Going electric - change my mind

[sailingharry]

Originally Posted by Bullshooter

My Model 3 gets 300 miles of charge in 45 minutes at a Super Charger. That would be 4.7 hours at 64 mph. However, if the battery is nearly out of power and I only charge it for 20 minutes, the charging rate is faster and I could get even closer to your example of 3 hrs x 64 mph of range.

Last I checked Teslas have the best charging rate, the best range, and the best acceleration at the best price. Look up their market share of electric cars.

Some idiots!

I was a bit tongue in cheek. I think Tesla rocks. But I am skeptical of Cigarette's claim (or Rum's quote of their claim) that they can charge their boat for 20 minutes and get 3 hours run time -- at least anything close to "go fast throttle." And if they can, the charge cable would be MASSIVE! Those things burn, what, 20gph, so that's the electric equivalent of 60 gallons of gas in 20 minutes. I don't want to do the unit conversion to see how many kWh that is....

[sailingharry]

Originally Posted by bigskyrad

You might be pleasantly surprised by the boat speed when powered by electric. ICE power is rated at the output shaft of the motor itself but there is some power loss in the saildrive. With electric, the motor output is right at the prop.

You have any documented specs on the loss in the saildrive? Loss equates to heat, and gear transmissions typically have no or minimal cooling systems, which would indicate minimal losses. 1 hp of lost power would be 700W of heat in the transmission -- that would make it scalding hot in very short order! Think how hot a space heater gets on low (about 700W) I suspect the saildrive, or transmission on a conventional drive, has losses well below 1hp -- which is well under 5% for typical marine engines.

[Rumrace]

I have an aging Tesla approaching 5 years old.
Yup everything you attach to an engine used horsepower. Bigger alternator more horse power lost. The thing is it’s not HP to worry about it’s torque and because there is no “stand off” as there is in combustion engines torque is what electric does best.
So the Sea Drive by ZF is the same company who make transmissions 8 speeds for Corvettes and BMW M. They are pros at how much horse power that many gears and clutch packs take up. The sea drive is a whimp on hp consumption. Alternator and water pump are using more.
Power steering on a power boat is about 15HP for single drive.

[saillr]

You are making a big mistake. You will never be happy with the electric. The main reason is not so much trying to travel in calm conditions but how do you get somewhere when the unplanned current is against you or you are just about there in a driving wind and rainstorm and you need to enter a narrow channel and the battery dies. You at times need POWER and lots of it. I have sailed for many, many years and the thing that has saved my boat when things were tough was "The Motor".

[Rumrace]

I fact checked myself and I’m blaming the 127kph winds the rum and my wife made me.
Please forgive me.

[Rumrace]

I have a S model with 47,000klm on it. Ordered 2 weeks before the 3 introduction.
I ordered a 90 and got a 100. Got caught in the evolution. It’s been perfect. I’ve driven to Montreal on a charge no worries and Canada has charging stations Coast to Coast. I’m a hard core motor head Have BMW Old M, Bikes 53 Triumph 69 Harley, marinized LS3 and speed master drive in a barn. Electric has been a leap of faith.
Now we are putting in a huge lithium battery factory to back up all the new electric cars.

[Dieseldude]

Originally Posted by saillr

You are making a big mistake. You will never be happy with the electric. The main reason is not so much trying to travel in calm conditions but how do you get somewhere when the unplanned current is against you or you are just about there in a driving wind and rainstorm and you need to enter a narrow channel and the battery dies. You at times need POWER and lots of it. I have sailed for many, many years and the thing that has saved my boat when things were tough was "The Motor".

The energy density of battery storage is far lower than energy available in diesel fuel. A vessel engine is safety equipment that will get you out of trouble. It is quite easy to keep sufficient fuel in the tanks. Keeping sufficient charge in an electric propulsion battery is not so easy. Extra demands cannot be planned for.



Navigating tight waters and stormy seas without engine available as a back up is asking for trouble. Sure, boats have sailed without engines for millennia, but how many sailors are really up for that now? And how many incidents had there been in the pre engine area? If you're gonna spend big money on propulsion, might as well make it count for keeping yourself safe.


When battery technology is improved to match the energy density of diesel, and at a reasonable cost, it might become feasible to fit electric propulsion.

[catman]

Have you given any thought to removing the engine from the saildrive and adapting an electric motor to the existing saildrive.

[Mauruuru]

Originally Posted by SaylorMade

Alright, I have a 27' sailboat from 1984, with a Volvo Penta MD7B seawater cooled, Saildrive 120S.
The saildrive has multiple issues, and the engine is running without a thermostat, since no one has been able to figure out why it fluctuates wildly in temp with one installed.

I use it for weekend trips and summer holidays, almost always shore power at night, and max 25 nm per day.
I usually use around 20 litres of diesel in a season.

I love the boat, gonna keep it, but something has to be done - propulsion wise.

The boat was originally sold with an 8 HK diesel, even though mine was delivered with an upgrade: MD7B (14 HK). I have never been close to full throttle with it. Normally runs around 1500 rpm giving me 5 knots.

I've been quoted (albeit no one seems to give exact quotes anymore) around 20,000 USD for a new installation of a Volvo D1-13 with S130 drive.

On the other hand I'm looking at an electric propulsion system from ePropulsion. 6 KW pod motor with a 9KWh battery pack and charger. (Shore power remember).
That will be around 15,000 USD including the work done to close the saildrive hole in the bottom of the boat.

So I can save money, and have a what seems to me to a much less complicated system to maintain. Not a plethora of things that can go wrong: generator, pumps of different kinds, fuel contamination, cooling issues etc etc.
I also like the idea of hearing a lot less noise when motoring, and would be happy to trade 1-2 knots of cruise speed on that account.
With the 9KWh battery it will give me plenty of range for the very few becalmed days - as I said, if I am able to sail in almost silence, 3-4 knots is fine with me.

