Alternator?

[Blinkin]

1977 Chrysler 75hp outboard motor (model: 757 HC).

Excuse my ignorance of this motor, I recently bought it and it is stored at my brothers so I have really only seen it 3 times and I never think to look at things until I am at home pondering all the things I want and need done to it and the boat.

That aside... I am pretty sure the motor has an alternator, please correct me if I am wrong. If it does, could I use it to charge my troller battery as well as my cranking battery? I don't want to stress it out too much, but you have to admit that would be pretty sweet.

Facts and opinions are openly welcomed....

 

[Frank Acampora]

Re: Alternator?

It has an alternator and theoretically it could charge your trolling battery, but don't expect too much. The alternator only produces about 7-10 amps and was primarily designed to keep the starting battery charged and energize the ignition.

After satisfying the engine demands, there will only be left a trickle charge. So while you could charge the trolling battery, it won't nearly keep up with the draw the trolling motor demands and will take forever to charge with the trolling motor not running. Do the math: Say you have 2 amps available and you want to charge a battery with 200 amp hours---gunna take 100 hours. Even if you double the available amps--still gunna take 50 hours running the big engine--that's a whole weekend.

 

[Blinkin]

Re: Alternator?

That is pretty much what I figured I just wasn't sure of the alternator rating, heck i wasn't 100% sure it even had one...LOL! I appreciate the info once again.

 

[steelespike]

Re: Alternator?

The output from your "alternator" is just about enough to maintain your
starting battery.Your trolling battery would hardly notice charging it even if alone.It takes roughly 2 hrs charging for each hour of trolling use.
Get yourself a manual and be careful when doing any trouble shooting.
The ignition system can be damaged by improper testing procedures.