Solar panels and fridge running on 12V

[François P.]

Hi, I am starting to look at flexible solar panel systems to keep our battery charged in situations where AC power is not available. On DC power, we have LED lights, a Fantastic fan and a Norcold DC0040 fridge (2-way 110V/12V). So the question is: can a reasonably low-cost solar panel system provide enough power to keep the battery charged and the fridge running on 12V all the time?

TIA,

Frank

[cpaharley2008]

What is the amp draw of the refer while in 12v mode?

[François P.]

Thetford site says 2.7-1.35 amps.

[François P.]

I should mention this is a compressor fridge.

[cpaharley2008]

you have one of the good ones, so estimating 50% run time 2 a/h over 12 hours will be
24/day. If you get a 50 watt model that should give you approximately 4 a/h for 6 hours or 24/day. So technically you will run out of water before electricity.

[mmeyer]

You need to read the fine print on those published Curves for amp draw. The ones that I reviewed were a family of curves based on ambinet temperature and internal fridge or freezer temperature and were already derated as to run time ("marketing the lower amps" as they pull about 4 or more when running but none when they have reached the thermostat temperature so they give you the average). Granted i did not review the Norcold model but Looked at Engle, ARB and National Luna which were all highly rated as the most efficient and expect it is similar. So you will likely pull at least 48 Ahr/day just for the fridge.
Depending on the size of your Battery Bank you may get a couple of days out of 50 watt panel factoring in the LED lights and the Fan and we haven't even factored in Rainy/Cloudy days or whether the panel is aimed correctly.
I Run 150Watts For my ARB 50 qt. running as a freezer which is the worst situation I can think of at temps up to 85F(30C) during the day With only a Factory Jacket protecting it from the sun for half of the day, and have had no problem with my 2 Trojan 6volts in series. (210 Ahr rated)You could probably get by with 100 Watts. Mount 50 on the Roof and carry the other 50 when you need it.
Michael J

[Ron F]

I have the same DC0040 (12v only, same amp rating) in my EggCamper, LED lighting, and two MaxxFans. I have 185 watts of Solar on the roof and a 150 a/h battery. I set control on the fridge on #2. With outside temperatures mid 70s to mid 80s F and parked in filtered sun, I've timed the fridge cycles. It runs 25% to 30%. The freezer section is not really a freezer, but if you put something in it that's already frozen, it'll stay that way. Other perishables stay nice and cold.

If I had to do the solar over again, I'd keep the big 150 a/h battery, use an MPPT charge controller, and use the flexible panels that Norm (honda03842) installed on the roof of his Scamp. I think these are the panels that he attached to his roof with tape: Sunflex Solar and Alternative/Renewable Energy - About us .

I tried to find his posting of the install, but didn't find it.

Ron

[François P.]

So Ron you can go for a long time with this setup?

François

[cpaharley2008]

Originally Posted by Ron F

I have the same DC0040 (12v only, same amp rating) in my EggCamper, LED lighting, and two MaxxFans. I have 185 watts of Solar on the roof and a 150 a/h battery. I set control on the fridge on #2. With outside temperatures mid 70s to mid 80s F and parked in filtered sun, I've timed the fridge cycles. It runs 25% to 30%. The freezer section is not really a freezer, but if you put something in it that's already frozen, it'll stay that way. Other perishables stay nice and cold.

If I had to do the solar over again, I'd keep the big 150 a/h battery, use an MPPT charge controller, and use the flexible panels that Norm (honda03842) installed on the roof of his Scamp. I think these are the panels that he attached to his roof with tape: Sunflex Solar and Alternative/Renewable Energy - About us .

I tried to find his posting of the install, but didn't find it.

Ron

Here is the posting, it was a thread I started and Norm completed
http://www.fiberglassrv.com/forums/f...all-48167.html

[Raz]

Here's the picture. We were both looking at the same time.

[François P.]

Wow Jim. What a wealth of info in that thread. If not already, this should be a sticker IMHO.

Thanks to all for the advice

François

[Ron F]

Although I haven't tried it, I suspect that I can go for weeks, provided that the sun comes out every three or four days. My battery alone should keep me going for 3 days of frugal electrical use without any sunlight during the day. The key is to assess your daily electrical draw and realistically match your solar to your use.

[Carol H]

Originally Posted by François P.

On DC power, we have LED lights, a Fantastic fan and a Norcold DC0040 fridge (2-way 110V/12V). So the question is: can a reasonably low-cost solar panel system provide enough power to keep the battery charged and the fridge running on 12V all the time?
Frank

Depending on a particular trailers options etc - a couple of items that are 12v power users that I often see left off power need/usage lists are the water pump and the shower pump. I appreciate not everyone has them or actually uses them