Electric Outboards just not there yet?

[dunedin]

I’ve got as far as googling electric outboards, I was under the impression it was Torquedo or nothing.

There’s a YM test of electric outboards on line and there’s loads of choice. The E Propulsion 3hp equivalent is the YM recommended unit, that’s available with hydro regeneration as an option.

If it works as promised a self sufficient outboard with zero servicing etc is very tempting, ignoring the price of course!

Take the “3hp” comparisons with a pinch of salt. The actual mathematical units conversion is 1kW = 1.34hp, so both the Torquedo and ePropulsion are under 1.5hp. The electric outboards do give a lot of low end torque though, and with a suitable prop configuration can give a solid push. However, in the excellent YM tests neither electric outboard could get dinghy onto the plane, as they lack ultimate high end power. By comparison a typical 2.5hp two stroke at full throttle will just break up onto the plane with a single occupant.
So I would suggest the two 1.0 & 1.1 kW motors are good workhouses for a steady pace, but don’t defeat the physics and units at peak power where they are not “3hp equivalent”

 

[[2574]]

Take the “3hp” comparisons with a pinch of salt. The actual mathematical units conversion is 1kW = 1.34hp, so both the Torquedo and ePropulsion are under 1.5hp. The electric outboards do give a lot of low end torque though, and with a suitable prop configuration can give a solid push. However, in the excellent YM tests neither electric outboard could get dinghy onto the plane, as they lack ultimate high end power. By comparison a typical 2.5hp two stroke at full throttle will just break up onto the plane with a single occupant.
So I would suggest the two 1.0 & 1.1 kW motors are good workhouses for a steady pace, but don’t defeat the physics and units at peak power where they are not “3hp equivalent”

I'm sure all that logic is perfectly valid, what I would say as a user is that the Eprop that I have matches the Mercury 3.3hp 2stroke that I had before in day to day use, but once again depends on the user. I've no desire to get a dinghy up on the plane for the way that we cruise - my days of a 460hp planing boat are well in the rear view mirror! The cleanliness and quietness of the Eprop far outweigh any perceived diminished performance as compared to the 2stroke Mercury.

 

[thinwater]

I'm sure all that logic is perfectly valid, what I would say as a user is that the Eprop that I have matches the Mercury 3.3hp 2stroke that I had before in day to day use, but once again depends on the user. I've no desire to get a dinghy up on the plane for the way that we cruise - my days of a 460hp planing boat are well in the rear view mirror! The cleanliness and quietness of the Eprop far outweigh any perceived diminished performance as compared to the 2stroke Mercury.

Roughly translated, "I didn't use the 3.3 HP anyway, so less was fine." However, you might find that even at slow speeds in open water settings you will need more of that HP just to make progress. In harbor, not so much. And then there is a the matter of range. 200 yards to the dinghy dock is one thing, longer explorations or remote anchorages are another.

 

[Tranona]

Take the “3hp” comparisons with a pinch of salt. The actual mathematical units conversion is 1kW = 1.34hp, so both the Torquedo and ePropulsion are under 1.5hp. The electric outboards do give a lot of low end torque though, and with a suitable prop configuration can give a solid push. However, in the excellent YM tests neither electric outboard could get dinghy onto the plane, as they lack ultimate high end power. By comparison a typical 2.5hp two stroke at full throttle will just break up onto the plane with a single occupant.
So I would suggest the two 1.0 & 1.1 kW motors are good workhouses for a steady pace, but don’t defeat the physics and units at peak power where they are not “3hp equivalent”

Horsepower on this type of engine is largely meaningless. It is not the engine that moves the boat but the propeller. Most of the theoretical hp of a small outboard is wasted because it is linked to an inefficient propeller - lots of revs and no go because the small size and high speed of the prop cannot provide thrust to move the boat. You would be shocked if you knew how little measurable hp a Seagull produced at the crankshaft and yet they are quite capable of outperforming other outboards when used on small heavily laden displacement boats (that is in this case an inflatable dinghy). The secret is large reduction ratios leading to low shaft speeds and large diameter flat pitch props. Unsurprisingly this is exactly what a Torqeedo uses.

The "3hp" equivalent is used to indicate to consumers the level of capability of the motor in terms that they understand. Plenty of users of such motors , not least in this thread will confirm it is a valid basis of comparison. As a matter of interest, suspect it was me (and my colleagues) who started this comparator in the late 70s when writing copy for Seagull intended to deal with the pressure to use crankshaft hp as a sizing method. You will find this was the first mention of "hp equivalent" and supported by bollard pull figures, just as electric motors do today. Far more meaningful.

 

[[2574]]

Roughly translated, "I didn't use the 3.3 HP anyway, so less was fine." However, you might find that even at slow speeds in open water settings you will need more of that HP just to make progress. In harbor, not so much. And then there is a the matter of range. 200 yards to the dinghy dock is one thing, longer explorations or remote anchorages are another.

Well, to be honest I’d prefer that you didn’t “translate“ what I’d written, I believe it comprehensible as it is.

