Hi.<br /> I have a new 2005 (50 hours) 5.0l Mercruiser I/O on a 23' Caravelle WalkAround.<br /><br /> Last night, while watching the fireworks and bass fishing, I drained one of my batteries. I have dual batteries, and usually have it set to BOTH, but when I anchored, I switched it to use only Battery 1, to make sure I don't drain both batteries while running my TV, Lights, etc<br /> When I went to start it, there wasn't enough juice left in battery 1 to start the engine. I switched it to BOTH and it worked fine.<br /> The question:<br /> How long does it take for this engine to recharge a battery? I take many short trips and rarely run at high speed for more than 5 minutes a day. Would it recharge enough just letting the engine idle? How long?<br /><br />thanks<br />Al