“Anyone considering going all electric propulsion in the salty ocean environment is being naive. The IC and computer components will corrode unless sealed circuit board tech, like in military, automotive ECUs and even in residential clothes dryers is used. That makes repair maintenance difficult....unless spare sealed circuit boards can be easily swapped? out.”

Interesting position, and not difficult to agree with the reasoning. ?I’m sorry to hear that your installation has led to many component failures over time due to environmental factors.

But in practice, I have not found this to be a problem. ?I converted my boat in 2009 to ABYC specs, and she has been in the water every day since, excepting haul outs for bottom maintenance. ?Many of my components are EV (land based) spec’ed items, like my Elcon charger, and the only failure that I have had so far was a main contactor that I mounted upside down, in the “catch water” position, because it made the wiring easier for me at the time. ?After the failure, I read the manufacturer’s specs and they clearly stated to not do what I did. ?The new contactor is installed in the correct orientation. ?Funny thing is that the water that did the damage was fresh water runoff from rain, salt water was not a factor. ?Overall, there is minor surface rust on some ferrous components, but nothing that has affected performance or function. ?

Speaking of performance, I am running a pack of 16 LiFePO4 prismatic cells with no BMS other than autonomous “mini-BMS” modules on each cell that do minor top balancing, and have had no noticeable cell drift in 12 years. ?I store the cells at 100% state of charge for months at a time, and the pack still tests out to more than the original 160ah cell spec, but capacity is down about 5% from the initial installation testing.

Much of what I read here sounds like people are over-thinking their designs and solving theoretical problems that may not be as much of an issue as they sound like they could be.

Back to the original comment, after 12 years, the ocean environment has had no significant affect on my electric drive systems. ?I’l let you know if any problems crop up in the next decade or so...

Eric
1964 Cheoy Lee Bermuda 30, Serenity - 5.5kW drive, 8kWh LiFePO4 traction bank
Marina del Rey, CA

On 30 Apr 2021, at 4:46 am, Jeff LaCoursiere <jeff@...> wrote:

? We haven't had any bad cells imported yet, knock wood.? We *are* doing our best to burn down our offices with our BMS experiments though :)? Also, our latest batch was all EVE 280AH cells, the Lishen 272AH are apparently "all gone".

Another cool idea we are kicking around... we want our 48v pack to have a 12v tap, so you can use it as your house battery as well as your traction battery.? I'm disappointed in the available downconverters, mostly current limited to 30-60A.? Maybe that would be enough for your house, but it wouldn't do it for mine.

On May 1, 2021, at 05:48, Bob Jennings <heatnh@...> wrote:

?

Gotta admit you guys are definitely pushing the edge of the envelope & taking EP in a direction that to me is mindboggling.? Nice work!

On Sat, May 1, 2021, 8:25 AM Jeff LaCoursiere <jeff@...> wrote:

Oof, that thing costs more than the cells to make the pack. Looks like a nice unit though!

Regarding all the issues pointed out about our fast switching bank idea, all completely correct - noise, power draw, may be a completely impractical idea.? Will let you know how it turns out :)

Cheers,

j

On 5/1/21 2:40 AM, Robert McArthur wrote:

Jeff, have a search for Safiery and their Scotty product. It’s a 2-way DC-DC 12-48 buck boost for 3kW. It would provide your 12v tap (up to 3kW).

On 30 Apr 2021, at 4:46 am, Jeff LaCoursiere <jeff@...> wrote:

? We haven't had any bad cells imported yet, knock wood.? We *are* doing our best to burn down our offices with our BMS experiments though :)? Also, our latest batch was all EVE 280AH cells, the Lishen 272AH are apparently "all gone".

Another cool idea we are kicking around... we want our 48v pack to have a 12v tap, so you can use it as your house battery as well as your traction battery.? I'm disappointed in the available downconverters, mostly current limited to 30-60A.? Maybe that would be enough for your house, but it wouldn't do it for mine.

--

	Jeff LaCoursiere STRATUSTALK, INC. / CTO Phone: +1 703.496.4990 x108 Mobile: +1 815.546.6599 Email: jeff@... Website: Address: One Freedom Square 13th Floor Reston, VA 20190
	? ? ?

--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI

From: [email protected] [mailto:[email protected]] On Behalf Of Eric via groups.io
Sent: Saturday, May 1, 2021 8:16 AM
To: [email protected]
Subject: Re: [electricboats] Draft Schematic-Please give input

?

