Electric motor conversion

[pete c]

Originally Posted by cgm12mgc

We get it, you’re no fan of electric motors. You can stick to diesel... I do in my other boats. People survived for thousands of years without a motor in their boat and as I have stated, mine is to get out of the marinas and under bridges etc. don’t like it? Don’t do it.


Same concept as what you’re saying, I can run my 61’ sportfish wide open throttle for a few hours but i’m up shi*ts creek when I run out of diesel at a burn rate of 120 gallons an hour... atleast with electric I can refill while on anchor 👍🏻

THIS^^^^^

Whenever the e-aux power discussion comes up, we get the diesel fanboys talking about how you are gonna need that 25hp diesel running flat out for 8 hrs to outrun the storm. e-drive is SUICIDAL!!!!


Let me start by saying I am a HUGE diesel fanboy. I drive a VW TDI. And while I agree that diesels do have that advantage and if I was going to regularly go offshore, I'd have one, blue water sailors are the exception, not the rule. And even if you do go offshore, if you are on the right boat, worst case, that storm does run you down, you just heave to and enjoy the ride!!!! Just like in the old days before ICEs and weather satellites.

Now on to why I am here.

A friend of mine has a Pearson 27. It's Westy is a bit under the weather so to speak. Likely ready for anchor duty.

I am trying to sell him on going e-drive and have volunteered to do the conversion for him.

I told him a 10kw 48v bldc motor is adequate. Actually, I believe it may be a little overkill. He seems to think it isn't enough. He even told me, his 18hp westy isn't really enough when trying to get home into a stiff headwind.

First off, I am pretty sure he has an 11hp motor unless a previous owner did an upgrade and from what reading I have done on the subject, it seems the 3hp/ton is the general rule. The P27 only displaces 5200 lbs.

Any recommendations on what to go with appreciated.

The questions I have are;

Should he buy a full motor/controller kit? Is there much savings to be had by buying individual pieces and putting it together? I am an electronics tech, so I am comfortable wiring it up myself.

Also, I have a stockpile of 48v UPS battery packs. These packs consist of (4)12v 7.2ah SLA batteries. They are not new, but useable.

I get these because in my job as a tech, I am frequently replacing these packs when the UPS gets a bad battery warning. When I take these "bad" packs apart, I frequently find that 2-3 of the batteries are still good, but since they are wired in series, 1 bad battery takes it out.

So, I stock pile the good ones and put together usable packs.

Each pack is roughly 24x6x4 inches long and about 30 lbs.

8 packs in parallel would give me a theoretical 48v 230ah battery bank. I understand the batteries are used, so maybe I only have 150ah. I would think is more than enough for aux duties on a boat which rarely if ever wanders outside Long Island sound. If it isn't enough, I could always add a few more packs.

His slip is about a 1/4 mile up a river with very little current. So this thing shouldn't have to work too hard.

Assuming this works well and the cobbled together battery pack is troublesome, we could always switch over to something like used nissan Leaf Li ion packs which have way more ah/lb.


Would like to hear anyone's thoughts on this plan.

[pete c]

Originally Posted by GrowleyMonster

Why not leave the diesel in place, as long as it runs? You can install pillow block bearings and a pulley on the prop shaft, and drive it with a belt from an electric motor. Depending on your transmission. Consult your mechanic. Anyway with the diesel stopped and transmission neutral, the electric motor turns the prop shaft, or charges your batteries under sail if regen is on. With the diesel running, it turns the prop shaft and turns the electric motor which charges the batteries if regen is on. You get the economy, instant on with no warmup, and quiet operation (and NO minimum idle speed) of the electric when desired, and the long range of the diesel when needed. Add enough solar and you reduce your dependence on the diesel.



Don't get rid of the diesel until it is dead and not worth rebuilding. Then you can switch to pure electric or solar electric. That's my suggestion.

Glad someone else has this thought. To my knowledge, I don't think anyone is doing this from the factory, which seems odd. I think such a hybrid drive is perfectly suitable for sailboats.

I would add one additional feature. I would add a clutch on the prop shaft which would decouple the drivetrain from the prop. This would allow running the diesel to power the generator when propulsion is not needed. This would be handy when at anchor in very warm places so power the AC/fridge if there was not sufficient wind/sun to do so.

[Adelie]

Originally Posted by pete c

Glad someone else has this thought. To my knowledge, I don't think anyone is doing this from the factory, which seems odd. I think such a hybrid drive is perfectly suitable for sailboats.

I would add one additional feature. I would add a clutch on the prop shaft which would decouple the drivetrain from the prop. This would allow running the diesel to power the generator when propulsion is not needed. This would be handy when at anchor in very warm places so power the AC/fridge if there was not sufficient wind/sun to do so.

