How important is a motor that has a charging system

justsomeguy · May 9, 2017

You're right, not much use.
It should be able to run your steaming and nav lights if it comes down to battery failure. I look at my tiny alternator system as "gravy"; when motoring, at least I'm not currently in the process of draining the batt.

kloudie1 · May 9, 2017

On a friend's Stiletto catamaran, we converted all lighting to LEDs; the motoring we did with the Yamaha 9.9 and its alternator (10 watts) was sufficient to keep the battery charged.. sorta..
We did not use it for stereo or GPS.. but we did occasionally run autopilot especially while motoring.

Johnb · May 9, 2017

The fact that you can pull start the motor and then power essential navigation lights and depth finder etc makes you proof against a dead battery. For the relatively small extra expense I went with charging capability. You will never regret having it

Gene Neill · May 9, 2017

Depends on what you're doing. If you're just day sailing, it isn't going to be very important. If you're cruising for multiple days, you're going to want all the power you can get, from as many sources as you can get it. Autotillers, GPS's, cell phones, tablets, bluetooth speakers, VHF's ... it adds up fast.

Tom J · May 9, 2017

On my O'Day 23, I didn't have a charging system on the 9.9 Yamaha, so I put a second battery on the O'Day. When the charge got low, I would switch to the second battery, and then take the first battery home to charge it.

John Nantz · May 9, 2017

Gene had a good reply, and it "depends on what you're doing:"

Gene Neill said:
Depends on what you're doing. If you're just day sailing, it isn't going to be very important. If you're cruising for multiple days, you're going to want all the power you can get, from as many sources as you can get it. Autotillers, GPS's, cell phones, tablets, bluetooth speakers, VHF's ... it adds up fast.

What I'd add is, the output voltage of the outboard generator is quite high. I remembered one Mercury 9.9, about 20 years go, that had an output around 16 volts, or maybe more. The running lights on the boat were really bright, even though the lenses were old and quite crazed. I had to bring the boat from the marina where it was launched to a place that was several hours away, and in the dark. I was concerned that the high voltage would burn out a bulb.

Maybe the newer outboards have a different charging system now but before connecting the output to any sensitive electronic items it would be a good idea to investigate what the output is and determine if there should be anything in it's path to regulate it. Maybe a battery is all one would need? Regulator? whatever.

If it were me, with a 22 footer, I'd turn it into a little pocket cruiser and be overnighting on it with some electronic gear, maybe some kind of a cooler, interior lights, anchor light, stuff like that. In that case a little generator with a battery would be handy but I'd still have some solar.

What do you think?

LeslieTroyer · May 9, 2017

I thought it important in 1983 when I had my C22 - thus the honda 9.9 which was the smallest OB at the time with an alternator - probably only need it on one time. Mostly just charged at the dock. Of course the draw on the battery was a lot less then than now... IIRC it was only a 2.2A charger anyway.

les

Johnb · May 12, 2017

the output voltage of the outboard generator is quite high.

Yes if you have no battery and a light load. There is no regulation and just like with the old motorcycles it could be murder on light bulbs without a battery to load it down.

Jacktar · May 12, 2017

The newer tohatsu sail pros (6 hp) come with a alternator and it has a regulator. It will put out around 13.5 volts at around 1/3 to 1/2 throttle, but it is a slow charge rate and you have motor for a while. Beats dead battery on dark night on a lee shore.

Captain Larry-DH · May 13, 2017

Most outboards that have alternators also have elecstart. Easy on your arms and shoulders. The primary purpose of those alternators is to replenish the start battery. If you can run some LED lights, all the better, but there's really not enough power generated to keep up with the loads of even a weekend cruiser with interior lights and typical boat electronics.
However, every thing helps. Better if you can add solar, but shorepower charger might be needed to top off frequently.

Ward H · May 13, 2017

My 9.9 seems to keep my battery topped off. The battery goes in fully charged at launched. Last until September vacation where I top it off with a portable charger.
We are day sailing with GPS and auto pilot two times a week on average.