“?I was specifically referring to over computerized systems on smaller boats, susceptible to humid, salty atmosphere. . If the installation is kept more rudimentary and simpler, it can assumed it probably would be less troublesome. Larger vessels that have extensive electronics, have more climate control and hardened electronics”

I still can’t tell where you’re going with this. ?My all electric propulsion boat (PMAC motor, 3phase AC controller, advanced SOC monitoring, smart charger, etc.) has sophisticated electronics, not hardened, with no climate control in a 57 year old wooden boat. ?After 12 years in the ocean, no component has failed due to the humid, salty environment. ?You have already stated that that I am being naive for the conversion of my ocean going boat, are you also implying that my highly efficient and effective conversion is rudimentary? ?Please tell us which electronic components in your boat have failed due to environmental exposure so that we can take the appropriate precautions.

Eric?
Marina del Rey, CA

“?I was specifically referring to over computerized systems on smaller boats, susceptible to humid, salty atmosphere. . If the installation is kept more rudimentary and simpler, it can assumed it probably would be less troublesome. Larger vessels that have extensive electronics, have more climate control and hardened electronics”

I still can’t tell where you’re going with this. ?My all electric propulsion boat (PMAC motor, 3phase AC controller, advanced SOC monitoring, smart charger, etc.) has sophisticated electronics, not hardened, with no climate control in a 57 year old wooden boat. ?After 12 years in the ocean, no component has failed due to the humid, salty environment. ?You have already stated that that I am being naive for the conversion of my ocean going boat, are you also implying that my highly efficient and effective conversion is rudimentary? ?Please tell us which electronic components in your boat have failed due to environmental exposure so that we can take the appropriate precautions.

Eric?
Marina del Rey, CA

Eric,
I concur.? Over 600 conversions on ocean going sailboats up to 40000lbs.? If you do it right with quality marine components you will have a safe and reliable system.? Yes you can cross oceans as I am aware of many blue water cruisers with 1000's of open blue water sailing.? Some Volvo Vendee racers have electric propulsion.?

I look at sailboats as compromise and recommend sailors select what is the best for them and their sailing agenda.

I actually do understand purest who do not have any propulsion systems on their sailboats but sails. But there is not a diesel or gas powered sailboat that does absolutely depend on electric motors.? They are the most reliable motors on the boat.? Unless you hand crank the diesels (no electric starter), gravity fed fuel (no electric fuel pump) hand bilge pumps (no electric bilge pumps),? And who does not say a short prayer "Lord please let it start" when you need an emergency start of a diesel.

Just saying,.
Mike? Electric Yacht

“?I have zero electronic components in my boat except portable waterproof radio, plotter and cellphone...”

pv Beveren,

Apparently, you do not have an electric boat, and your 5 posts here since your first post last December have basically suggested that diesel solutions are better, and that implementing an electric drive in an ocean going vessel without spending money like a military or aviation project is bound to fail. ?If you think that the electric boat conversions that are the main topic of this group are a bad idea, I have to assume that you don’t want one. ?If you don’t own one and you don’t want one, why are you here?

Regards,
Eric

Unfortunately, when one wants to do or build something that is not available “off-shelf” ( like the guy that started this thread), one must do the best one can with what is available and do one’s own field testing. ?I did exactly that more than a decade ago, when there were few marine conversions done, and every conversion was experimental. ?We were developing the guidelines and performance predictions that are common knowledge today. Much of what you’ve read on the internet about electric marine conversions is based on the knowledge that was collected and shared here first. ?People like Miles and other pioneers here helped me figure out what might work well in a boat like mine, and collectively, we nailed it. ?

It’s pretty easy to say “ it’ll never fly” from one’s comfy armchair, it’s riskier to invest the time and money to do the work and see what happens. ?I came here to gather what knowledge there was, synthesizing answers where there were none, then took the leap and converted my boat. ?It was no cheaper or easier than repowering with a new diesel, but I ended up with a boat that is more reliable and more enjoyable than it was before. ?My extensive performance testing is well documented in the 1100+ posts that I have made in this group to help those that want to do something similar. ?I honestly have few first hand lessons of what not to do or avoid, but often share what has worked well for me.

It’s easy to see why many other folks are here, I’ve stated why I am here, and my question is still “Why are you here?”

I never said "bound to fail"....the odds are higher the cheaper the parts.....or more innovative and relatively not as field tested system. Reality my friend. Diesel is well proven, bodging together an untested electrical drive? sketchy at best....unless well tested. Aircraft have well defined Hours of Operation maintenance schedules, good parts are yanked out and replaced, well running engines rebuilt....and still planes fail.

On 01/05/2021 7:12 p.m., Eric via groups.io wrote:

"?I have zero electronic components in my boat except portable waterproof radio, plotter and cellphone..."

pv Beveren,

Apparently, you do not have an electric boat, and your 5 posts here since your first post last December have basically suggested that diesel solutions are better, and that implementing an electric drive in an ocean going vessel without spending money like a military or aviation project is bound to fail. ?If you think that the electric boat conversions that are the main topic of this group are a bad idea, I have to assume that you don't want one. ?If you don't own one and you don't want one, why are you here?

Regards,
Eric