Community Forums

YodaRules · 06-08-2016, 08:01 AM

Am thinking of adding portable solar to my Class B+ in order to run my 3 way refrigerator when boondocking. As it is now, the refrigerator sensor (and other alarm/sensors) will drain my 1 house battery when not plugged into hookups.

Am new to solar thought -- looking at the Renogy 100W Suitcase for the compact storage ability. Knowing I will need to move the panels around to catch the sun (especially when parked in shady places) am wondering what wiring gauge I would need to extend an additional 20' to the 10' that comes with the system? And how much the additional 20' will decrease the sustained amperage.

As the Suitcase system comes with a 10Amp controller, also thinking of purchasing with the controller then getting a 30Amp in case I want to add another 100W panel (later on) to my setup (if doing so it an easy process). Thoughts?

Any thoughts or suggestions would be most helpful as I love learning through other people.....

Patsy

unw1red · 06-08-2016, 08:19 AM

The most important thing you can do in order to be prepared to size your system right is to know how much power you use currently.

For example

Refrigerator uses 50W and you have a 100W solar panel, then you are gaining 50W per hour more than you are using.

You should plan on having more solar capacity than usage so that you can use your devices while still adding/charging your batteries.

YodaRules · 06-08-2016, 10:00 AM

Quote:

Originally Posted by unw1red

The most important thing you can do in order to be prepared to size your system right is to know how much power you use currently.

Looked at the inside sticker (dometic RM2652) and it reads: 120V 60Hz 2.7 Amp (image attached)

I want to be sure to run the refrigerator, maybe small fan at night and 1 overhead light that is not LED.

Thanks,

Patsy

unw1red · 06-08-2016, 10:08 AM

So that is 324W per hour if the compressor is running. If you assume that the compressor will run half of the time, you would need 162W of solar (solar is not 100% efficient so you would need more than this) just to stay even. 200W of solar should get you to break even.

John Hilley · 06-08-2016, 10:28 AM

If your refrigerator runs on propane, that mode will provide the least drain on the batteries. It will be almost negligible. If it runs on 12 volts DC you need to know current draw. This draw would probably not be continuous, but would be considerable. If it is comparable to the AC it would be about 27 amps. The 100 watt panel will probably maintain the battery in propane mode, but not 12 volt DC or 120 volt AC.

YodaRules · 06-11-2016, 11:57 AM

After mulling it over am thinking of going to 200 watts. Found some good images online and photoshoped them until I got what, I think, is a good and full system for my Class B+ motorhome. Right now there is one 12V battery in the house and if there is room will take that out and add two 6V golf cart batteries.

Looking at my image is there anything else I need to get me started? Plan to keep the panels portable on the ground.

Thanks,

Patsy

YodaRules · 06-19-2016, 12:33 AM

Quote:

Originally Posted by John Hilley

If your refrigerator runs on propane, that mode will provide the least drain on the batteries. It will be almost negligible. If it runs on 12 volts DC you need to know current draw. This draw would probably not be continuous, but would be considerable. If it is comparable to the AC it would be about 27 amps. The 100 watt panel will probably maintain the battery in propane mode, but not 12 volt DC or 120 volt AC.

Still working on this. Pulled the specs on my Refrigerator, it is a 2 way and manual states, "proper operating range is 100-132 volts if drops below 100 watts cooling efficiency will decrease". Information under the AC Components (heating element) are 325W, 44 OHMS, 2.7amps.

Will I need an inverter just to run the refrigerator? Could I run the refrigerator will 300W panels or better to go propane and let the panels pick up the 2.7 healing element?

Sorry, if I sound green........ I am!!!

Patsy

nothermark · 06-19-2016, 02:18 AM

Run the refrigerator on propane! It will be much more efficient and run for a few weeks on a tank.

unw1red · 06-19-2016, 08:17 AM

Assuming your 12V is a 220Ah battery, you have 2640WH (watt hours) of which lead acid is about 50% usable, so now we are down to about 1300WH. The battery could run your 325W fridge for about four hours. The 300W of panels would give you about 4-6 hours of great usage per day on a perfectly clear day. That means that on a perfect solar day you would only use about 25WH from your fridge during peak sun hours. Now you have the ability to run your fridge from battery for up to 8-10 hours during the day or still four hours if no sun.

Propane is the better solution.

Jon Barnes · 06-19-2016, 08:53 AM

Quote:

Originally Posted by YodaRules

After mulling it over am thinking of going to 200 watts. Found some good images online and photoshoped them until I got what, I think, is a good and full system for my Class B+ motorhome. Right now there is one 12V battery in the house and if there is room will take that out and add two 6V golf cart batteries.

Looking at my image is there anything else I need to get me started? Plan to keep the panels portable on the ground.

Thanks,

Patsy

I have a portable 140 watt system from Zamp - works well. However, the panels are large - will storage be an issue with your B-van when considering a 200 watt system will be even larger? My Zamp system takes up a lot of space in the basement of my Class A. Just an observation - not trying to discourage you.

YodaRules · 06-19-2016, 05:00 PM

Quote:

Originally Posted by Jon Barnes

I have a portable 140 watt system from Zamp - works well. However, the panels are large - will storage be an issue with your B-van when considering a 200 watt system will be even larger?

The Renogy 150W panels are 39.5"x39" each and I figured out where to store them. The Solar Cynergy 120W panels are about 46"x 22". But, you are right.... in a small RV it is something to be aware of before buying.

Thanks,

Patsy