Electric inboard motor, my journey to find proper motor

Yes, it's why I use No-Ox-Id on every electrical connections.
After removing natural oxide with scotch brite, of course.

 

Auminum cables on a boat are a terrible idea. They are prone to fatigue cracks. Electrolytic corrosion is another drawback. Finally, they have to be of a larger gauge for the same current rating as a copper conductor. Aluminum has 61% of the conductivity of copper.

 

Yes, I know this since I started to play with lithium battery 16 years ago.
BUT, I learn recently that some aluminum grade have huge difference in conductivity. 61% is only for 1100 serie and 6101.
Here some % of conductivity for popular and easily available grade:
-3003-0 = 50%
-3003-H14 = 41%
-5052-H32 = 32%
-6061-T6 = 43%

Those are really important differences

 

That is right, their conductivity is even worse.

 

I've end up to build a dyno in order to test and validate the power capability of the Leaf motor at low voltage (48V-60V).
All detail here: Nissan Leaf motor at 60V, 1/6 the power? https://endless-sphere.com/sphere/threads/nissan-leaf-motor-at-60v-1-6-the-power.128422/

I'm really happy with the results of 10-12 kW at 1000-1100 rpm for my direct drive application.
Only 240-270 phases amps need to reach those results.

Edit: new test reach 14 kW at over 1100 rpm.
With more fine tuning it will probably reach over 15 kW.

 

I love the optimism!
It just feeels soo goood.

 

In fact, at the moment with my dyno, the ME1507 motor (small black one) suffer a lot and cannot generate enough torque to regen strongly (despite 1200 phases amps).
So, the Leaf motor cannot genereate more power.
Connect it to a big prop will resolve this and the max power I've reach on dyno (14 kW at 1100 rpm) can become a 15 kW at slower rpm.

Anyhow our Cat will reach cruising speed with lower power than that. Vicprop calculator give me 6-7 knots with 9-16 kW (from two motors, so 4.5-8kW / motor).

 

Fine tune some parameters and reach 16 kW at 1080 rpm.
That will be simply awesome for our application.