little expensive.  I had two in my camper trailer, on used exclusively as a freezer, the other a fridge.  I could run them 24-7 for weeks on end with only 400 watts and never strain the 400 amp battery bank (12 volts)   they can also plug in and use AC power but you lose efficiency  as it goes into a transformer that drops it to 12 VDC.
    70kw LiFePo4 battery bank, 18 JA solar 200 watt panels, 20 sharp 200 watt panels,  morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. 
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  • Tecnodave
    Tecnodave Registered Users Posts: 437 ✭✭✭✭
    #11
    KenMorgan,

    Is that 400 watt figure 400 watt hours per day,  that is about what my two Grape Solar units a day, I have mine configured as a cold box and cool box,  the cold box at 33-35 degrees F for dairy, cold drinks, etc,  and the cool box at 43-45 degrees for vegetables as they do better at this temperature. I have been using these for a it more than 5 years now as I remember.
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
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