Sales value is not an issue for me, I will keep the boat, and I don't expect to get anything for it when I stop sailing.

So, I'm very close to "add to cart" on the electric system - but I want to hear if I am missing something in my thought process here?
So - go ahead - change my mind

Some info:
The boat: https://sailboatdata.com/sailboat/nordship-808

The engine: (6.0 EVO) https://www.epropulsion.com/pod-drive/

The battery: (E175) https://www.epropulsion.com/e-series-batteries/

Unless the saildrive is also a problem, why not keep it and couple the electric motor to it? An electric motor is going to be a lot smaller and lighter than the diesel.

There are also manufacturers of electric pods that could replace the whole diesel saildrive and still use the hole in the hull. I'd look at that before committing......

[Mauruuru]

For those naysayers an luddites out there who claim the diesel is the only safe way to go I'd remind you that 200 years ago there was no auxilliary......but if you are really worried about it, get a small diesel genset, keep the diesel tank, rip out the diesel engine and replace it with an electric motor. You'll be glad you did---they of course will not be.

[Adelie]

Originally Posted by izzyforreal

I'm always railing against electric conversions. It seems you give up so much for so little. Your cruising range is extremely limited, and getting out of the way of, or powering through a big storm seems like a problem. You, however, seem like the perfect candidate for electric. You don't go far each day and you don't need to motor over long distances should the wind give out. I'd never do it in that boat as it seems like a poor value proposition, but, it's your money. If it were me and my boat, I'd resolve the saildrive issues and install a remanufactured engine. That shouldn't cost you even half of what you've been quoted.

CRUISING range on a sailboat is almost unlimited. Depends on your ability to store provisions.

It is true that MOTORING range at hull speed using an electric motor is severely limited.

For offshore boats willing to go all in on solar, and with a significant installation of batteries, a motoring speed of 2.5-3.0kt could be maintained 24/7 in calm sunny conditions.

For day-sailing EP would be competitive with a diesel without spending an inordinate amount.

[Dieseldude]

Originally Posted by Mauruuru

For those naysayers an luddites out there who claim the diesel is the only safe way to go I'd remind you that 200 years ago there was no auxilliary......but if you are really worried about it, get a small diesel genset, keep the diesel tank, rip out the diesel engine and replace it with an electric motor. You'll be glad you did---they of course will not be.

What does "luddite" have to do with the discussion? Electric boat propulsion is just not developed enough to be practical for most applications. The first steam engines would not have been feasible for boats. They were used for pumping water from mines.


Fitting a capable diesel generator, electric propulsion motor, and battery aboard a small vessel has practical and cost constraints. Room must be found for additional equipment. May work in some cases. But the boat may need to be designed and constructed to accommodate. Efficiency would not by great using a diesel engine to turn a generator to charge batteries to turn an electric motor. A lot of stages of conversion there that lose energy as heat. Directly turning the prop with a diesel engine is comparatively simple and eliminates such losses.


A well designed and well maintained mechanical injected diesel is very reliable. They only need electricity for starting and for running gauges. They have no complex computer and sensor system. They do not require expensive diagnostic equipment. Anyone with basic knowledge and tools can do many repair tasks in any place in the world. Boat equipment should be about reliability, simplicity, and safety. It is not about keeping up with the latest fashions in technology just to prove one's level of sophistication.

[Rumrace]

It’s just a repeat thread same opinions on a rapid changing industry.
Think I’ll skip the next two repeat debates with yesterday’s news

[s/v Jedi]

Originally Posted by Dieseldude

What does "luddite" have to do with the discussion? Electric boat propulsion is just not developed enough to be practical for most applications. The first steam engines would not have been feasible for boats. They were used for pumping water from mines.


Fitting a capable diesel generator, electric propulsion motor, and battery aboard a small vessel has practical and cost constraints. Room must be found for additional equipment. May work in some cases. But the boat may need to be designed and constructed to accommodate. Efficiency would not by great using a diesel engine to turn a generator to charge batteries to turn an electric motor. A lot of stages of conversion there that lose energy as heat. Directly turning the prop with a diesel engine is comparatively simple and eliminates such losses.


A well designed and well maintained mechanical injected diesel is very reliable. They only need electricity for starting and for running gauges. They have no complex computer and sensor system. They do not require expensive diagnostic equipment. Anyone with basic knowledge and tools can do many repair tasks in any place in the world. Boat equipment should be about reliability, simplicity, and safety. It is not about keeping up with the latest fashions in technology just to prove one's level of sophistication.

Sorry, most of what you write here is wrong. Your username seems to indicate you are not open minded and just here to argue, which is senseless so even though my fingers itch for pointing out the errors, I won’t respond to these posts anymore.

[NPCampbell]

A few things ...

The ePropulsion 6kw pod is listed as 9.9HP but 6kw = 8HP. If they are going to use some fictional marketing equivalent horsepower they need to list it.

I think with your usage scenario, the range of the engine will typically be fine. However, this engine is already smaller than half the size of your current diesel. Are you sure you can power against a stiff current long enough to get back to the marina if the wind dies? You may have a 9kw battery but would you risk 100% of it?

Also, the input voltage for this pod is listed as 39-60v. Your battery pack will have to be in that range or you'll lose 10% with a DC-to-DC converter. If your battery pack is setup for the high motor voltages then you'll lose the 10% with a buck converter to drive all of your other house loads unless you add more batteries.

Lastly insurance. I understand dumping a bunch of money into something you love. I've put $20k worth of engines and upgrades into a classic car that I only paid $12k for. However, I have cheap insurance that covers the vehicle and my upgrades. I'd make sure your insurance covers the additions because you are one lightning strike away from losing it all.