Electric Outboards

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fireball

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We're looking at getting an electric Outboard ...

This is (in my mind anyway) a secondary outboard for use on our little inflatable when we're anchored up somewhere, rather than thrashing the hell out of it on our Walkerbay 10 against a spring tide current to get to our mooring .... although it will probably get some of that use as well ....

Anyway - I know there was a test a while back - but I can't afford a torpedo unit .... however, I have come across a couple of units and wondered if others had experience of these budget units...

Bison Series
Minn Kota Endura
Shakespeare SKP
Flover series

Having used a Yamaha M12(?) I've concluded I need something about twice the power to be of use to the Walkerbay, but these tend to get prohibitively expensive ... so I hoping something around the 40-50Lb thrust may suffice.....
 
In the past I have looked in some detail at the specifications and claims made for the Torqeedo range but not the others you mention.

I wont repeat my criticisms of the claims made for the Torqeedos but what I would say is be sure you know what to expect. Don't be seduced by high thrust figures quoted for relatively low power engines. At the end of the day it's power that counts IMO.

Look at the range you will get from a fully charged battery at realistic speeds and also consider the weight if the batteries, how you will recharge them and the recharging times.
Compare what you will achieve with an electric outboard and a fully charged battery with what a small petrol powered outboard will deliver on a couple litres of fuel and also how long it takes to recharge the battery compared with how quickly you can refill a petrol tank.

If I wanted to push a small dinghy at slow speed for shortish distances in almost total silence then an electric outboard may be just the ticket but otherwise I'd stick with petrol power.
 
I recently bought a flover 33lb thrust motor as a cheap stop-gap while I got my suzuki 2.2hp 2-stroke fixed. It is used on a bombard AX2 2.4 metre inflatable to get me a few hundred yards to my mooring. There can be a considerable tide running. First some sums, which I will do for the flover 45lb thrust version, since that is the thrust you suggest. Flover state that the 45lb thrust model draws 40 amps max. (at 12 volts). That's 480w, or about 0.6 hp. But that's input power, not output. Assuming 80% efficiency, that means about 1/2 hp output. Not much, but I then considered that one-up, with a sailing bag, spare petrol can, etc. the suzuki will get the Bombard planing at three-quarter throttle, so I thought - OK I'll get one. Admittedly I bought the 33lb thrust model.

Out on the water it moved the tender at about 3 knots flat out. I remember thinking that if there was any kind of tide running, or even much of a head-wind, I'd be going backwards. They are called trolling motors, and that's where they belong. Alongside a petrol outboard on an angling boat on a large lake. And another thing - If it draws 40 amps, that means one hour of operation will drain all of the usable power from an 85 ah leisure battery.
 
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Look at the range you will get from a fully charged battery at realistic speeds and also consider the weight if the batteries, how you will recharge them and the recharging times.

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Yup - that is a little concern - we currently have a 110amp leisure battery and a seperate starter - so I'd have to add a 3rd charging point for the leccy ... whilst in home port it isn't a problem as there is a shed we use ...

The Walkerbay currently gets to 4knots at around 1/2 throttle of a 2Hp unit - at slack tide (measured on GPS) ... the tide doesn't run that fast ... and I usually get out of the tide pretty quickly if it is going against us.

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If I wanted to push a small dinghy at slow speed for shortish distances in almost total silence then an electric outboard may be just the ticket but otherwise I'd stick with petrol power.

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Sounds about right - I don't intend to get rid of the Honda ... but for running up and down Beaulieu river or similar it is just too flippin noisy!!
 
It seems to function perfectly. But then I only used it twice. As soon as I got the Suzuki going again I was much happier - plenty of power in reserve.
You really do need to give careful thought to how many extra batteries you will have to carry, and how you will charge them. I gave the figures above. You will need one 85 amp-hour battery per hour of use, and the ability to recharge.
 
Ta /forums/images/graemlins/smile.gif

Spoken with the guy who owns the Yamaha - he has an 85Ah battery which would last him an hour - interestingly he says that it isn't worth running on lower speeds as there is an efficiency loss.....
For onboard charging he just uses a solar panel, and has a Halfords battery charger for use in the shed on shore.

He seemed to think that a 110Ah battery should be ok for a 45 or 55Lb model - would probably give about the same run time ... we don't intend to heavily use it so I'm not going to get all stressed about onboard charging - it can just go in parallel with the domestic and we'll have to run the engine more (now - does this battery charging get classed as propulsion or not when it comes to claiming domestic red diesel use?!) - so no big problem then.

1 battery should be fine - I certainly don't intend to go off for hours and hours with just an electric - anyway, still got the oars ... or just drift on the tide (assuming it is going the right way!)
 
Fireball, if I were you I would buy yourself a wee 2 stk out bourd and dont waste your money on an electric, and I am talking from experience as I used one on grp resevoir fishing boats up to 14' with no trouble at all, but when I tried it on my 2.7m inflatable it was a waste of time, and that was on very calm water with very little tide running.
I even gave it the benifit of the doubt and tried it a couple more times, then bought a new outboard.
Even with a new 110ah deep cycle batt, it was crap.
Just been honest.
C_W
 
We use a 54lb thrust regularly - a Manta 54MX. 60 minutes good use from a 100AH battery but will damage the battery if used for much longer without charge. Yes the noise level is lovely, yes it is really cool but an inflatable has so much windgae you will need to row as well if you are against wind and tide. Ours cost #138 with a UK 2 year guarantee. Don't buy the Flover it's #100 more for the same piece of kit!
 
I've got a 2Hp outboard ... can't be arsed with 2 stroke oil ... the honda is more than capable of being there for the most part.
You said your electric couldn't shift your 2.7m inflatable - what size electric and how loaded was the inflatable?! We've tried a 12Lb thrust on a walkerbay and the owner uses it on his own solid and inflatable, but agrees that the power is a little too low for us - not by much though...
 
I have oars ... but don't want to row the length of beaulieu river .... it's hardly a romantic row when you're cramped up in a 2.4m inflatable and SWMBO is perching on the stern trying not to fall in as I splash her with my imperfect rowing technique ....
2Hp petrol is fine for delivery, but flippin noisy - hence we WANT an electric - it was the make/model I wanted opinions on - not whether to have one or not!!!
 
Subject: Electric Outboard...

Hi, Fireball. Was just wondering how u got on with your electric outboard search? I have exactly he same requirement as you. Want something to cleanly and quietly push a 2 metre inflatable tender from cheap mid river pontoons such as in Yarmouth harbour, on the Hamble or at Bucklers Hard from our 30ft Colvic to the pub! Approx running time 10-15 mins each way (300 metres max?) Im considering a Rhino or Bison 40lb or 55lb thrust. One concern is that the 55 seems to have a rather long shaft and consumes quiet a lot more amps than the 40. How did your experimentation go? Like you I have a 2.5HP Mariner, but want to go clean and quiet.

Thanks in advance...
 
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