Solar Setup in Van

[jimindenver]

My tank is relatively small, about 2.7 gal. ( im not sure how that translates into LBS ? )

That is a small tank, then again everything in a Class B is smaller. You may or may not need to augment it's systems for longer term dry camping. in any event the fridge wont use enough propane to impact your cooking. Could it be possible to replace the tank with larger?

We started out using a cargo van with a futon inside and boat on top. Water was the biggest thing we dealt with, still is with the 25 ft trailer.

[jony101]

Like you i do have a solar panel on my van and have ran a fridge (12 volt edgestar fp430) , i ran it off solar 24/7 for almost a year. i ran it with a 120 watt panel and a 75 ah agm battery, but for me it was the bare minimum needed if you have excellent sun. One or 2 cloudy days and battery would not be able to keep up with the fridge.

For low voltage panel mppt will be of no use. I tried using an mppt controller with my 21 volt 120 watt panel but didnt get any extra amps out of it. With the 120 watt kycora panel, I never got more than 7 amps, it usually average 6 amps when the sun was overhead and in perfect weather. Eventually I upgraded to a 240 watt panel (about 30 volts) and a 145 ah battery, that works better if you have a fridge, it gives you more cloudy days that you can operate under. Also mppt works on this panel. On this 240 watt panel I get (pwm = 7 amps) or (mppt = 12 amps). I eventually got rid of the fridge but it ran without problems with the larger battery/panel, from my own experience you just need one large panel,mppt and a somewhat large 12 volt battery (at least 100 ah). My house battery is 100 percent solar, no isolator or shorepower, with 240 watts the battery is almost always on float mode by noon.

Using a dc wattmeter I connected it to the fridge and measured how many amps total it consumed over 24 hours when set to 40 degrees, it consumed about 26 amps total. Even though the fridge peaks at about 6 amps the constant current was about 4 amps for maybe 15 minutes at a time.

For meter get a dc 90 volt 30 amp combo meter ( you find on ebay) and connect it between your solar charge controller and the battery. Its what I have, it has large leds you can read from a distance and tells you the battery voltage and the amps going in. Mine is always connected and at night I can see the battery status. they cost about 20 dollars. You can also use a dc wattmeter (about 15 dollars) between the charge controller and battery, but it has a smaller lcd screen but just as effective and can measure watts, peak amps etc. Both of these work great if you get a charge controller that has no numerical readout. Being able to tell to tell what your battery actual voltage is more accurate than using a red/green light gauge.
For a panel that small a wincong 20 dollar 20 amp pwm controller will work. Its what i use with both my 120 watt and 240 watt panel, it worked 24/7 for over a year before i upgraded to mppt. The above LED meter is what i used with the wincong and still use with my ecoworthy mppt controller which has its own built-in lcd.