Choosing a Propulsion Electric Motor

[deckofficer]

For any that followed me over from the house batteries discussion, here is the reasons why I chose this particular drive motor.
Motor "Motenergy" ME0913 Brushless PMSM BLDC

As you can see at $700 and 30 kW peak, it is the best bang for the buck. Also this type of motor as the best efficiencies and more importantly has enormous regenerative capabilities. Add all that to the fact that I like redundancies, I'll be using the same motor port and starboard plus for the dinghy.

But of course I'm all ears for other's suggestions.

[S/V Antares]

Configuring the big boat should be straight forward but....What dingy are you using? Batteries? Voltage?

[barnakiel]

Cooling.

b.

[deckofficer]

Originally Posted by S/V Antares

Configuring the big boat should be straight forward but....What dingy are you using? Batteries? Voltage?

I have the lower drive of a 50 hp outboard, as you have to size up for the torque of an electric. The dinghy will be one of the air entrapment, minimum wetted surface rigid hull catamaran style. This allows good range at planing speed due to less drag with the reduced cohesion of water drag. Batteries will be LiFePO4, capacity somewhere between 80~160 a/hr, (16) in series for a nominal 96 volts.

Since a 40 hp gas outboard will propel the above dinghy at near 60 mph, I will have to gear up at the motor head to compensate for the 1.85 to 1 reduction in the lower unit. I hate the losses of running both a gear up and a gear down, but don't know how else to do this. On a 50 hp outboard you have a gas engine capable of 6500 rpm vs 5000 rpm of the electric motor and also you are limited on pitch for this lower unit, so you can't just pitch it taller. Of course all available torque at zero rpm will negate any sluggishness on a hole shot.