new generator install question

[cpp]

Finally getting rid of the dreaded Onan MDJE 7.5. It did not have an alternator
or separate starting battery. it used one of the main engine's starting battery for starting the generator. Do I need a separate battery for the generator? If not, do I wire the generator's alternator to the main engine starting battery?

Thanks in advance for any help,
Chris Puryear
1978 37C

 

[Bob Bradley]

I replaced my MDJE about 6 years ago with a 9kw Norpro. I wired it up the way the Onan was - using the main starting batteries for starting the genny. Its never been a problem for me, but I think it would be better to have its own battery, for the rare event that your main batteries went dead. Best way would probably be to use a battery selector switch so you could use either the mains or the genny battery.

 

[SeaEric]

I think it would be better to have its own battery, for the rare event that your main batteries went dead. Best way would probably be to use a battery selector switch so you could use either the mains or the genny battery.

That's what I did. I added a dedicated genset start battery which is charged by the genset only. I added a 1/2/All battery switch so that I could start the gen off the stbd main battery if the gen battery died. The new genset battery is tiny - like the size from a lawn tractor. It was easy to find a spot for it. I just finished my 4th season with the new genset (It's a Beta Marine) and so far she has never failed to start.