Re: Will a 12v Alternator charge a 24v Battery?
Hi Wyomingben, first off, thanks again for the great book about sailing I bought from you on ebay. Regarding the alternator question, a 12 volt alternator doesn't know it's a 12 volt unit. The alternator's output voltage is determined by the regulator circuit which reads the electrical system voltage and allows charging as the system voltage drops below the regulator's designed in voltage setting. For example, when my cars alternator developed an internal problem it went into full tilt output and the system voltage ran at 19.5 volts at an idle from a 12 volt alternator, needless to say it wreaked havoc with the cars electrical system, every idiot light was on and some were flashing, looked like a pin-ball machine. I was able to drive the car by turning on every electrical device and drawing the system voltage down to a reasonable range. You could duplicate the same circuit destruction by disconnecting the battery when the engine is running or by bypassing the alternator's regulator circuit and connecting 12 volts directly to the alternator's field circuit with the engine running, in either case you would see the system voltage soar way above 12 volts. SO, if you could come up with and install a 24 volt regulator after bypassing the alternator's 12 volt regulator circuit (if it's an internal regulator) you might have what you need, however, the alternator's diodes may or may not handle the extra voltage and the alternator's charging output current will be cut in half. Sounds good but I suggest you read JB's idea.
