ePropulsion and Torqeedo experiences

weightless

Super Anarchist
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I can't figure out what causes this when the thrust figures between the motors should be similar.
Many of us have observed that "equivalent" gas motors produce more thrust than electric in the service we put them to. They give better speed, better acceleration, and do a better job of driving into wind and seas. If tests produce results that differ from observations then the tests aren't testing the thing being observed.

 

fastyacht

Super Anarchist
12,928
2,600
Many of us have observed that "equivalent" gas motors produce more thrust than electric in the service we put them to. They give better speed, better acceleration, and do a better job of driving into wind and seas. If tests produce results that differ from observations then the tests aren't testing the thing being observed.


Thanks for the response. That is certainly an interesting experience in regards to the electric's lack of ability to push the boat. Or more importantly, that the gas one did not struggle with thrust either.

I wonder where this discrepancy comes from? You are not the first one that told me about this experience(one of the few with a good explanation though) and I can't figure out what causes this when the thrust figures between the motors should be similar. Not range or peak power that the gas engine wins every time hands down, but actually usuable thrust that should not be higher but in every direct comparison always seems to be.

What I wish for companies using some good standards for comparison instead of leaving the marketing department to being useless.
Or puplish some good depiction of use cases instead of feel good videos...

For me the benefits of going electric(the smell, gas everywhere, somewhat more maintenance. Vibration. Damn the noise and vibration!) do outweigh the drawbacks. But I'm also sharing the boat with family members that are... harder to convince and I am not switching outboards every time I want to go out.

Thanks for sharing your experience in detail. Got a good argument or two and things to look out for from it.
Now to find someone I can pick a motor off of in my area and demonstrate that it works with my boat... I asked a local supplier about this and he just shrugged his shoulders in regards to test drives. Can't believe they're missing out on that business opportunity.
Thrust is utter bullshit useless quoted number. Utterly totally and cometely meaningles. It depenfs on flow conditiond and propeller!

Toraur on the other hand is what yoi want over rpm range.

 

weightless

Super Anarchist
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Toraur on the other hand is what yoi want over rpm range.
Seems to me that power, which is proportional to torque x rpm and is a measure of how much work can be done in some time, isn't a bad place to start when comparing devices that you want to do work in time.  It's almost like it was designed to for these kinds of comparisons. Not?

 

Beanie 101

Member
64
36
UK
Many of us have observed that "equivalent" gas motors produce more thrust than electric in the service we put them to. They give better speed, better acceleration, and do a better job of driving into wind and seas. If tests produce results that differ from observations then the tests aren't testing the thing being observed.
‘Twas ever thus.

 

allweather

Member
438
82
baltic
Many of us have observed that "equivalent" gas motors produce more thrust than electric in the service we put them to.
Yeah, the "equivalence" label is the worst. It is not exactly rocket science to look at shaft/power and see that a 1000W motor does not equal 5hp, aka 3,7ish kilowatts.

I am more annoyed that there seems to be little useful test data. With which I mean comparisons between "typical" use cases with small yachts. Or at least I have not seen it.
Because for all the shaft power my outboard has I know that even with a "higher thrust/lower speed" prop it can not transmit its full power into the water. Cavitating and dropping in power instead once the boat stops accelerating around 5,5kn no matter how gently I accerlerate.

I know that some guys buy special thrust props for their outboards and get much better results in using the full power the gas engine can provide. Thrust prop in this case being a four blade one with very large area(as much as can be fitted really) and low pitch to keep from dragging down rpms. Doesn't do that much for top speed but acceleration is significantly higher.

Anyway before I digress too much. My... insistence about (low speed) thrust is based in the idea that I am not able to use the full power of my gas engine anyway, so a lower power rating with an electric is potentially not that bad as long as it is better suited to the low flow velocity I see. But as you said the gap still seems to be too big with the espirit's mere 1kW. Even half a 5hp gas outboard is more than that.

