Information Overload - Where do I start?:)

RV10flyer said:

Search “the digital mermaid” on YouTube for a lot of information.

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Modular Hippo said:

Big thank you RV10flyer - Nicer to see that I am not the only one out there with crazy dream Will check all episodes in the hope to pick up some do's and don'ts

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digimer said:

Let me know if you have any questions.

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Modular Hippo said:

Hi DigiMer,

I hope all is well.

Only saw this message first now as not logged in since my first post. Boy do I have questions, not even sure where to start

1. Not sure if you have picked a motor yet, if you have then super interested in what motor you decided to get (voltage and kw?)
2. What max amp have you settled at in relation to BMS and cabling? This is where I get a bit confused as the motor I am looking at says 'PEAK CURRENT 400 Amp' but most people I have seen doing conversions have wiring for either 100 or 200 Amps.

Let's start there

Thanks DigMer!

Henrik

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digimer said:

> I guess a pod would make sense as less risk of issues & water coming in via the traditional prop-shaft. Saying that, the pod has its own prod shaft so maybe just swapping one issue for another?

The main two benefits of a pod are lack of through hulls (cooling or prop shaft), and lack of gearing (prop directly on the pod motor's rotor).

> Looking at 'The Neds' videos I do not think he has ever exceeded 100amps as he is operating his vessel. If I understand it correctly his wiring etc. is maxed at 200 amps just in case. He is running a 10 kwh (water-cold) Golden Motor.

I should watch that, but I haven't yet, so I can't speak to it. I've been looking at the torque curve of my diesel and comparing it to what I needed when I brought my boat home. I saw around 2100~2200 rpm with occasional peaks around 2500rpm. This puts me into the ~8.3kg/m torque range. For that, and I might be over-specing I admit, I am aiming for about 15kw to get around there. I'm designing from the battery bank to peak at ~600A, though I highly doubt I'd sit there long.

> I was first set on a 'Lynch' brushed pancake (air/fan cooled) 10kwh motor but after watching the Ned I am now split as heat generated by both motor and motor controller shows a real need for proper cooling. My hope is to use the motor as little as possible (in and out of docking BUT know that in reality it would be used in many different situations so guess needs a safety margin in relation to size of power-bank and length of safe continuous use).

This was my thought originally, too, but I've now changed my mind. The trip home had me motoring for days on end through the rivers and canals. I fully expect to do similar trips in the future, so I am designing for continuous operation now, and assuming head currents in these plans (hence my upgrade to a 15kw or better motor). I can imagine similar needs in the duldrums on a crossing, also.

I'm starting to look at inboards, as I just can not find a good pod option. Given this, and the comment above, I am planning to keep water cooling, reusing the seacock / sea strainer I've already got. Liquid cool the controller and the motor. I've spoken to others who've converted and getting their power derated from overheating is a real concern.

> Interested in your choice of output power - 12-15 kwh. I guess that is based on your boats displacement? The boat I am building will end as an aluminum ( LOA 11m (36') and a displacement of 8000Kg. mono-hull so not 100% sure if 10kwh Brush-less (as in Neds case) would be sufficent. According to Lynch their motor would replace something up to combustion engine 50hp (which in my case would replace a Yanmar 39hp engine).

I'm at a handicap as I'm still working on paper, and I'm focusing on torque ratings at this stage. That said, I have NOT chosen a prop yet, and that will effect things. Also on that topic, I am putting a heavy priority on regen under sail, so my pushing efficiency won't be the greatest as a trade-off.

I've got currently a Yanmar 3GM30 diesel, and I used my ~760 nautical mile trip home (~875 statutory miles / 1400km) as a base for the torque I needed. Given then, and given I'm going to have additional losses if I stay inboard, 15kw is my current minimum size. Fighting currents on the Hudson / Niagara rivers really drove home the need to have solid pushing power. If you plan to be anywhere tidal or potentially need to sail to wind, I think going larger is needed, even if you know that 90% of the time you'll be fine with 5~8kw.

My LOA is 11.5m, LWL is 9.2m with a dry weight of 7,575kg, though my trip home was closer to 8 tonnes, I am sure. She's an efficient hull, double-ender with minimal wake. I was burning an average of 2.2~2.3 liters/hour.

> Anyways, wont bore you with more of my thinking out loud - One step at a time.

Cheers, and sorry for the slow reply.

Madi

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Skypower said:

Do you have a harbor in mind?
In many parts of the states, nice marinas require liability insurance to be birthed there. In order to get insurance most reputable insurance companies require a marine survey. Non reputable insurers are not accepted by some marinas because of their pattern of insurance claim denial due to the boat not meeting Coast Guard regulations(they’re out). A marine survey will have a report of anything that does not meet US Coast Guard regulations or ABYC guidelines, having deficiencies (rot,corrosion, maintenance or safety) a general description of vessel and power type(s) and valuation. If the surveyor doesn’t see an agency approval on a system they’ll likely state it as so.

