"Richard Tanner" <[EMAIL PROTECTED]> wrote: >I am considering fitting a new alternator to my Beta B43 engine, 175 amp in >place of the 95 amp fitted. This is now being fitted by Beta as standard. The >idea being that it should reduce the running time needed to charge the >batteries when I am moored up for a period of time.
A higher-amperage alternator will enable you to charge your battery more quickly, provided you have a regulator smart enough to set the output voltage correctly throughout the charging cycle. Some years ago, I replaced the standard alternator on my propulsion engine with a 100 A 24 V one. I also did something else, though, which I suggest you consider. I replaced the crankshaft pulley with a much larger one, giving a 4:1 ratio between the crankshaft and the alternator. This means that the alternator spins fast enough to give a significant output at just above idle. The engine is rated to 2,500/minute, but that's fine as the alternator is rated to 12,000/minute. Actually, I very seldom rev the engine over about 1,700/minute. To drive the larger alternator, especially at the larger ratio, I use a poly-V belt. These are much more effective than multiple single V belts. Pulleys for them are readily available, as are belts of many lengths. These belts tend not to slip, and last a very long time. They aren't expensive. My current installation normally recharges my battery fully after only an hour or two of cruising. Very worthwhile. Adrian . Adrian Stott 07956-299966
