Mercury - Quicksilver Alternator High Output Marine Charging Series Corrosion-Resistant Marine Construction 8M6007518. Overview. When you're depending on a Yanmar marine engine, whether you're pushing through a long channel or settling into an evening anchor, there's a certain comfort in knowing your electrical system is steady and strong. A healthy charge keeps the lights bright, the instruments clear, and the essentials ready without hesitation. That quiet confidence isn't something you notice