Insurance may not be an issue if you haul out on trailer(small boat). Also not an issue if you’re keeping the boat on a ball(anchorage) but that limits your ability for shore power to guest/visitors dock with limited means of electricity available and perhaps a premium if the harbor master realizes your energy needs.
Just something to consider beyond an electric boat build and limited solar area. During the time I had a boat in harbors, I knew of several boats that were asked to leave and had to go to a sketchy marina(your boat could get stripped). As a side note. Make friends with other people in harbor especially the “live aboards” they are your eyes and ears. Even so, in a nice marina with cameras, gates and live aboards, I got ripped off 3 separate times but only minor losses.
Not trying to be a buzzkill, but it needs to be known.

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Modular Hippo said:

Hi SkyPower - All really valid points!! Not even thought that far as I am only 25 % through the actual build of the boat. I am in the UK but guess the regulations and culture to be very similar to US so taking all your points onboard I did a solo 360 around the world tour on an old motorcycle between 2014-2016 and the learning curve was steep as I set of with very little research done - trying to be more prepared this time Thanks again for your info!!

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Skypower said:

It’s amazing how rules and regulations vary across the US. I had visitors from the UK and they were in shock with our laws and regulations. A phrase that is rarely used here anymore is “Well, it’s a free country”.
My boat was 43 feet long with 640 worth of horsepower. Efficient it was NOT, but it was a heck of a lot of fun at speed as long as you could keep the gallons to the mile out of your mind.

View attachment 161806View attachment 161807View attachment 161808

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Skypower said:

Do you have a harbor in mind?
In many parts of the states, nice marinas require liability insurance to be birthed there. In order to get insurance most reputable insurance companies require a marine survey. Non reputable insurers are not accepted by some marinas because of their pattern of insurance claim denial due to the boat not meeting Coast Guard regulations(they’re out). A marine survey will have a report of anything that does not meet US Coast Guard regulations or ABYC guidelines, having deficiencies (rot,corrosion, maintenance or safety) a general description of vessel and power type(s) and valuation. If the surveyor doesn’t see an agency approval on a system they’ll likely state it as so.

Insurance may not be an issue if you haul out on trailer(small boat). Also not an issue if you’re keeping the boat on a ball(anchorage) but that limits your ability for shore power to guest/visitors dock with limited means of electricity available and perhaps a premium if the harbor master realizes your energy needs.
Just something to consider beyond an electric boat build and limited solar area. During the time I had a boat in harbors, I knew of several boats that were asked to leave and had to go to a sketchy marina(your boat could get stripped). As a side note. Make friends with other people in harbor especially the “live aboards” they are your eyes and ears. Even so, in a nice marina with cameras, gates and live aboards, I got ripped off 3 separate times but only minor losses.
Not trying to be a buzzkill, but it needs to be known.

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Modular Hippo said:

Hi DM,

Big thank you for your thoughts and feedback on my points as much appreciated!! Our vessels sound very similar in characteristics (displacement etc.) which is handy for comparing notes in the future If you get to watch The Neds you will find a water cooling solution that s very basic but seems to work fine. A heat sink cooled by water that in turn is cooled by 3 small 12V industrial fans. He has a closed system for the controller and separate closed system for the motor. The concepts is used in gaming computers so seems to be robust enough if you find the correct components. Gearing is an interesting subject as well as found that some with inboards have decided not to gear, and others have started of with gearing and wish they did not and eventually removed gearing and swapped to direct drive. Onward and Upwards! Thanks again!

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digimer said:

I'm in St. Catherine's for the refit, and I have insurance with liability (twice what's needed, just to be safe). I'm already working with a broker to find post-conversion insurance, and I'm being very careful to follow and meet (or exceed) all ABYC standards, specifically to ensure my own safety, and the ability to get insurance.

This is a good question though, sailboat insurance is not a simple "call, pay, get" thing. It requires careful thought and consideration, annoyingly.

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Skypower said:

It was a wonderful boat and the cat and I had made thousands of memories. View attachment 161826When he passed away it was the last reason to not have the boat, fuel was the other reason. I knew that as long as I owned it the boat would go out every weekend which means $$. It was fully functional unlike most other boats in the harbor. Everything worked because it was maintained which means more $$. Unfortunately the guy I sold it to didn’t maintain it and I was in shock how far it had gone bad in four years. He sold it and I have lost track of it. Hopefully the new owners will get her back to the way I had it but it’ll cost serious money.