What you are discussing is a parallel hybrid system. All the design work currently is for serial hybrid systems which suffer from significant efficiency losses.

The EU did research on this and determined that parallel had a bunch of advantages generally. https://cordis.europa.eu/project/id/233718/reporting

Betamarine has parallel hybrid systems for retrofit.

James Baldwin of AtomVoyages has retrofit at least one parallel system with the diesel replaced with an electric motor and a high thrust outboard installed at the stern in the outboard-inboard motorwell system he developed.

[GrowleyMonster]

Originally Posted by pete c

THIS^^^^^

Whenever the e-aux power discussion comes up, we get the diesel fanboys talking about how you are gonna need that 25hp diesel running flat out for 8 hrs to outrun the storm. e-drive is SUICIDAL!!!!


Let me start by saying I am a HUGE diesel fanboy. I drive a VW TDI. And while I agree that diesels do have that advantage and if I was going to regularly go offshore, I'd have one, blue water sailors are the exception, not the rule. And even if you do go offshore, if you are on the right boat, worst case, that storm does run you down, you just heave to and enjoy the ride!!!! Just like in the old days before ICEs and weather satellites.

Now on to why I am here.

A friend of mine has a Pearson 27. It's Westy is a bit under the weather so to speak. Likely ready for anchor duty.

I am trying to sell him on going e-drive and have volunteered to do the conversion for him.

I told him a 10kw 48v bldc motor is adequate. Actually, I believe it may be a little overkill. He seems to think it isn't enough. He even told me, his 18hp westy isn't really enough when trying to get home into a stiff headwind.

First off, I am pretty sure he has an 11hp motor unless a previous owner did an upgrade and from what reading I have done on the subject, it seems the 3hp/ton is the general rule. The P27 only displaces 5200 lbs.

Any recommendations on what to go with appreciated.

The questions I have are;

Should he buy a full motor/controller kit? Is there much savings to be had by buying individual pieces and putting it together? I am an electronics tech, so I am comfortable wiring it up myself.

Also, I have a stockpile of 48v UPS battery packs. These packs consist of (4)12v 7.2ah SLA batteries. They are not new, but useable.

I get these because in my job as a tech, I am frequently replacing these packs when the UPS gets a bad battery warning. When I take these "bad" packs apart, I frequently find that 2-3 of the batteries are still good, but since they are wired in series, 1 bad battery takes it out.

So, I stock pile the good ones and put together usable packs.

Each pack is roughly 24x6x4 inches long and about 30 lbs.

8 packs in parallel would give me a theoretical 48v 230ah battery bank. I understand the batteries are used, so maybe I only have 150ah. I would think is more than enough for aux duties on a boat which rarely if ever wanders outside Long Island sound. If it isn't enough, I could always add a few more packs.

His slip is about a 1/4 mile up a river with very little current. So this thing shouldn't have to work too hard.

Assuming this works well and the cobbled together battery pack is troublesome, we could always switch over to something like used nissan Leaf Li ion packs which have way more ah/lb.


Would like to hear anyone's thoughts on this plan.

For a Pearson 27 yeah a 10 or 12kw motor is about right, IMHO. Some would say a 5kw motor is good for that size boat but you have almost zero energy penalty for having the bigger motor. The bigger motor dissapates heat better and will last longer. The bigger motor gives you somewhat higher peak power, of course. The extra weight of the bigger motor is trivial. The cost is maybe a couple hundred more. I would go with the bigger motor.

That would not be my choice for batteries, but you already have them, so sure, use them.

Conventional wisdom is to use a 48v system for boats under 35' or so, to stay under the nominal 50V threshhold, and go for significantly higher voltages on larger boats, for the higher efficiency of high voltage systems. It is also usually said that if you must go over 50V, you should go way way over 50V. I am starting to see reason to go say 96v, 120v or maybe even 144v on smaller boats, though. For one thing, the rated full power of BLDC motors is often given at 72v, Second, you just can't get away from the fact that 10kw of power usage at 48v is over 200A current. That's a lotta juice, and lots of copper losses. Peukert losses, too, get really crazy at such high discharge rates. At 96v, you need half the current. At 144v, a third the current. 192v you need a quarter of the current. Smaller cables can be used. Motenergy has some BLDC motors that can run at 144v, and Kelly has some sine wave controllers that will handle that voltage. If I were doing it all over again, I would probably go higher voltage even on a very small boat, at least 72v nominal, but probably 96v.

When you don't need much range under power, it is much easier to get a reasonable speed under power with a reasonable size bank. 1/4nm out and 1/4nm back in, is quite doable indeed, with just shore power charging.