 

[dunedin]

Well, to be honest I’d prefer that you didn’t “translate“ what I’d written, I believe it comprehensible as it is.

But it is a pretty accurate precis

 

[xyachtdave]

I’ll buy one and report back.

Look out for a thread ‘This is brilliant..’ or ‘What a waste of 2 grand…’ soon.

 

[dunedin]

I’ll buy one and report back.

Look out for a thread ‘This is brilliant..’ or ‘What a waste of 2 grand…’ soon.

Except that whether it is “brilliant” or not seems to depend hugely on the type of usage - feedback already is that it is a flexible and reliable alternative to an under used / under stressed petrol outboard that suffers from lack of use.
At the other extreme, the small electric outboards are not a viable contender for a tender used as a daily “taxi” for longer trips in the Caribbean - where 10+hp is typically the norm, and planing speeds near essential (bigger electric engines are available, but the cost premium and theft risks increase substantially)
What is your typical usage?

 

[Tranona]

Really no different from any other product. You look at what it has to offer against your requirements and make your decision. Equally those developing the product try to determine what users want and design a product accordingly. Therefore unreasonable to criticise it for not being suitable for other uses for which it was never designed. There is clearly a market for the premium products as that is where the new entrants are aiming.

 

[LONG_KEELER]

I wonder if electric can be brought back to life after a dunking. My Honda has been submerged twice in twenty odd years and still lives. I'm guessing that electric can be sealed better as they require less air than a petrol engine.

 

[Plum]

I wonder if electric can be brought back to life after a dunking. My Honda has been submerged twice in twenty odd years and still lives. I'm guessing that electric can be sealed better as they require less air than a petrol engine.

See post #46. No need to be "brought back to life", this one just worked.

Www.solocoastalsailing.co.uk

 

[Elessar]

See post #46. No need to be "brought back to life", this one just worked.

Www.solocoastalsailing.co.uk

and the battery floats! (on e-propulsion)

 

[SteveGorst]

I bought a 3hp ePropulsion last year and have used it extensively ever since. Far more than I used my old petrol engine. It more or less lives in the boot of my car ready for use as there are no petrol smells. I know it cost twice as much as a petrol engine but over the winter this was effectively cancelled out. One day visiting the yacht on its mooring a strong gust of wind came through and flipped the dinghy while I was working inside my yacht. When I came back to my dinghy it was upside down with the engine propeller in the air. If this had been a petrol engine I reckon it would have been dead and I would have had to buy another. As it was I flipped the dinghy the right way up and drove away.

 

[Travelling Westerly]

I wonder if electric can be brought back to life after a dunking.

My Epropulsion spent 10mins fully submerged, no bringing back to life required, fully waterproof and works like a dream 2 years on. No way would my old 2 stroke have coped as well without significant work required after dunking.

 

[Elessar]

Except that whether it is “brilliant” or not seems to depend hugely on the type of usage - feedback already is that it is a flexible and reliable alternative to an under used / under stressed petrol outboard that suffers from lack of use.
At the other extreme, the small electric outboards are not a viable contender for a tender used as a daily “taxi” for longer trips in the Caribbean - where 10+hp is typically the norm, and planing speeds near essential (bigger electric engines are available, but the cost premium and theft risks increase substantially)
What is your typical usage?

And a Porsche is no good for carrying a piano. What’s your point?

 

[dunedin]

And a Porsche is no good for carrying a piano. What’s your point?

…. That one person buying a small electric outboard and reporting back (per post #67) won’t prove anything much - other than whether it matches their usage requirements, which may differ from others. Lots of user experience on here already.
As has been ascertained, there is no single answer to whether a 1kW electric outboard is optimal or not for differnt needs

 

[Elessar]

…. That one person buying a small electric outboard and reporting back (per post #67) won’t prove anything much - other than whether it matches their usage requirements, which may differ from others. Lots of user experience on here already.
As has been ascertained, there is no single answer to whether a 1kW electric outboard is optimal or not for differnt needs

Ah. Ok your point was to point out the blindingly obvious.
Best write to the Porsche mag in case a potential owner makes the same mistake. With a piano.
Better safe……

 

[dunedin]

Ah. Ok your point was to point out the blindingly obvious.
Best write to the Porsche mag in case a potential owner makes the same mistake. With a piano.
Better safe……

Yawn

PS. The vast majority of Porsches now are SUVs so maybe they do fit the furniture in now

 

[xyachtdave]

…. That one person buying a small electric outboard and reporting back (per post #67) won’t prove anything much…

Hey, I was trying to help!

Intended use….I probably won’t be transporting pianos.

I’d suggest mine would be typical weekend use, to and from a mooring/shore a few times, absolutely maximum would be an hour and a half, 10 minute trips x 9 maybe 1/2 mile each.

Charge it at home.

I reckon that would work for 75% of people on here, if you exclude the cost.

 

[adwuk]

For longer trips, if you have an evening in a pub or restaurant, the staff are usually happy to charge your battery while you have a meal. Worked for us!