Solar Battery Maintainer Options

[newRVer]

I went over to the storage yard the other day and my coach batteries on my 3011 where low and right at 12V. Since I will be taking the RV for a drive a once or twice a month, I don't want to take the batteries out and place them on a trickle charger for the winter. This led me to start looking at some solar options to keep the batteries topped off and offset some of the parasitic draws in my unit. I started looking at Zamp solar options such as their battery maintainer, Zamp Kicker Solar Battery Maintainer - Zamp Solar but I'm not sure how well these work. Additionally, I will probably be looking at buying some portable panels that could connect into the Zamp connector on the side later this summer. I prefer not to mount large permanent panels on the roof since I already travel at close to the maximum weight as it is. Anyone else doing this or have some experience on how well this works?

[newRVer]

After a little more research, I'm seriously thinking of putting a flexible 100W panel on the roof, mostly for battery maintenance (https://youtu.be/FNPVue6SzdI) but probably going to do so using tape instead of screws. (https://youtu.be/6XSux3Wdghg)
The flexible panel will not add much weight since it is only 3 pounds itself and with the cable and solar controller should not be more than 10 pounds in total.

This will help resolve the battery issues while in storage since I have it stored outside in a good sunlight position and even at low sun angles the larger panel should maintain the batteries even with the parasitic draws. Additionally since we will be connecting to shore power most of the time, I will also be looking at using the Zamp port to connect up another 100-200W of portable panels so that I may not have to run the generator at tailgates or NASCAR events unless we need the AC or Microwave. Then I can store the flexible panels in my toad while traveling so it does not add weight to the RV. Now, I just need to figure out the wiring scheme and cost.