If the diesel still runs, I recommend keeping it. Set this up as a parallel hybrid configuration. Keep a few gallons of fuel in the tank. The E-drive will keep your friend from having to put more hours on his elderly diesel, but if he needs the range or the salvaged batteries fail, he can crank up the Westerbeast. Also the electric can take a load off the diesel, running both together, under adverse conditions.

I sourced my components separately and I believe if you take your time, you can put a system together for less $ by shopping around for the components rather than go for a kit. Of course you must know what you are doing and understand EP and three phase synchronous motors, which apparently you do.

A couple of cautionary hints. Insulate, insulate, insulate. Shield shield, shield. I burnt up a pair of expensive MOSFETS when a coffee can full of laundry quarters got knocked over and I didn't see that one had landed on the controller phase terminals. The next time I ran the motor, or tried to, it was fireworks. I also melted a metal watchband. While it was on my wrist. Owie. I posted pics somewhere of the huge blisters on my wrist. I was working on my battery connections. 48v can weld wrenches and screwdrivers. And ventilate. Battery compartments need to be ventilated. With a good blower going anytime the batts are charging or discharging, you will get a lot less green gunk on your terminals and cables. Finally, use the biggest cables you can physically fit into the system. I used 2/0 welding cable for my 48v system. It is really flexible and easy to work with. Plus you can get it in black or red, for the DC side. More finally, get some good crimpers and crimp terminals well, and tighten them good on the battery posts. Remember to insulate. I don't know if the little green and red felt washers actually do any good or not, but they are cheap so I used them anyway.

[GrowleyMonster]

Originally Posted by pete c

THIS^^^^^

Whenever the e-aux power discussion comes up, we get the diesel fanboys talking about how you are gonna need that 25hp diesel running flat out for 8 hrs to outrun the storm. e-drive is SUICIDAL!!!!


Let me start by saying I am a HUGE diesel fanboy. I drive a VW TDI. And while I agree that diesels do have that advantage and if I was going to regularly go offshore, I'd have one, blue water sailors are the exception, not the rule. And even if you do go offshore, if you are on the right boat, worst case, that storm does run you down, you just heave to and enjoy the ride!!!! Just like in the old days before ICEs and weather satellites.

Now on to why I am here.

A friend of mine has a Pearson 27. It's Westy is a bit under the weather so to speak. Likely ready for anchor duty.

I am trying to sell him on going e-drive and have volunteered to do the conversion for him.

I told him a 10kw 48v bldc motor is adequate. Actually, I believe it may be a little overkill. He seems to think it isn't enough. He even told me, his 18hp westy isn't really enough when trying to get home into a stiff headwind.

First off, I am pretty sure he has an 11hp motor unless a previous owner did an upgrade and from what reading I have done on the subject, it seems the 3hp/ton is the general rule. The P27 only displaces 5200 lbs.

Any recommendations on what to go with appreciated.

The questions I have are;

Should he buy a full motor/controller kit? Is there much savings to be had by buying individual pieces and putting it together? I am an electronics tech, so I am comfortable wiring it up myself.

Also, I have a stockpile of 48v UPS battery packs. These packs consist of (4)12v 7.2ah SLA batteries. They are not new, but useable.

I get these because in my job as a tech, I am frequently replacing these packs when the UPS gets a bad battery warning. When I take these "bad" packs apart, I frequently find that 2-3 of the batteries are still good, but since they are wired in series, 1 bad battery takes it out.

So, I stock pile the good ones and put together usable packs.

Each pack is roughly 24x6x4 inches long and about 30 lbs.

8 packs in parallel would give me a theoretical 48v 230ah battery bank. I understand the batteries are used, so maybe I only have 150ah. I would think is more than enough for aux duties on a boat which rarely if ever wanders outside Long Island sound. If it isn't enough, I could always add a few more packs.

His slip is about a 1/4 mile up a river with very little current. So this thing shouldn't have to work too hard.

Assuming this works well and the cobbled together battery pack is troublesome, we could always switch over to something like used nissan Leaf Li ion packs which have way more ah/lb.


Would like to hear anyone's thoughts on this plan.

For a Pearson 27 yeah a 10 or 12kw motor is about right, IMHO. Some would say a 5kw motor is good for that size boat but you have almost zero energy penalty for having the bigger motor. The bigger motor dissapates heat better and will last longer. The bigger motor gives you somewhat higher peak power, of course. The extra weight of the bigger motor is trivial. The cost is maybe a couple hundred more. I would go with the bigger motor.

That would not be my choice for batteries, but you already have them, so sure, use them.

