Elco 50hp electric outboard

wombat88

wombat88

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Does anyone have any experience or knowledge of this motor?

Seems to be the only 50hp electric outboard out there that I can find.

Just wondering...

EDIT, just found more, I obviously know nothing!
 
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What are you thinking of powering with a motor like this?
And what range do you need?

Worth doing a few sums on the power demand, and the likely battery bank and cable sizes necessary to power something like that.

Smaller electric drives typically operate at nominal 48V - broadly the limit in many places for DIY maintained systems. But these have an effective upper power limit of about 15kW before the current flows and hence cable sized become enormous (15kW is around 300A with a 48V system).
With bigger motors you need much higher voltages - some cars run at 400V or more. Which is fine in road car, but typically not a good mix with salt water in a small boat, particularly with an outboard.
A professionally installed and maintained inboard system is possible - but expensive and needs very careful safety systems to handle risk of flooding.
And check you can get insurance - reports of some insurers not being willing to cover electric propulsion unless professional/factory fitted.
 
I am pondering powering an old Hardy Pilot that we use.

Mostly used in harbour and perhaps a mile or so offshore. Very few trips out over 4 hours. Displacement speeds often against quite strong tides.

Cost of 50hp electric outboard alone roughly the same as a new 50hp petrol unit but batteries etc significant extra. Value of the boat somewhat less than value of engine. Current outboard past its best. Plenty of space for batteries.

Obviously such an expensive installation will not increase the value of the boat by anything like the £££s spent so financially it doesn't make sense...but...

I just wonder if anyone has done something similar?
 
50hp = 37 kW... even at half power...18.5kW x 5hrs = 92.5 kWhrs. At 48v this gives 1927 usable Ahrs.
Lead Acid batteries dont like being discharged more than 80%, so you need a total battery capacity of around 2400 Ahrs.
This would weigh approx 3500Kg... Think it might sink a Hardy Pilot!
Cost ~ £15k-20k for the batteries alone
Ouch!
 
wombat88 said:
I am pondering powering an old Hardy Pilot that we use.

Mostly used in harbour and perhaps a mile or so offshore. Very few trips out over 4 hours. Displacement speeds often against quite strong tides.

Cost of 50hp electric outboard alone roughly the same as a new 50hp petrol unit but batteries etc significant extra. Value of the boat somewhat less than value of engine. Current outboard past its best. Plenty of space for batteries.

Obviously such an expensive installation will not increase the value of the boat by anything like the £££s spent so financially it doesn't make sense...but...

I just wonder if anyone has done something similar?
Click to expand...
Currently I suspect only the very rich. But even then smart money buying electric powered motor boats are heading for hydrofoil boats - works well with electric as high peak power to get airborne, then very efficient once up on foils.
Or at the other end canal boats pottering slowly using 10kW and lots of cheap lead acid batteries as ballast.

Conventional solutions sound better for you
 
wombat88 said:
I am pondering powering an old Hardy Pilot that we use.

Mostly used in harbour and perhaps a mile or so offshore. Very few trips out over 4 hours. Displacement speeds often against quite strong tides.

Cost of 50hp electric outboard alone roughly the same as a new 50hp petrol unit but batteries etc significant extra. Value of the boat somewhat less than value of engine. Current outboard past its best. Plenty of space for batteries.

Obviously such an expensive installation will not increase the value of the boat by anything like the £££s spent so financially it doesn't make sense...but...

I just wonder if anyone has done something similar?
Click to expand...
I really don't think you need that kind of power for displacement speeds in a small boat. I have a Hardy 25 which came with a 50hp outboard and it was way overpowered for inland and estuary use. I sold the outboard and fitted a 6kW E-propulsion outboard and 48V 300Ah LiFePO4 battery. The idea was to fit a second outboard if I needed more power, so far haven't felt the need. If there are strong tides use them to your advantage, out on the ebb, back on the flood.
 
We used to have a Buckingham 20 (heavy for it's size) - was woefully overpowered with an 8HP on a canal!

However, it felt just the right power on the Norfolk Broads - and underpowered on a big open stretch of water.

Fundamentally, if you only want displacement 4 or 5 hp is plenty, so a 9-15hp is going to be running well within its economical range - may even be overpowered depending on speed limit.

Key is to prop it right - most outboards are supplied with a prop designed for a higher speed (so a 9.9 is propped for an inflatable for example) so a lower pitched prop might be much more suitable. This is where the high-thrust type motors come into their own as they usually have a higher thrust, lower pitched prop and a larger gearcase - which for a slower heavier boat is more suitable.

Indeed if you want displacement against a strong tide, you need a high enough thrust motor to power through it bearing in mind it doesn't matter how strong the tide is, you aren't going to power over the top of it and plane - so it's a myth that more power will fight the tide.... If the tide is running at 12knts and your max displacement is 8knts you'll be going backwards no matter how big the engine unless you an overcome it and plane.
 
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