Wiring an external generator to '89 omc 5.8L

[bulbec]

Hello all! I want to add a small generator to my boat to keep the two batteries charged. Its 12v system. The generator is 800w 120v and is capable of doing 4A at 12v Where do i connect my generator to? I uploaded a diagram that looks right for my boat. Its '89 omc engine 5.8L. Naturally i would connect the generator directly to the battery using dc terminal on generator. But i assume there should be some kind of overcharge protection circuit on board. Also my boat has 120v power outlets and external dock generator plug (it might be 240v not sure). I don't have a diagram for 120v wiring but it is a 89' Bayliner sierra 2755. Any suggestions?

 

[bruceb58]

When do you need to charge your batteries? When you are anchored?

 

[alldodge]

Hello all! I want to add a small generator to my boat to keep the two batteries charged. Its 12v system. The generator is 800w 120v and is capable of doing 4A at 12v Where do i connect my generator to? I uploaded a diagram that looks right for my boat. Its '89 omc engine 5.8L. Naturally i would connect the generator directly to the battery using dc terminal on generator. But i assume there should be some kind of overcharge protection circuit on board. Also my boat has 120v power outlets and external dock generator plug (it might be 240v not sure). I don't have a diagram for 120v wiring but it is a 89' Bayliner sierra 2755. Any suggestions?

Agree with Bruce fill us in with what your overall plan is. I'll add that most all dockside power outlets are 120V 30AMP. You can find 125/240 50AMP split connectors but there for large boats. My guess is you have the regular 120V 30A connectors as seen below. They do make 120V 20A as well and are all twist lock

 

[roscoe]

Know exactly what equipment you are using would be helpful.

Do you have a generator or an inverter generator?
Will you be using an external battery charger?
If so, what brand and model?

 

[bruceb58]

One more thing before we know what you are doing. Typically if you want to use a cheap 800W generator to charge a battery, you are way better off having it drive an external battery charger. You could easily drive a 20A battery charger off an 800W generator and you will be running the generator for 1/5th the time. Also, I m sure an external battery charger is way better than the charger that comes with a cheap 800W generator.

 

[H20Rat]

What kind of generator? If this is one of those cheap harbor freight 2 strokes... I'd HIGHLY recommend never connecting anything more complex than a light bulb to it. Assuming you can get it running reliably (not easy), the voltage will swing from 70 volts to 170 volts, depending on what the motor feels like doing at that particular time. And it is EXTREMELY noisy, both on electrical and acoustical.

Lastly, 4 amps won't do much to charge 2 batteries. That is barely a float charge, and will take days or weeks to fully recharge a pair of dead batteries.