 

Beanie 101

Member
64
36
UK
the gap still seems to be too big with the espirit's mere 1kW. Even half a 5hp gas outboard is more than that.
To add to the anecdotal evidence, a few years back a number of 20’ BayRaiders were caught out in an unexpected strong squall during a race in the Carrick Roads near Falmouth (gusting F7 - photo below).  The race was abandoned, we all hurriedly dropped our sails and got ready to motor into the wind to return to the marina.  Several had 2.5hp Suzuki outboards and got back without problems.  I had my (now ex) Torqeedo 1003 with a less than full battery and made quite slow progress on full power.  However, the battery ran out before I could reach home.  I managed to grab hold of a Cornish Shrimper on a mooring and hang on until the rescue boat came back for us. Lesson learned: even in seemingly benign conditions, expect the unexpected and don’t go out without at least one full battery.

11CE1039-C31B-4098-A3A1-7F32D19762CF.jpeg

 
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allweather

Member
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baltic
That sounds unfun. The motor running out of "fuel." not sailing the pictured boats with nice wind!

And does show the limitations powerwise one has to take into considerations. It is just 1kW in the end. The good thing about the h-boat is that you can sail it through most weather pretty well. Even before pulling out reefing and/or tri sails.(don't always carry the tri main/reef but storm jib and anchor most of the time. Prefer that to trying to motor in those winds to be honest)

With an electric however I definitely would be forced to sail or drop the anchor. With the gas one I have some... adventures in 6-7Bft. But honestly in those times it usually comes down to sailing to flat spot of water to drop the sails(sometimes right between the wavebreakers) and then only motor the last couple meters which again doesn't need that much power. But that is me who likes to dock under sails compared to some family members that don't want all that stress. :D

 

Beanie 101

Member
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36
UK
To add to the anecdotal evidence, a few years back a number of 20’ BayRaiders were caught out in an unexpected strong squall during a race near Falmouth.  The race was abandonned, we all hurriedly dropped our sails and got ready to motor into the wind to get back to the marina.  Several had 2.5hp Suzuki outboards and got back without problems.  I had my (now ex) Torqeedo 1003 with a less than full battery and made quite slow progress on full power.  However, the battery ran out before I could reach home.  I managed to grab hold of a Cornish Shrimper on a mooring and hang on until the rescue boat came back for us. Lesson learned: even in seemingly benign conditions, expect the unexpected and don’t go out without at least one full battery.
One BayRaider with a crew of three managed to sail back to the marina under jib and mizzen.  I thought that we were too close to the lee shore to get the boat reefed down quickly and so relied on the motor to claw our way upwind while we sorted ourselves out.  With hindsight and more experience, we might have got back under jib and mizzen too but it’s not always easy to make the right decisions when confronted with the (very) unexpected.

0E98B7DB-B8F6-4202-9FA8-D5CCD004C890.jpeg

 
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Beanie 101

Member
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UK
Torqeedo had never made a profit when they were acquired by Deutz two years ago.  Their financial tribulations appear to continue.  I think that they’re suffering from competition from ePropulsion and perhaps the cost of moving up the scale into much larger saildrive motors.  They have a new(ish) CEO “with a focus on improving profitability”, presumably at Deutz’s behest.

Torqeedo could start by improving their smaller recreational product line.  The announcement of new products for 2021 is unexciting for small boat owners.  There’s a direct drive version of the Travel 1103’s less powerful relative, which is designated the Travel 603.  They say that it’s suitable for boats up to 1 tonne but I think that’s very optimistic.  And that’s it.  No response to eProp’s much higher capacity battery on the Spirit Plus and, direct drive aside, no addressing the plasticky fragility of their smaller outboards.

 
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TwoLegged

Super Anarchist
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No response to eProp’s much higher capacity battery on the Spirit Plus and, direct drive aside, no addressing the plasticky fragility of their smaller outboards.
Torqeedo really needs a major redesign of their product line to fix those issues of capacity and fragility.   But a quest for higher short-term profitability doesn't leave much room for that sort of investment.

