Outboard Generator

[gmerrill]

Will be getting my new eclipse late august early september.  Talked myself out of having 2 batteries and just went with one.  Planning on taking some long trips.  Is an outboard generator effective at keep a battery charge.  Most of my use will be through the use of an autotiller. 
Greg

[captronr]

I am far from an expert, but your question has been asked a lot of times.  Here's my synopsis of an answer:

First, the alternator output of a small outboard is very low (I don't recall the numbers).

Next, that output is only obtained by running the outboard at full throttle, something that few of us will tolerate. Most of us use the motor to get out of the dock/slip, get the sails up, and turn it off. 

To get an accurate answer, you'd need to calculate your electrical load, then figure out what a realistic charging time would be. 

To me, a better approach would be a solar panel.  It could operate full time (well daylight) quietly.  It might put out close to what an alternator would do.

Best wishes,
Ron

[waterwheels]

Although my 2014 Eclipse came with a shore power battery charger, I have found I only use it maybe once or twice a summer. I only have one battery. I use it to charge a small gps, cell phones, run navigation, anchor and cabin lights. I did change my anchor light to LED because of all the lights I figured it would be on the longest.
I have an alternator on my 6 hp Tohatsu which produces 5 amps as I motor in and out of our harbour. This seems to be all kind to keep my battery topped up.
But I agree, it is supply and demand, I am guessing a few lights for a few hours does not take much power.

Don

"Living Water"

[captronr]

Don,

As a side question, I'm guessing there is a cable that come off of the motor that goes to the battery for charging. 

Is it on some kind of disconnect so if you take your motor off, it can easily be disconnected?

Thks.
ron

[waterwheels]

Yes there is a simple male and female plug on the motor which can just be unplugged for removing the motor. I had a marina run the wire to ensure the correct size. I believe we put a small hole in one of the inspection hatches to allow the wire to pass through, then sealed it good. Then it just connects to the battery at the terminals.

I can check for sure next time I'm at the boat.

Don

[captronr]

Thanks Don,

After looking at it some more, I think I'll skip the alternator and come up with a plan B if I need to charge the battery more.   Running only lights, stereo, and later a gps/depthfinder, don't think the battery will run down often.

Ron