I believe that my Johnson 70 has a 3 amp alternator. Is this enough current back into the battery to run a CD player, two speakers, the occasional spotlight, and nav lights?
I think that probably is 6 amp. The nav lights and occasional spotlight are no problem, but the CD player probably is asking too much. In any case, a battery is like a bucket. You only get out of it what you put into it. Your motor only puts in that 6 amps while running at a fairly fast speed. So it you run 1/2 hour but run that CD four hours, obviously you eventually will run the bucket dry.
Thanks for the input, so would carrying a spare battery aboard be a good alternative? I already have another deep cycle dual purpose so I should be in the clear as far as cranking and nav lights go. Also I suppose I should have posted this under electrical.
No, you're fine where you're at. Use one battery for starting and nav lites and the other for all your accesories. You can always charge that one when you get home.
