Large Salt water battery ideas and questions

[profitis]

add more @mungo.how much did you add.if you had a milliampmeter attatched you would now see drastic increase of current despite voltage drop.ie.total power density way way up

[tom42]

Wouldn't a shunt-wound or stepper motor be inherently more efficient than a series motor? .Brush life is also a concern

[Paul-R]

... with a generator backup to drive a paddle (stern) wheel

They can be very inefficient.

A propeller specified for the chosen RPM and the speed you will prefer to travel at might well be much better.

[tom42]

What are the waste products of a magnesium/salt/carbon(?)  battery? Isn't hydrogen one of them? How is its explosive nature handled?

[MarkE]

They do emit H2 gas like a lot of batteries do.  It is not a problem unless you are making a big cell and/or the cell is in a highly confined place.    The other waste product is basically milk of magnesia.