Flexible solar panels.
Really good look at troubleshooting a solar power system problem, how it was fixed. Look at the comments. They are often informed and highlight why this problem happened in the first place: too much amperage going through the wire because solar panels connected in parallel. Parallel connection yields high amperage. Series connection yields high voltage. Normally, w/ MPPT charge controller, high voltage is desired. But this owner didn't want that for some reason I can't recall, but which he states in comments.
As the names suggest Monocrystalline and Polycrystalline are both types of solar cells that are made from crystalline silicon. Almost all quotes you will get when considering buying solar panels for your home will use crystalline solar panels.
In my humble opinion the choice between monocrystalline and polycrystalline solar panels is not something that you should lose too much sleep over when looking to purchase solar panels for your home. It is more important that you choose a good brand of solar panels. A good brand of solar panels is from a company that invests heavily in the quality of their manufacturing process and invests heavily in their reputation. Click here to see reviews of different solar panels to find the best solar panels.
Wow, $1000 to mount your panels is outrageous. It is about a 1-2 hour job and the hardware for the mount should cost no more than $20. I do have a couple of suggestions.
Dump the PWM controller and replace it with an MPPT controller. MPPT controllers operate quite differently than PWM controllers and will give you as much as 35% moreoutput from your panels. A 20 amp MPPT controller should be adequate for your 200 watts of solar panels, although for very little more money you can buy a 30 amp controller that wil allow you to add a third 100 watt panel in the future..
If you buy an MPPT controller, connect the two panels in series, not parallel. That will let your system put out usable power for more hours each day and in lower light (i.e., overcast or partial sun).
Permanently connect the second battery in parallel with your house battery. That way you will always charge both batteries and will have more power available at night. Also, if you use both batteries together the pair will not be drawn down as far at night and you will get better life out of the batteries.
Finally, get rid of the solenoid between the vehicle and house batteries and replace it with a battery combiner relay. That sort of setup will automatically connect your house battery(s) with the vehicle battery when the engine is running and then automatically separate the batteries when you turn the engine off.
Really good overview of mistakes these guys made in setting up their RV solar system. So glad they shared this.