Does anyone have any knowledge on electrical systems and alternators for MerCrusier 888 applications? I have a 75' slickcraft and have some questions about battery setups. First is about alternator output. My alternator went out last summer while on a boating trip, by some miracle, the local shop had the alternator in stock for my boat and with a few quick turns of the wrenches the new alternator was in the boat, so I jump started it ran it for a few hours figuring that by driving the boat, I would charge the battery...wrong. I stopped the boat, shut it off, and when I went to start it again, it was still dead. I inquired with so folks and they told me that the alternators in these older applications were designed in a way that they don't actually charge the battery? they just sort of maintain the charge it already has? sounds stange to me, can anyone comment? Secondly, if this is the case, what would be the best way to upgrade to a system that actually charges and while doing so, switch to a dual battery system so that I can run electric downriggers, gps, radio, autopilot, without worrying about being left dead in the water with no charge in the batteries...any help would be appreciated.