If your coach has the stock 100w solar panel like our coach has, it might not be enough to keep the batteries charged. In full sun a 100w panel will make about 5 amps, so that's a 5amp trickle charger that only works when the sun is out (about 5 hrs / day). If you can't keep the coach plugged into shore power all the time, I would watch your battery state of charge like a hawk (like every day) until you get a sense as to how long a charge will last. Batteries will fail you when you need them the most, so check them often.