Conventional wisdom is to use a 48v system for boats under 35' or so, to stay under the nominal 50V threshhold, and go for significantly higher voltages on larger boats, for the higher efficiency of high voltage systems. It is also usually said that if you must go over 50V, you should go way way over 50V. I am starting to see reason to go say 96v, 120v or maybe even 144v on smaller boats, though. For one thing, the rated full power of BLDC motors is often given at 72v, Second, you just can't get away from the fact that 10kw of power usage at 48v is over 200A current. That's a lotta juice, and lots of copper losses. Peukert losses, too, get really crazy at such high discharge rates. At 96v, you need half the current. At 144v, a third the current. 192v you need a quarter of the current. Smaller cables can be used. Motenergy has some BLDC motors that can run at 144v, and Kelly has some sine wave controllers that will handle that voltage. If I were doing it all over again, I would probably go higher voltage even on a very small boat, at least 72v nominal, but probably 96v.

When you don't need much range under power, it is much easier to get a reasonable speed under power with a reasonable size bank. 1/4nm out and 1/4nm back in, is quite doable indeed, with just shore power charging.

If the diesel still runs, I recommend keeping it. Set this up as a parallel hybrid configuration. Keep a few gallons of fuel in the tank. The E-drive will keep your friend from having to put more hours on his elderly diesel, but if he needs the range or the salvaged batteries fail, he can crank up the Westerbeast. Also the electric can take a load off the diesel, running both together, under adverse conditions.

I sourced my components separately and I believe if you take your time, you can put a system together for less $ by shopping around for the components rather than go for a kit. Of course you must know what you are doing and understand EP and three phase synchronous motors, which apparently you do.

A couple of cautionary hints. Insulate, insulate, insulate. Shield shield, shield. I burnt up a pair of expensive MOSFETS when a coffee can full of laundry quarters got knocked over and I didn't see that one had landed on the controller phase terminals. The next time I ran the motor, or tried to, it was fireworks. I also melted a metal watchband. While it was on my wrist. Owie. I posted pics somewhere of the huge blisters on my wrist. I was working on my battery connections. 48v can weld wrenches and screwdrivers. And ventilate. Battery compartments need to be ventilated. With a good blower going anytime the batts are charging or discharging, you will get a lot less green gunk on your terminals and cables. Finally, use the biggest cables you can physically fit into the system. I used 2/0 welding cable for my 48v system. It is really flexible and easy to work with. Plus you can get it in black or red, for the DC side. More finally, get some good crimpers and crimp terminals well, and tighten them good on the battery posts. Remember to insulate. I don't know if the little green and red felt washers actually do any good or not, but they are cheap so I used them anyway.

With a newly installed DIY EP system, it is good to have an outboard for backup. With an ailing but still running diesel, you could just keep the diesel for now, instead. A pulley on the prop shaft for a belt, and bobs yer uncle. Switch to a fixed 3 blade. For now, pitch and diameter chosen to suit the diesel.

[Rumrace]

Folks calculating horse power for electric miss the torque.
I keep thinking it’s 3 years too soon for electric. Probably wrong but I’ve seen too many surplus level motors used they had lying around.
When I see a car alternator as a wind generator same thing. It’s likea home made fax machine soon to be obsolete.
Cars yes but at least 3 are lying.
The quips in this forum often deny clear fact but I think few companies in Electric Boats are focussed.
To counter those concerns buying a new diesel which would not have fuel for it in maybe 15 years.

[Rumrace]

Just to stir the pot have you considered hydrogen. We’re you aware that is the direction Yanmar and Yamaha are going.
Yanmar has a 3 cylinder and it’s not a cast slug either. I saw a tiny hydrogen generator. Doesn’t produce liquid hydrogen just pure gas but adequate for fuel apparently. So honestly I see combustion engines continuing. The groups famous fact checkers will pull up all kinds of old assumptions but Hydrogen is happening and progress from Toyota is astounding

[Adelie]

Originally Posted by Rumrace

Just to stir the pot have you considered hydrogen. We’re you aware that is the direction Yanmar and Yamaha are going.
Yanmar has a 3 cylinder and it’s not a cast slug either. I saw a tiny hydrogen generator. Doesn’t produce liquid hydrogen just pure gas but adequate for fuel apparently. So honestly I see combustion engines continuing. The groups famous fact checkers will pull up all kinds of old assumptions but Hydrogen is happening and progress from Toyota is astounding

Weight and volume issue related to storage mean that hydrogen used in a fuel cell is only slightly better than LiFePo batteries with regards to energy density (MJ/l) and specific energy (MJ/kg). For H2-ICE the numbers would be significantly worse, like comparable to Lead Acid batteries.


