Star-Lord, Electric Trawler Conversion

Ski in NC said:

You miight want to get some ballast down there in the bilge!! Stability is in question with all that weight pulled out. How dicey stability is impossible to tell over the net. Get some weight down low and leave it there until you start adding batteries. They make good ballast.

Any factory ballast in the keel/bilge?

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It looks very unstable to me as it sits.

There is no factory ballast in the keel. The keel is completely open access so I could fill it with whatever.

I think I will fill the fuel tank with water today and see how that lowers the water line. The tank is molded down low in the keel. 300 gallons should make a difference.

with water ballast

I filled the fuel tank (300gallons) with water to provide some ballast.
It is still sitting high but hopefully good enough for now.

You can see the change in the water line on the bow thruster tunnel before and after I filled the tank.

I plan to tow it 20miles across Tampa Bay to my dock this weekend.

Any new updates?

All I can say is WOW!!! I just read all 183 posts. At around 150 I was going to jump in and strongly urge you to go with a single engine, then you made the decision on your own, good call. Then I was going to ask how you intended to keep motivated. ( I have a Corvette torn apart in my garage that I have not touched in 5 years) You are not only motivated but talented. Great Job so far.
IMHO you are now getting to the interesting part of your conversion. Sort of done with cleaning and grinding and demolishing.

I don't have any advice or criticism . Just wanted to say Great Job so Far!!

When do we get another walking tour?

pete

Any updates? How’s the progress coming?

Good luck with the continuation of this interesting project! I'm especially interested to see how you will be able to fit 15 x 300w panels on this boat. Will you have solar decks? (just kidding).

Updates

This was a great read. I'd love to see if you've made any progress.

twistedtree said:

Sounds like a fun project. I look forward to following. And once you are done and running for a while, I’ll be interested to hear where and how you see an electric boat like this fitting in the market. What sort of usage is practical and/or advantageous for electric

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"Fit in" to what? Its his personal boat. And do you know about maintenance and longevity of electric motors compared to diesel?

David Ess said:

"Fit in" to what? Its his personal boat. And do you know about maintenance and longevity of electric motors compared to diesel?

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My, did Santa leave you coal to make you so grumpy?

I think the answer to your question is right in your quote from my post. I’m interested in his thoughts about how electric boats fit into the market for boats in general.

“Just because I want to do it” is all the reason anyone needs to do something personally.

And yes, I think I have a pretty good handle on the maintenance differences, including battery maintenance and longevity depending on battery technology.

twistedtree said:

My, did Santa leave you coal to make you so grumpy?

I think the answer to your question is right in your quote from my post. I’m interested in his thoughts about how electric boats fit into the market for boats in general.

“Just because I want to do it” is all the reason anyone needs to do something personally.

And yes, I think I have a pretty good handle on the maintenance differences, including battery maintenance and longevity depending on battery technology.

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A good handle indeed. Many thanks again TT for tips on running dual Balmars in series off a single engine.

BTW - quite the story about your boat delivery. Must have been a shock to go inside. Boats can be quite a peak and valley emotional ride

Happy holidays.

Peter

twistedtree said:

My, did Santa leave you coal to make you so grumpy?

I think the answer to your question is right in your quote from my post. I’m interested in his thoughts about how electric boats fit into the market for boats in general.

“Just because I want to do it” is all the reason anyone needs to do something personally.

And yes, I think I have a pretty good handle on the maintenance differences, including battery maintenance and longevity depending on battery technology.

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The maintenace issue means at least one builder offers a lifetime warranty on the electric propulsion motors , and I think 8 on the litium ion batteries, and 25 years for the solar panels. I think they said the motor might need a new bering after 50,000 hours.

We keep seeing more and more electric and hybrid boads.

Bravo! When I got to the point where you converted to single screw, you pretty much nailed how Gulfstar did it on the motorsailer version of that boat. If you need any references for rudder size, look to the old GS motorsailers.

Nice job none the less and it makes me wish I had more motivation and time. I've been spending it all on my old mustang.

You the man star-lord! Nothing but enthusiasm for your project thanks for sharing it is so groot!

electric conversions

twistedtree said:

BoatDiesel.com has some calculators that you might find helpful. I played around with a 40' waterline displacement boat weighing 40,000 lbs. I'm thinking that should be pretty close to what you have. 8.5kw at the flywheel will drive the boat 4.4 kts. 100kWh will last for about 11 hrs allowing for a very small conversion loss (probably too small), so range should be 45-50 nm.


Solar recharge at 4.5kw will take about 23 hrs of full sun and full output. With a typical 5hrs of full sun equivalent available per day from solar panels, you are looking around 5 days to recharge before you can go another 45-50 nm. And that assumes no house electric loads, which of course won't be the case.


You could of course run the generator to recharge and/or power the electric drive, but that will always consume more fuel than direct diesel power.


You might want to run some of these numbers to characterize what the boat will do. It's all pretty predictable. Now I'm a firm believe that "because I want to". or "because it will be fun" is all the reason anyone needs to take on a project. Practicality doesn't have to factor into it. Heck, that's sort of the definition of boating, isn't it? But I think it's always good to have an idea what you might expect as an outcome.

