Electric harbors are coming.

Oct 1, 2007
1,856
Boston Whaler Super Sport Pt. Judith
Torqueedo test drive: I've never touched one and there were no instructions in the bag so I didn't know what to expect.

It's an easily managed package though and the bags are well made. The engine bag is about the size of a tennis racket bag but weighs more. The battery bag is quite small and not as heavy as I expected.
View attachment 168653

I flopped the West Marine 260(or something) into the water. I was amazed at the weight capacity on the transom. Over a 1,000 pounds. But I couldn't, unless you were hauling bricks, how you get the weight in. With two people in it I couldn't imagine much room for gear. But it is a nice small RIB for 2 people and a little gear. But sorry, this is about the Torqueedo.

With no instructions (I'm sure they're online but I didn't have time) I went at it blind. The motor is nicely buckled in the case. Solid piece, heavier than I expected, it's still a very light engine to lift and put on the transom from the dock.

Next the handle piece is very intuitive, the big joints obvious and easy to lock. The batter next, same thing after I realized there was pin that had to be pulled. Pin back in - check.

It clearly states to connect engine cable first / last.

Then I was stumped! How do you turn it on? I assumed the plastic piece on a lanyard was the key, but there was another red piece that looked like it went in something. Clearly I was showing my lack of tech evolution (I still drive vehicles with crank up windows,...).

So phone google, PDF, in German,...arggg, scroll scroll scroll. There it is, simple the key is a magnet and the symbol is right on the housing. Click, it sticks and that's all you do. I gave the throttle a little twist and sure enough, thrust.

Thrust it's got. The chubby little RIB feels like it's being pushed by more than 2 or 3 HP motor. With me alone sitting on the one thwart in the RIB, the little screen was showing 5mph. If Leaned forward a bit it went up to 5.3,5.4 mph. Clearly not planing but impressive power to me.
View attachment 168654

It made alittle more noise than I expected but after throttling back, I realized it was mostly the ruckus of the wake and RIB. You could have a normal conversation at full throttle.

More at a 'cruise' speed, 3.5 mph it's very quiet and was pleasant to cruise around the small pond it's on. I snuck up on a loon and her chick. I was quite close and they still didn't dive. But I peeled off and left them alone.
View attachment 168656

I'm impressed with how well it seems to be designed and built. The meter was telling me state of charge, even watts used. With that it doesn't take long for any user of EV gear to conserve their energy.

All in all, this is a nice compact dinghy motor. Easy package to carry along with gear for many coastal sailors that drive to their boat for a few days of sailing.

Not trading in my oars yet though,.... :)
Nice article Tom. I see you adding to your portfolio as a maritime writer. Equipment evaluation, a nice sideline :) On the tech side, how is the battery charged? Do you see the technology of the battery? Is is Lithium-Ion?
Thanks
Rick
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
@TomY , is that thick cable the battery connection? What's the port with the cap off on the port side?

I would have thought they'd have devise some kind of contacts like the cordless power tools rather than a cable.

Thanks,

jv
 
Oct 19, 2017
7,733
O'Day 19 Littleton, NH
Not even close. The diesel could drive them at 20 kt. or better; the electric motor at 6 kt. or less. This is why the submarine snorkel was invented.
My impressions of early electric submarine drives comes from a tour of the USS Torsk in Baltimore, Md.

Another aspect to consider about electric motors is the advantages of mult-phase AC vs DC motors. It is my understanding that AC motors have the potential for equal to greater efficiency because of their ability to run from current in both directions. Being multi-phasial, one lead can feed another to impart a greater portion of the energy taken from the electron stream. They loose some efficiency to their induction coils to generate the magnetic field, but are less expensive to build than a DC motor with permanent magnets powerful enough for transportation.
DC motors are simpler and may have better acceleration torque and greater operating range, but energy out is energy lost unless there's a way to refeed it back into the circuit. I believe the current state of technology makes them a bit more efficient than AC induction motors.
Maybe batteries will never get to the energy storage density of chemical combustion, but with 80% - 95% motor efficiency, they are getting better and better at competing against gasoline and diesel combustion engines for power output per storage source capacity.