If I had to do it again, I would have gone a different route but still a houseboat but much bigger and slower. It would also not have any wood as part of its structure. My boat was fiberglass but it used wood as structure within the glass of which most had to be replaced at great physical expense. Wood does what nature intends, it rots. All the steel boats I’ve seen were again too much work, but the aluminum boats that had proper galvanic protection were in excellent condition. Several times I got a call from a friends that had engine trouble (bad fuel) and wanted to know if I could come and bring them back to harbor. There’s no way I’d try to do this with my big boat because once in harbor there’s no room for both safely. So I used my little RIB with a 20hp Suzuki outboard. Right before I towed (side tied) I swapped to the spare prop that I found at a garage sale. The prop was totally wrong for normal use( big diameter and shallow pitch) but perfect for this. It was then I discovered how a small engined boat can move 40 foot cruiser at a pretty good clip even when off thrust line. Imagine a how fast it could move a displacement hull (double ender/canoe) instead of a planing hull. So this got me to thinking, aluminum hull(s) and houseboat and big. A 65’x14’ or 70’x16’ Fun Country houseboat. Like this: View attachment 161829
Some of these during a certain period had a mold issue from a manufacturing problem, if you know where to look to find it. Some had twin i/o drives and those are just easier to delete with outboards(or convert). One of these boats could be converted to electric and the entire upper deck could be shaded with welded aluminum structure holding panels for the entire length and width of the boat. Electric propulsion and thrusters could probably be good for 8 to 10 miles a day with good charge and little headwind while still maintaining amenities, If not wait till it is, no rush in retirement. HVAC could be provided with MarinAir water to air heat pumps. I had one in the boat I had and it was so quiet. Water temperature here is cooler than air in summer and warmer than air in winter so you’re already that much more efficient with that type of heat pump. Could also go mini splits but the outside unit would make noise. When you’re on the river, silence Paramont. Holding tanks could be done away with by using incinerator toilets and having plenty of solar power that wouldn’t be a problem. The boat could use the freshwater around it to make potable water with filtration and UV treatment. Pretty much all the conveniences at home. Fresh meat is as close as a hook over side. I’m done with California and I know they have these boats in the Tennessee area too. I’m not sure if I want land or water under my feet. What ever I do, I don’t want to be a slave to it.

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digimer said:

I'm in St. Catherine's for the refit, and I have insurance with liability (twice what's needed, just to be safe). I'm already working with a broker to find post-conversion insurance, and I'm being very careful to follow and meet (or exceed) all ABYC standards, specifically to ensure my own safety, and the ability to get insurance.

This is a good question though, sailboat insurance is not a simple "call, pay, get" thing. It requires careful thought and consideration, annoyingly.

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digimer said:

I do watch the Neds, he's very close to me. I've been meaning to reach out to them and see if they'd like to meet up. Perhaps eventually.

I am leaning heavily towards keeping the old 3/4" engine cooling seacock and heat exchanger, and using that to actively cool my motor and controller. I was speaking the Allure Arctic and they also mentioned that cooling is their big issue, and they're running Ocean Volt kit. So as much as I like the appeal of air-cooled simplicity, it seems like active cooling is the way to go.

Neds uses a modified PC water cooling radiator, iirc, and that would rely on fresh air coming from somewhere. I can see that being a problem, hence leaning towards water cooling.

As for gearing; I'm really leaning to two parallel motors, and using belt drive to the prop shaft. That will let me use simple pulley sizes to set my gear ratio, and avoid metal teeth of teeth gearing.

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Modular Hippo said:

Ha Ha - I see a clear link between Cats and crazy boat projects..... I have two cats myself and convinced that I 'speak' cat (from the outside I probably just look a crazy cat-man) If I understand it correctly the Digital Mermaid also gets allot of help in her build by her cat/s. Before I decided on building in Aluminum I did allot of research and all other materials scared me in one way or another (either from a maintenance effort point of view, or just unknowns I could not 100% control such as osmosis etc.). The curves and soft lines you can achieve with wood/glass is obviously a huge advantage but luckily I have personally always favored practicality over aesthetics so no loss on my side in that area Wow - A 65’x14’ or 70’x16’ house boat of that style, that is what I call a house boat!! And as you say, no lack of space to put your solar panels!! Go for it!!

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Skypower said:

At one point I had 3 cats(in the boat) and one harbor cat. The harbor cat was my guard cat and kept the males away from marking my boat when I was gone. She was well rewarded. She didn’t keep one female from having kittens in my flybridge! One of my 3 convinced me that she’d rather stay home and not go boating. That left Alex(orange) and Bob. Bob made it to 24 and Alex 13. Bob was super chill with anything and Alex was more like my shadow, very much with a personality of a smart dog. When we got to the islands he had free rein as long as no one had dogs.
View attachment 162726

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Modular Hippo said:

Fantastic!! Cat's are such good company, we are of course only their humble servants (we all know that) but still the best!! Alex looks well cool, amazing how they always manage to jump up on the stool you are about to sit down on only seconds before you intend to use it (as if they know in advance, ha ha).

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Skypower said:

Exactly lol! He’d jump in the chair and look so satisfied with his eyes saying “Nice chair, where are you gonna sit?” So the next day I went to COSTCO and bought a second one (because they never carry anything you like very long). Next weekend I put both chairs down. He hopped in one and then the other. Funny to see the look of confusion and frustration as I wrecked his game.

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