Power efficiency (energy out as a percentage of energy in) is way lower 25-30% for H2-ICE vs 50% for fuel cell vs 90-93% for LiFePo vs 87-90% for lead acid.

[Rumrace]

I have one of the first 10 100 cell Tesla’s delivered to Canada. I ordered a 90 but they made two advancements from my order to my 11 month delivery. Was like ordering a yacht
The second advancement was the motor improvement on heat management

In Japan every single manufacturer is focused on Hydrogen. The Yamaha Toyota 450HP Hydrogen Engine is an old block they made for trucks. Mankind will not give up their gas combustion engines.
The first hydrogen producing boxes are pretty lame but so were the first solar panels.
The Toyota little 30’ Cruiser is a doll and flying around on a Yanmar I6 hydrogen.

When LED commercial lighting became viable they required drivers and still do. We adapted pseudo drivers right on the diode board to emulate a driver. It’s why we have 12 V LEDs but few have same light level or CRI. We saved the infrastructure of billions of lighting fixtures. It’s transitional yup
So produce hydrogen on board is not far off. As close as manufactures using better quality electric motors instead of surplus

[Rumrace]

Vroom. They also have a V10 block of Lexus now a Hydrogen Engine.
They raced a 3 cylinder in a car race.
https://www.topgear.com/car-news/future-tech/toyota-and-yamaha-are-developing-hydrogen-fuelled-v8?amp=1

[seandepagnier]

Originally Posted by pete c

I told him a 10kw 48v bldc motor is adequate. Actually, I believe it may be a little overkill. He seems to think it isn't enough. He even told me, his 18hp westy isn't really enough when trying to get home into a stiff headwind.

It is he who isnt enough.

If he thinks you are supposed to motor against stiff winds, you might need to re-educate him before he uses electric propulsion.

As for comparing kw and power to diesel. It is like comparing apples to oranges. Not a very meaningful comparison. Diesel inboards generally spin tiny props. Propeller efficiency alone on most cruising boats is below 30% which is really something pathetic.

You dont want to multiply this number against your 95% efficient battery, 90% efficient motor, 95% controller. You need a propeller that is at least 80%. For a 27ft boat, this prop will be at least 40 inches in diameter. Look at carbon paramotor props.

First off, I am pretty sure he has an 11hp motor unless a previous owner did an upgrade and from what reading I have done on the subject, it seems the 3hp/ton is the general rule.

Its not, there are no "general rules" My boat is 3 tons and using 1/6th hp (120 watts) 2 knots. I'm rigging it up again to achieve 3-3.25 knots at 300 watts.

at 27ft boat could achieve 4 knots using ~ 1hp. (this is all assuming flat calm) Keep in mind, that a single horse (1hp) can pull much larger boat than this all day at 3-4 knots. So while you can't achieve the efficiency of a tow rope, getting 80% will give you easily 4 knots at 1hp (745 watts) and in fact its possible to do much better.

Talking about 10kw and so forth is a bit nonsensical. Yes: you can put rockets on a bicycle, and it goes really fast too!

[Rumrace]

Yup not like he’s replacing a 40 and it’s no bass boat trolling motor.
I’m pretty sure we will see than little Merc electric outboard out there this season.
Cigarettes 64mph 3 hour run time PWC is due in Julyish
Two companies are producing Tesla water generators. One is using compressed air to spin the discs and tiny 150watts. The other is using water as Tesla did in 1909. Toyota’s big Tri hull apparently has several experiments not just hydrogen but solar and water generators.

[pete c]

Originally Posted by Adelie

What you are discussing is a parallel hybrid system. All the design work currently is for serial hybrid systems which suffer from significant efficiency losses.

The EU did research on this and determined that parallel had a bunch of advantages generally. https://cordis.europa.eu/project/id/233718/reporting

Betamarine has parallel hybrid systems for retrofit.

James Baldwin of AtomVoyages has retrofit at least one parallel system with the diesel replaced with an electric motor and a high thrust outboard installed at the stern in the outboard-inboard motorwell system he developed.

I am a huge fan of Atomvoyager. He does amazing work and he is 100% right about using outboards that are protected from the elements but can be retracted when a sailboat is doing what it is meant to do....sail.

I also think that electric outboard that can be swung up out of the water are coming. The beauty of an electric motor is that it like high torque, low speed applications. This means you can use a very efficient very big prop, since prop drag is not an issue when the prop is out of the water. Also, when you have wind power to save, leave that big prop in the water and generate mass quantities of electrons to store for later use. Add the ability to steer this outboard and you could turn that old full keel tub into a marina gymnast.