Can someone explain the proper way to charge a battery using your auxiliary diesel engine? Seeing diesels like to run at high rpm with a big load on them, what is the proper way to run a diesel if you are at a dock or sailing in a race where it is against the rules to use the engine to turn the prop? My alternator would use about 1/2 hp to charge and the engine is 20 hp. So I am using a small fraction of full load on the engine. Does charging in this way damage the engine?