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Has anyone researched the methane fuel cells? basically one cell would provide enough electricity for an Atlantic crossing and back. being utilized in the big ships.

I am currently researching on converting my diesel to electric with a battery bank ballast and a methanol fuel cell, it is roughly the size of a full sized refrigerator. If anyone has any knowledge on them, I would be eager to absorb and learn

Greetings,
Welcome aboard. The ONLY thing I know about fuel cells is the name Ballard. Nice project.


https://www.ballard.com/

Efoy makes small fuel cells that can be “stacked” to make a larger output.

Methanol availablity on the east coast is limited though.

This could be a good alternative to keeping the batteries up when it rains for three days, or where you can’t fit solar panels.

But are not designed to be high output, so no boat HVAC or hot water that a gender provides

https://www.my-efoy.com/en/

Star-Lord said:

I filled the fuel tank (300gallons) with water to provide some ballast.
It is still sitting high but hopefully good enough for now.

You can see the change in the water line on the bow thruster tunnel before and after I filled the tank.

I plan to tow it 20miles across Tampa Bay to my dock this weekend.

View attachment 96855

View attachment 96854

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Any new updates Star-Lord?

R0dger said:

Has anyone researched the methane fuel cells? basically one cell would provide enough electricity for an Atlantic crossing and back. being utilized in the big ships.

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Understand the difference between methane (a gas) and methanol (a liquid). Methane (CH4) is a carbon atom bonded to four hydrogen atoms. Methanol (C3HOH) puts an oxygen atom between one of the hydrogen atoms and the carbon atom. It’s an alcohol, though don’t drink it.

Using either one with a fuel cell requires reformation of the fuel into its component parts to free up the hydrogen, which will ultimately be bound with atmospheric oxygen to form water. If I understand the process correctly, the OH portion of the methanol breaks off by itself and doesn’t get processed in the fuel cell, so you’re only getting 3H out of one methanol atom, as well as one C, which combines with atmospheric oxygen to create CO2. The methane process is simpler, with all four hydrogen atoms being used up in the fuel cell and the carbon atom going off to merrily form CO2.

The problem here is that the reformer takes energy to run, cutting into the efficiency. There are some “DMFC” (direct methanol fuel cell) systems that bypass the need for a reformer, but they’re horribly inefficient, with much of the energy going to waste heat.

Any hydrocarbon fuel (methane, gasoline, diesel, ethanol, methanol, etc.) is an energy store. The trouble is getting the energy out without polluting the planet, which is what burning it directly with atmospheric oxygen does. Reforming any of them into free hydrogen and carbon, then running the hydrogen through a fuel cell, is “inefficient” in terms of the long chain of processes necessary to get to useful energy, but it’s still MORE EFFICIENT than straight up burning it in an internal combustion engine.

And now I’ve entirely exhausted my ability to speak on this subject.

Hope this helps.

JD

I’m new here, so hi all! Seems this thread has gone cold. Any updates on the project? I would be very interested. I’m toying with the idea of converting a 1971 Grand Banks 32 sedan to electric, intending to mostly cruise up and down the St John’s river in Florida.

Why? Are the engines non operational?

tiltrider1 said:

Why? Are the engines non operational?

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The engine is fine, it's personal preference. I just like electric over IC. I work from home so if I travel at maybe 5-7 knots for a few miles every 2-3 days staying protected in the St. Johns river most of the time, my energy consumption might be fairly low. So that with some modern solar panels and a couple mini vertical wind turbines, I could maybe stretch out boondocking a little longer while slowly running down a couple of Tesla battery banks, before inevitably needing to pull in somewhere to top off with shore power and empty my holding tank. I'd like to keep the classic wood hull but update most everything else such as adding a tankless water heater, induction cook top, mini washer/dryer combo, chest freezer, bow & stern thrusters, ect. My goal is to get off of diesel and propane all together so that everything runs off the same power source. There may be some fatal flaws in the plan and it's definitely not going to be a good return on the investment but I am encouraged to see that others have had similar ideas. Anyhow, I'm quite a ways from pulling the trigger and am still in the researching phase for now so any thoughts or obstacles anyone might be able to point out are definitely welcomed.

It will take 100hp to push that boat 7kts. You might look for something more efficient like what StarLord started with.

Actually, I calculate about 35hp needed at 7 knots. Since OP is focusing on the river and likely intercostal cruising, there would be minimal wind resistance. So that's an electric motor of 26kW.

My wife and I love cruising the St Johns. That and no-wake zones around Ponce Inlet, we would spend hours at 5 knots. I like his idea, especially if this is just a fun project.

Figure you need about 4 hours duration which would translate to a 125kW-hr battery pack of (preferred) LiFePO batteries versus Tesla packs (Li-Ion). You'll never charge via a few solar panels, that's silly, but some panels would make you feel better for sure.

Slow down to 6knots and your range extends greatly.

Find a cheap enough GB32 with a crappy old engine and go for it!