They have huge brand recognition, and huge experience.  If they built on that, they could be in a very good place ... but if the investment isn't forthcoming, they will be overtaken.

 

Beanie 101

Member
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UK
if the investment isn't forthcoming, they will be overtaken.
Having been a somewhat disgruntled owner of a noisy Torqeedo 1003 (with two extra batteries) and now a much happier owner of an ePropulsion Spirit Plus (with the new solar controller), I think that they were comprehensively overtaken two years ago.  ePropulsion was founded by ex-Torqeedo managers who obviously thought, and subsequently found, that they could do better at the lower end of the range.  Torqeedo have been spending a lot of effort and money developing seriously big electric motor systems, such as new 50 and 100 kW saildrives.  However, they have neglected the smaller outboards except where they have been forced to improve (eventually and insufficiently) by superior competition.

 

smokeless

Member
88
12
Diesel is 7lbs per gallon, so 140lbs.
Battleborn 100ah batteries are 31lbs each, so 124lbs (source https://battlebornbatteries.com/product/12v-lifepo4-deep-cycle-battery/)
ElectricYacht QuietTorque 10kw motor is 65lbs (source https://electricyacht.com/product/quiettorque-10-electric-motor/)

That's 27 gallons of diesel.  Not bad, but not under 20 gallons.

It looks like your range in ideal conditions (1.5KW @ 5 knots) is about 15nm.  Bump this to 60nm (a reasonable delivery day for racing around here, 12 hours at 5 knots) and you'd need 500lbs of batteries (20KWh) and the total system weight isn't looking quite as attractive.

I'm interested in going in this direction if our diesel ever fails, but it does have big limitations.
One bit of math you're missing here is that he replaced a diesel that weighed 302lbs dry (280 for the motor, 22 for the gear); you can double the battery size of his setup, add the motor weight, and be right around the weight of the yanmar he pulled out. CarCrash's current setup is ~100lbs less than his old diesel before considering fuel weight and works very well for his use case.

Weight wise, it would be a net gain rating wise for a 30nm commute on race day as fuel isn't considered part of the boat weight in a lot of ratings (IRC, ORC, etc).  The question for your 60nm commute is does ~200lbs of rated weight of batteries hurt more than ~60lbs unrated weight of fuel (guesstimate on how much you have sloshing around the tanks to get home)?

Edit: currently in the design spiral of electric vs. diesel for our next boat and it's very close at the moment, especially when you start including a built in hydro generator and the weight of the house bank. The major issue is we can't meet the 10-12 hour motoring requirement at near hull-speed for the offshore event's we'd be doing so it's unlikely to work without battery sizing getting silly.

 
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IStream

Super Anarchist
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Edit: currently in the design spiral of electric vs. diesel for our next boat and it's very close at the moment, especially when you start including a built in hydro generator and the weight of the house bank. The major issue is we can't meet the 10-12 hour motoring requirement at near hull-speed for the offshore event's we'd be doing so it's unlikely to work without battery sizing getting silly.
And that's the issue for most people. Whether it's offshore event requirements or inland cruising, 10-12 hours at hull speed is still gonna call for unreasonable costs and/or bank sizes with current technology. In a few years, the battery cost reductions may make it reasonable but it won't really take off until energy densities double once or twice.

 

Beanie 101

Member
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36
UK
ePropulsion are about to announce the Spirit EVO, which is the same small electric outboard as before, but with hydro-generation capabilities through the propeller at speeds in excess of 4 knots.  Also the throttle will be detachable instead of hinged and will be interchangeable with a remote control.  Details have somehow leaked ahead of the official announcement - see this from a UK distributor Nestaway comment

 
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TBW

Member
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270
I have a Torqeedo 1003 on my 21 ft boat.  Lots of power for short range, max range on a single charge, maybe about 9 miles.  

It needs servicing, it's over heating at higher speeds, but its 7 years old and never been serviced.  I will see what the repair costs...

 




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