Originally Posted by kennytheecat
I have been give some 2 solar panels and accesories. I would like to know if they can keep my refrigerator running while dry camping.
Is the refrigerator always "on" or does it turn on and off just to maintain temperature?
I have a laptop as well, could I run that thru the inverter as well?
I am obvoiusly new to the solar panel world and would like to see how well they work next weekend.
Any help would be appreciated.
Here is the info
Siemens SP75 Solar Panels (2 Panels)
Morningstar ProStar 30 Charge Controller
Voltage: 12/24 Auto Switching
Solar: 30 Amps
Load: 30 Amps
ProSine 1800/12 Inverter
DC Input: 12vdc, 180 Amps
AC Output: 120 vac, 60 Hz
1800 Watts, 15 Amps rms continous
2 Coach Batteries, 1 Starter Battery (all 3 are the same)
Battery BCI #: 27DCM
Battery CA @ 32 Degrees F: 770
Battery CCA @ 0 Degrees F: 625
Battery Reserve Capacity: 150
Battery Voltage: 12 v
Norcold Refrigerator N641.3
65W-AC Adapter for a laptop
Input: AC 100-240V~1.5A(1,5A) 50-60Hz
Output: DC 19.5V 3.34A(3,34A)
Kenny, I think you meant 12 or 6 volts for the Siemens panels depending upon how they are wired. That would not be enough to run the refrigerator nor charge the batteries enough to run it.
Two of the Siemens panels would provide a total of 150 watts if the panels could be oriented directly towards the sun and only for that portion of the day when you get full sunlight, maybe 4 to 6 hours in the winter and maybe 8 to 10 hours in the summer. If panels are mounted flat on the roof (mine and most are) you lose an estimated 30% reducing the output to 105 watts. Cloudy days, shade, etc.would further reduce the output. Total output might be 400 to 600 watt-hours in the winter max and 800 to 1000 watt-hours in the Summer max.
Your inverter can handle easily handle the load but it would quickly draw down the batteries since the refrigerator requires 178 watts. If it ran four hours total in a 24 hour period it would draw 712 watt-hours as an example. Certainly it would run more in the summer than the winter but I don't have any idea how to estimate how long it would run under either condition. Note that these calcs don't account for any other 12 volt
electrical demand in the coach at all.
The best thing is to run your 12 volt
loads, lights, fan , furnace and an occasional 120 volt load like a TV or even a microwave (might need more battery capacity) and keep the refrigerator on propane.
BTW, I couldn't find anything on the capacity of your batteries in an amp-hour rating at some load like a 20 hour load. The appear to be automotive batteries or deep cycle batteries which are fine but the capacities they advertise that you noted are more for estimating short term capacity to start a car rather than long term loads in an RV.
Our Airstream has two 80 amp-hour gel cell batteries charged by two 135 watt 12 volt
Kyocera panels for a total of 270 watts optimum; more like 190 watt in the horizontal mounted condition. The system runs the 12 volt appliances and the small inverter for the TV fine but in the winter when we have less sunlight it probably would not have enough capacity to run the furnace reliably if temps were in the low 30s and down into the 20s after two cloudy days in a row.