Here's a quote with an explanation of some basic differences in the three primary types of electric motors,
"Because the amount of energy that can be stored chemically (i.e. in a battery) is quite limited, nearly all electric vehicles are designed with efficiency in mind. Most transit application traction motors for automotive applications range between 60kW and 300kW peak power. Ohms law indicates that power losses in cabling, motor windings, and battery interconnects is P=I2R. Thus reducing current in half reduces resistive losses by 4x. As a result most automotive applications run at a nominal DC link voltage between 288 and 360Vnom (there are other reasons for this selection of voltage, too, but let's focus on losses). Supply voltage is relevant in this discussion, as certain motors, like Brush DC, have practical upper limits on supply voltage due to commutator arcing.

Ignoring more exotic motor technologies like switched/variable reluctance, there are three primary categories of electric motors used in automotive applications:

Brush DC motor: mechanically commutated, only a simple DC 'chopper' is required to control torque. While Brush DC motors can have permanent magnets, the size of the magnets for traction applications makes them cost-prohibitive. As a result, most DC traction motors are series- or shunt-wound. In such a configuration, there are windings on both stator and rotor.

Brushless DC motor (BLDC): electronically commutated by inverter, permanent magnets on rotor, windings on stator.

Induction motor: electronically commutated by inverter, induction rotor, windings on stator.

Following are some brash generalizations regarding tradeoffs between the three motor technologies. There are plenty of point examples that will defy these parameters; my goal is only to share what I would consider nominal values for this type of application.

- Efficiency:
Brush DC: Motor:~80%, DC controller: ~94% (passive flyback), NET=75%
BLDC: ~93%, inverter: ~97% (synchronous flyback or hysteretic control), NET=90%
Induction: ~91%: inverter: 97% (synchronous flyback or hysteretic control), NET=88%

- Wear/Service:
Brush DC: Brushes subject to wear; require periodic replacement. Bearings.
BLDC: Bearings (lifetime)
Induction: Bearings (lifetime)

- Specific cost (cost per kW), including inverter
Brush DC: Low - motor and controller are generally inexpensive
BLDC: High - high power permanent magnets are very expensive
Induction: Moderate - inverters add cost, but motor is cheap

- Heat rejection
Brush DC: Windings on rotor make heat removal from both rotor and commutator challenging with high power motors.
BLDC: Windings on stator make heat rejection straightforward. Magnets on rotor have low-moderate eddy current-induced heating
Induction: Windings on stator make stator heat rejection straightforward. Induced currents in rotor can require oil cooling in high power applications (in and out via shaft, not splashed).

- Torque/speed behavior
Brush DC: Theoretically infinite zero speed torque, torque drops with increasing speed. Brush DC automotive applications generally require 3-4 gear ratios to span the full automotive range of grade and top speed. I drove a 24kW DC motor-powered EV for a number of years that could light the tires up from a standstill (but struggled to get to 65 MPH).
BLDC: Constant torque up to base speed, constant power up to max speed. Automotive applications are viable with a single ratio gearbox.
Induction: Constant torque up to base speed, constant power up to max speed. Automotive applications are viable with a single ratio gearbox. Can take hundreds of ms for torque to build after application of current

- Miscellaneous:
Brush DC: At high voltages, commutator arcing can be problematic. Brush DC motors are canonically used in golf cart and forklift (24V or 48V) applications, though newer models are induction due to improved efficiency. Regnerative braking is tricky and requires a more complex speed controller.
BLDC: Magnet cost and assembly challenges (the magnets are VERY powerful) make BLDC motors viable for lower power applications (like the two Prius motor/generators). Regnerative braking comes essentially for free.
Induction: The motor is relatively cheap to make, and power electronics for automotive applications have come down in price significantly over the past 20 years. Regnerative braking comes essentially for free.

Again, this is only a very top-level summary of some of the primary design drivers for motor selection. I've intentionally omitted specific power and specific torque, as those tend to vary much more with the actual implementation."
Taken from an answer to the question, "why they use an AC motor which requires a power inverter instead of DC which may be powered directly from their DC battery?"
On Why does a Tesla car use an AC motor instead of a DC one?

