Depending upon how much you used your battery, 100 Watts panel cannot technically charge to 100% in 30 minutes if your battery was at 50%, you would also need a few hours past bulk charging to do that, but it is cool it built it back up to where you needed it to be regardless, especially for a few days trip. Bulk charging is very fast, and it is usually 80-90% capacity, but it can easily take a few hours to get that last 10-20% charge completed. Most battery monitors are not very intelligent, so they indicate 100% at a certain voltage charge, but that is not the entire picture, so it can be deceiving. The practical side of it is if your batteries are charged enough to do what you want them to do, and over 80%, it can work. Batteries might not last as long as it could if it is not charged properly to a true full capacity, but heck unless you are full-time RV'er its not really a big deal. Buy a new battery every couple years and have fun!
I built a 165 Watt system, and it works well. I try and make sure the battery is charged to over 100% actually, these are deep cycle 6V golf cart type batteries designed to take that kind of charge. I use a smart controller and monitor from Bogart engineering (TM2030 and SC2030). The panels are portable and I set them up outside the trailer in the best direction of the sun, hook up the cables, and off they go!