The "start" rpm is where the alternator starts to put out power. Once you start it, it will then work as any other unit would. It does not need to stay above that rpm, it will charge at idle. All that is required is a blip of the throttle or a fast idle during start up. We use these on a whole fleet of school buses with out problem. Ours are 200 amp and once they start working, it will run every light on a bus with out missing a beat! We check each one during oil changes and checks, I have seen 200 amp units put out 175 amps at idle, and thats 550 rpm on a diesel.
Tun the power wire off the alt. to the amp gauge, then out to the battery. Make it as direct as possible for the best charging. Joe