Diesel engines, to compare, are reported to be in the range of 45% efficient.
Here's a quote, "Modern compression-ignition diesel engines dominate the commercial trucking industry with efficient engines that convert about 43%–44% of fuel energy into engine work, based on 2013–2014 certified engines."
This from: The International Council's on Clean Transportation

-Will (Dragonfly)
 

TomY

Alden Forum Moderator
Jun 22, 2004
2,758
Alden 38' Challenger yawl Rockport Harbor
Nice article Tom. I see you adding to your portfolio as a maritime writer. Equipment evaluation, a nice sideline :) On the tech side, how is the battery charged? Do you see the technology of the battery? Is is Lithium-Ion?
Thanks
Rick
Li-ion battery. The small electrical port is the charger which is a standard 120AC charger.
 

TomY

Alden Forum Moderator
Jun 22, 2004
2,758
Alden 38' Challenger yawl Rockport Harbor
@TomY , is that thick cable the battery connection? What's the port with the cap off on the port side?

I would have thought they'd have devise some kind of contacts like the cordless power tools rather than a cable.

Thanks,

jv
Yes and the port small is the charger connection (which I see has a waterproof cap which should be installed.)
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
What's a "standard 120AC charger?" You mean the AC charger supplied by Torqeedo?
 
  • Like
Likes: TomY
Jun 14, 2010
2,081
Robertson & Caine 2017 Leopard 40 CT
I got to use the Torqeedo today and tonight. It’s a very different experience from any other dinghy motor I’ve used. We only heard the gurgling of water, no engine noise. ;). It’s nearly silent. We could have a conversation.
Yes, there is some range anxiety, even with the LCD display showing projections of remaining range. One must slow down if you want to go far. Maybe there is something Zen about that?.... something to think about. ;)
At the dinghy dock, twist one way for forward, the other way for reverse. No awkward reaching for shift lever.
Push a button to start, no recoil starter.
Plugged it in to 12v outlet on boat. It draws about 4A.
The Admiral loves this motor.
 
  • Like
Likes: TomY

TomY

Alden Forum Moderator
Jun 22, 2004
2,758
Alden 38' Challenger yawl Rockport Harbor
I got to use the Torqeedo today and tonight. It’s a very different experience from any other dinghy motor I’ve used. We only heard the gurgling of water, no engine noise. ;). It’s nearly silent. We could have a conversation.
Yes, there is some range anxiety, even with the LCD display showing projections of remaining range. One must slow down if you want to go far. Maybe there is something Zen about that?.... something to think about. ;)
At the dinghy dock, twist one way for forward, the other way for reverse. No awkward reaching for shift lever.
Push a button to start, no recoil starter.
Plugged it in to 12v outlet on boat. It draws about 4A.
The Admiral loves this motor.
I took a ride with the one of the owners with the one I tested. She loved it. I must have made a mistake or the battery cable didn't make contact as I got an error. Never having read the instructions, I just intuitively held the start button down for about 5 secs. Sure enough, it shut off just like most electronics. On restart, all was clear.

If you are very gentle with the throttle, you can achieve minute RPM's. This made it easy and fun bringing the dinghy close to the dock and twisting it to fit perfectly in the space.

On the noise, I realized after I said it made more than I expecpected, I'm the wrong person to judge dinghy propulsion noise. :) The noise is all the water flow and ruckus from the dinghy. The motor after all is electric and 2' under water, with no exhaust.

One question: Not having read the pdf yet, what happens when you contact something with the prop? Is there a shear pin?
 
Jun 14, 2010
2,081
Robertson & Caine 2017 Leopard 40 CT
Also, the charge draw from 12v tapers down from 4A to near zero once the Torqeedo battery is 100%. So I think I can leave it plugged in when I leave the boat and let the boat's solar keep everything going.
 
Last edited:
  • Like
Likes: Will Gilmore

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
One great advantage that I haven't heard anyone mention is that a Torqeedo just starts! No priming, no choke, no dozens of pulls when something's not right.
 
  • Like
Likes: FastOlson
Jun 14, 2010
2,081
Robertson & Caine 2017 Leopard 40 CT
As these are clients, I suspect I'll be visiting that shear pin....
Mine came with an extra pin (maybe 2, I need to look). It also came with about 6 printed manuals, each with two languages. If you find the manual you might find the spare pin. :)
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Also, the charge draw from 12v tapers down from 4A to near zero once the Torqeedo battery is 100%. So I think I can leave it plugged in when I leave the boat and let the boat's solar keep everything going.
That's great, as long as you don't need the dinghy to get to the boat! :)