Thanks for the responses!,

The GB has a 120hp diesel and I know there are couple manufactures that make 100hp electric inboard motors but I think I would be pretty content to chug along at 5 knots so maybe I could get away with less. I don't plan to get out into any big water so the river and Ponce Inlet seem perfect. I would also be open to other hull designs but the GB caught my eye. I have seen a 30ft Sundowner Tug though that looked good and runs a 75hp diesel so there may be some better options out there if I look around more. I'd like to keep it around 30 to 35ft. Main trick is finding one with a crap engine! All of the ones I have found so far have been immaculately maintained and the thought of pulling the engine out is painful but I'm hoping I could sell it for more than it costs to have it removed haha. I'll check out the LiFePO batteries and agree the solar and wind trickle won't charge enough for the propulsion consumption but it should help out with ancillary use on things like cooking and electronics so I can reserve most of the battery for the motor.

So back when I was living in Florida (Space Coast) my wife and I had similar plans, but for day trips so I was going to repower a small 22ft boat. I don't recall alot of specifics but it was obvious that it would need a 96v battery pack. Prices sourced directly from China were reasonable but it was still $10k-12k. There are many reputable companies you can go to but it takes research. Try Alibaba and MadeInChina to begin with.

BTW, in Florida you will find all sorts of crappy Taiwan trawlers for sale, fiberglass, that you can pick up for about $40k. Even as large as 40 feet. Mainship 34's for about $30k. They are everywhere. Don't get hung up on a Grand Banks. You're doing this for fun but your recovery will be next to nothing - it's all sunk cost.

Once you settle on your speed, range and resulting battery capacity, run the numbers on how long it will take to recharge off available dock power.

Mako said:

So back when I was living in Florida (Space Coast) my wife and I had similar plans, but for day trips so I was going to repower a small 22ft boat. I don't recall alot of specifics but it was obvious that it would need a 96v battery pack. Prices sourced directly from China were reasonable but it was still $10k-12k. There are many reputable companies you can go to but it takes research. Try Alibaba and MadeInChina to begin with.

BTW, in Florida you will find all sorts of crappy Taiwan trawlers for sale, fiberglass, that you can pick up for about $40k. Even as large as 40 feet. Mainship 34's for about $30k. They are everywhere. Don't get hung up on a Grand Banks. You're doing this for fun but your recovery will be next to nothing - it's all sunk cost.

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Good to hear, I'll do some digging, I'd like to keep cost of the boat low since I want to gut and replace a lot. Plus as you said, pretty much the entire project cost will be sunk. The process and end result is for my enjoyment but I doubt it will have much resale appeal haha.

twistedtree said:

Once you settle on your speed, range and resulting battery capacity, run the numbers on how long it will take to recharge off available dock power.

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Definitely a good consideration!, consumption rate and range are always top of mind but recharge rate is going to be a big factor. I doubt I'll find any level 3 fast chargers! If shore power is typically 120v it could take a while to top off and might run up the daily operational cost significantly.

Good point thanks!

It's too bad that the OPs project seems to have fizzled.

ModernMuk said:

Definitely a good consideration!, consumption rate and range are always top of mind but recharge rate is going to be a big factor. I doubt I'll find any level 3 fast chargers! If shore power is typically 120v it could take a while to top off and might run up the daily operational cost significantly.

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If you're able to dock at a berth with 50A 125/250v service, you'll be able to do a full Level 2 charge. If you're running a single EV's worth of battery cells, regardless of chemistry, you'll be able to get that charged overnight, probably faster. If you're running more battery than that, then up your time by the same percent more battery you have.

If you're in a berth with 30A, 120v service, your charge time will be significantly longer (think 13+ hours for single car's worth of battery cells.

Like you and the OP, I've been thinking about what it would take to convert an existing trawler to electric for some time. As much as I'd love to dive into a 100% electric build, I don't think the technology or infrastructure is there to build an affordable battery electric propulsion system without compromises I'm unwilling to make, such as committing to 5-7 knot cruising.

What I think will work, and will provide a lot of the benefits of a 100% electric system, is a series hybrid diesel electric. If you run an 80 kWh battery (ie Tesla Model S long range) with a repurposed EV motor (150-300hp), you could have both good cruise range and the ability to motor out of tight situations at higher speeds. But you'd be dead in the water if you needed to use more power more frequently, so I wouldn't be comfortable with that trade off. Hence the addition of a diesel engine, perhaps fitted roughly where and how the factory diesel was, but spinning a genset instead of the prop. That genset would be charging the battery pack and running at max efficiency, since it'd be under consistent loading. Of course, the diesel could be off on slow cruise days, so you're running silently. Plus, dropping anchor with a full battery means you can run air conditioning all night without the thrum of a genset, cook with induction, and even heat with electricity, which means no propane on board either.

Truth be told, none of this is probably going to happen for me...at a certain point, the price/performance ratio of a hybrid or even full EV cruiser will drop to where I'd as soon buy as build something that's never going to be worth what I paid, let alone what I paid plus what I spent on retrofitting.