If two charging systems are both charging a battery bank, there should be no problem. My neighbor bought a Freedom Elite with the Ford chassis and the isolator system was wired incorrectly at the factory. Camping World is notorious for not honoring the warranty and did not in this case either. I have an old Windsport with TWO disconnect switches. One is for the house batteries and one is for the engine battery. Works like a charm and probably cost about $10 to do it like that. I did, however, buy a digital voltage monitor because I didn't like the bar graph system for telling me battery charge condition. I found that when you are plugged in, the system charges to 13.5 volts. When you run the generator, it charges the batteries to 13.5 volts as well (as it should)/ When you run the engine, it charges all the batteries to 14.4 volts which is a proper full charge voltage.