Same here. It is important to adequately load your generator. Depending on your electrical demands relative to the output of your alternators, you may be better off running the genny only after the batteries have run down a bit.
Let's be careful too to know what adequate loading is. I've heard all these stories about never loading under 50%. Northern Lights, however, states the following: "A generator should never run with less than a 25% load. 35% to 70% is optimal." One needs to check their owners manual and/or with the manufacturer. And don't go to a field representative at a boat show or elsewhere. Get the official recommendation.