Hi all, I have a 1989 Rinker 230 Festiva with a Mercruiser 350. The problem I'm having is when I start the engine. I've replaced the bad battery and after it's fully charged and I disconnect the charger the boat starts fine. I went out cruising for an hour or so and returned to dock, turning off the engine. I went to start it again and a grinding/spining noise came from the engine. The engine was not turning over and it did not sould like a dead or low battery issue, with the starter just "clicking". I hooked up the 55/10/2 amp charger and set it on the start setting, 55 amp, and the engine started right up. The alternator was replaced last year, prior to me purchasing the boat. When I check to see the voltage on the battery while running, it shows 13 volts. I also checked to see if the volts increase as I increase the RPM, but the volts stay steady at 13. Also, starter solenoid was replaced last year. Is this just a poor/rusting wire connection on the starter that is by-passed when I hook up the 55 amp charger to start it or something else? Thanks in advance for any help!