[JPBeauchemin]

Hello. Can anyone tell me if this would work. I have for auxiliary power on my sailboat 2 x 24volt (1200 watt) electric drives. Each is powered by 2 x 100 a/h batteries in series (so 4 batteries in total). 90% of the time this works perfectly for me. It's just to get in and out of marinas etc. However I would love to be able to run my electric motors for longer trips where I can't sail (canals etc). I found a 48volt generator that produces 3000 watts. And I was wondering if I connect the generator in series across all 4 batteries (48vdc) and then just attach the motors across just 2 of the batteries for 24 volts. Would that work. I attached a drawing that I did quickly to show what I mean. Thank you

 

[joed]

In theory it should work.
How do you currently recharge the batteries? I will assume a line power charger. Why not a regular 120 generator and plug in the charger? 120 volt genny will likely be easier to find.

 

[Oso954]

If that generator isn’t Marine rated, you can’t install it permanently. And it should never be operated in cabin/below decks.

IMO, you would be better off with a small long shaft outboard mounted a stern bracket. It should be far more efficient.
In your sketch the gas turns an engine, which spins a generator, power into batteries, power out to electric motors. Each of those steps has an energy loss to it.

Also, if you run those batteries down before you fire the generator, you will find that you won’t have full power on the motors. That batteries will be drawing a lot of that 3000w for charging, so you aren’t going to have 2400w for the 2 motors.

With the outboard, full propulsion power is available as long as it is running.
That may be critical in an emergency or unusual circumstances.

 

[JPBeauchemin]

In theory it should work.
How do you currently recharge the batteries? I will assume a line power charger. Why not a regular 120 generator and plug in the charger? 120 volt genny will likely be easier to find.

Currently I mostly just use the motors for 5 or 10 minutes a trip (sailboat) and I have solar panels that gives them enough charge for that. And your right 120 volt ones are easier to find but I can get this one for nearly free.