Torqeedo electric outboard test

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steveellis917

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The test took place in Poole Harbour on 23/10/08. The boat is a plywood double-ender, 14' 6" long, 4' 6" beam, weight about 200 pounds. The Torqeedo motor is the Travel 801 with the lightweight Lithium battery, which can be fully discharged without damage, and fully or partially recharged without 'memory effect' reducing the capacity of the battery over time. The weight of the motor and battery is 27 pounds.

The trial involved motoring with the tide for half a mile, then turning back against the tide, turning again, and repeating. Initially the sea was glassy smooth, but the breeze filled in during the next hour to about Beaufort 2, blowing in the same direction as the tide.

Initially I tested for maximum thrust, which showed that the motor will drive the hull at 5 knots. I then dropped back to 3.7 knots and fixed the throttle. Downtide the speed increased to 4.2 knots, uptide it dropped to 3.2 or 3.3 knots. After 1 hour and 20 minutes the battery was empty, for a distance travelled of 4.9 nautical miles, averaging 3.7 knots. (all measured by GPS).

This result is pretty much in line with the manufacturer's published claims. Endurance would be better at a lower speed, and could be improved on a bigger craft by using several normal 12-volt lead batteries instead of the lightweight Lithium one. The trial confirms that the motor provides a clean and quiet 'get you home' service in estuarine waters.

Steve Ellis
 
Sure, Try it on a 2.7mtr inflatable (not RIB) and see how it performs, you will be very dissapointed as I was, with my Minkota, 46Lb thrust motor.
 
Downsides are

£1150 compared with petrol outboards starting around £340 for which you get 2½ hp

Very low power, less than ½hp,

Takes 5 hours to refuel and needs access to mains electricity. Petrol outboard can be refuelled in a couple of minutes from a can.

Battery will have a limited lifespan compared to a petrol tank.
 
Your 46lb motor is one sixth the power of the Torqeedo 801. That may account for some of the difference in performance /forums/images/graemlins/grin.gif
 
[ QUOTE ]
Downsides are

£1150 compared with petrol outboards starting around £340 for which you get 2½ hp

Very low power, less than ½hp,

Takes 5 hours to refuel and needs access to mains electricity. Petrol outboard can be refuelled in a couple of minutes from a can.

Battery will have a limited lifespan compared to a petrol tank.

[/ QUOTE ] Hang on here chaps, the Torqeedo is a completely different beast to a 12v trolling motor. The 24v AC motor Torqeedo 801 is (measured at the prop) equivalent to a 2.2hp petrol outboard. It cannot be refueled anything like as quickly as a petrol unit, but is lighter, quieter, cleaner for the user, more easily transported and far far sexier! I had a go with one last summer and was amazed at how powerful it was. It is nothing like our 56lb 12v Rhino which is like a hand powered egg whisk by comparison. The Torqeedo 801 is less than £900. But that is expensive compared to a new petrol unit.
 
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Torqeedo 801 is (measured at the prop) equivalent to a 2.2hp petrol outboard.

[/ QUOTE ] This is one of the misleading bits of data they give for these electric outbords. It is said to have a thrust or static bollard pull equivalent to a 2hp petrol outboard but it's propulsive power is only 350 watts (equal to 0.47 hp) There is not a lot of call for pulling static bollards, what counts when you actually want to go somewhere is the power.

[ QUOTE ]
was amazed at how powerful it was

[/ QUOTE ] Easily amazed if less than ½hp is all it takes!
 
neat little report, but cynical ol' me would like to know if you have any links to the manufacturer or vendors please.
 
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This is one of the misleading bits of data they give for these electric outbords. It is said to have a thrust or static bollard pull equivalent to a 2hp petrol outboard but it's propulsive power is only 350 watts (equal to 0.47 hp) There is not a lot of call for pulling static bollards, what counts when you actually want to go somewhere is the power.

[/ QUOTE ] I know buggger all about hp / watt equivalents, so I can only go by actual hands on experience. The 401 (the smallest they make) shoved the inflatable along like my 3.3 Tohatsu used to. The 801 is way too powerful at full throttle for the Seago we have. Maybe its something to do with the mystery of torque in an electric motor, but like I said, I know nothing of the theory, only what i have actually experienced.
 
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neat little report, but cynical ol' me would like to know if you have any links to the manufacturer or vendors please.

[/ QUOTE ]

I can vouch for Steve who is given to well thought out experimentation in small sail boats. I reckon that this motor is well suited to the short duration use he plans for it on his present light and easily driven sailing boat. In the 1960's a nominal 1.5hp petrol motor would have been thought more than adequate for this application (which may well have only put out .75hp especially if it was a Seagull)

The 801 should be a "clean" alternative on short journeys in inflatables too although for reasons of cost, duration, back up battery weight and ultimate battery life, with the present state of the art, personally I would rather have a petrol motor.
 
You're right to be sceptical, Vic, because electric outboards have historically been fairly poor devices, and I have to say I was initially doubtful about the Torqeedo. However, it does appear that the Torqeedo might be quite good. I haven't tried one, but there are a number of YouTube videos which would seem to indicate it's a fairly powerful machine. Take a look here, here, here and here. I'm almost convinced. Let's hope the price drops!
 
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I know buggger all about hp / watt equivalents

[/ QUOTE ] 1 hp = 746 watts As plain and simple as that .

If your 3.3 hp petrol outboard could perform no better than an electric outboard of less than ¼hp then there was something seriously wrong with it or you had a propeller that was quite unsuited to the use.

There seems little doubt that the Torqeedo have taken electric outboards to a higher level than their predecessors. It's the battery that's the limiting factor as far as I can see but one day when battery technology has advanced considerably from where it is at present they could become a serious rival to small petrol motors. You never know electric motor cars may even become a serious proposition.
 
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If your 3.3 hp petrol outboard could perform no better than an electric outboard of less than ¼hp

[/ QUOTE ] All I can say Vic, is if you are right about the Torqeedo only being 1/4hp then by golly 1/4hp is a lot. I'm a right old tubby and with two adults, a child and a Jack Russell the Seago was flying along with the Torqeedo on the back. And you reckon that it's only a 1/4 hp? Must be a quarter of a particularly good horse. How come the inflatable shifts at 2 knots with the pathetic 56lb thrust electric outboard we let the kids play with - that uses 25% of the juice of the Torqeedo - makes it 1/16th of a hp by those calculations. Meethinks something isn't quite right /forums/images/graemlins/grin.gif
 
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Meethinks something isn't quite right

[/ QUOTE ] Well you can look at the figures on the Torqeedo website

Taking the Travel range they state input powers of 400watts and 800 watts for the 401 and 801 models respectively and propulsive powers of 175 watts and 350watts (giving an effeiciency of 44% for both models.)

Now since 1 hp = 746 watts a bit of simple arithmetic gives you propulsive powers of 0.235 hp and 0.469 hp and electrical power consumptions equal to 0.536 hp and 1.07 hp.

What do you suggest is wrong with that? Torqeedos figures and simple arithmetic!
 
When looking to buy an outboard for an inflatable dinghy last year I seriously considered the Torqeedo but decided I would definately require a second spare battery, which just made the whole thing too expensive.

As regards comparing horsepower ratings I think the actual whole performance of the machine with power and torque at different revs (and the prop characteristics) needs to be considered. My old boat displacing about 3 tons achieved about 4 kn with its 5 hp diesel but when I had to borrow a 4hp petrol outboard to get to a boatyard it wouldn't push it more than about 2 kn
 
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