Adding an alternator to outboard

[grtlakes]

Hey guys,

I'm looking for guidence through a video or some instructional page on how to add an alternator to a 1984 9.9 hp 2 stroke evinrude.

I just bought a sailboat and the seller told me he has a new alternator that just needs to be installed ...

Any advice, experience, or guidance is appreciated, Thanks!!

 

[Stu Jackson]

WADR, I recommend you forget about doing that. Instead, buy a small or medium size solar panel and a controller for the panel.

The advantage of the solar is that it will always be producing power, even when you're not there and keeping your house bank full which is very good for the life of the lead. The alternators for outboard engines output perhaps 6 amps maximum when the engine is WOT. If you do not run the engine for long, and/or do not go WOT, the input from the alternator is essential negligible. It may well not be worth the effort, even if it costs nothing to do.

Good luck.

 

[Ken Cross]

I never installed one, but had a H 9,9 and it seriously helped keep the battery up when we had motoring days. I also had to keep a float charger on it when it was home on the trailer. Our solar panel was too small to do anything at the time. (5 watt I think.) I think the idea of the solar charger makes good sense assuming you get the appropriate size and a controller for it. The down side is the room it takes on the boat.

Ken

 

[sailaway78]

It is reasonably simple. But you do have to pull the flywheel. Be aware, the alternator on that motor, isn't going to do much. I agree that you would probably be ahead to add a solar panel. If the PO already has the alternator, you might consider that, plus a small solar panel.

 

[Mikem]

Works great on our Cat 25 with one battery. Keeps it topped off while motoring, which with Puget Sound currents, is sometimes extensive. Can run the DS, Chart plot, VHF radio and stereo system.

 

[Johnb]

The outboard may not do all that much to charge the battery but it will provide power for running lights and VHF even if the battery is essentially flat. And it will do it at night when you need the lights and there is no sun. (Duh). And if the motor is hand started that makes it even better.
For that reason alone it has value.

 

[Benny17441]

Those small outboard alternators are designed to run navigation lights in small boats when running at night. Mainly intended for skiffs and small power boats that generally do not carry batteries.