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 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

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

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

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.

“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 19:53, Ryan Sweet <ryan@...> wrote:

?

I guess that’s my point is if the system is capable of 96v its a different thing and should be treated as such. ?IIUC, Morris like the me1515 etc are most efficient at the higher end of their voltage range. I think the reason most of us want to keep things at 48v is that the simplicity of the system and the cost of the batteries makes it worth the efficiency trade off and lower max power.?

On Apr 30, 2021, at 11:46, Jeff LaCoursiere <jeff@...> wrote:

? Above 50v there are safety considerations that most DIY folks aren't ready or willing to entertain...? I think even some regulations? Anyone know more about that?

Cheers,

Jeff LaCoursiere
s/v Angels Quest

On 4/30/21 1:42 PM, Ryan Sweet wrote:

The other thing about 48v vs 96v is really why not just run at 96v the whole time. Basically if you are making it possible then all the rest of the system has to be specd to 96v and I don’t see the reason to not keep it that way??

On Apr 30, 2021, at 11:12, Ryan Sweet via groups.io <ryan@...> wrote:

?

On Apr 30, 2021, at 9:38 AM, Carsten via <Carstensemail@...> wrote:

Another thing, how about making the motor wattage output adjustable, so it is possible to use eg. 96V for a burst mode ? Many 48V motors can be powered by 96V (or higher).

I assume that the wiring can handle that. Making two sets of banks 48V, to be serial connected to 96V.

The short "event" should of course be managed by the BMS/power management system.

This is interesting and something Ive wondered about but from what I’ve been able to discern it requires dynamically reprogramming the motor controller. ?You could imagine a switching setup that let you have 48v traction banks in parallel but then to change them to series. ?I wasn’t able to figure out a way to use the Seven Gen4 to do this kind of thing, at least from reading the manual. ?I fear I am about to venture into the world of the DVT software though and maybe its capable of that. I suppose if a person spent enough on controllers and cables you could have a dual system with two controllers and switch between them but I think you approach the point of diminishing returns.?

However, it points to a possible opportunity or maybe just a future feature that advanced motor controllers will enable. ?With EV regen becoming more popular in controllers, I would not be surprised if some battery management features also start to migrate to controllers as well.?

To be true, things made in China is not my cup of tea, but in these days, unfortunately simply unavoidable !

I was a supervisor in China for several years, and know how they make things, and all of QC is not like in the West.

Buy a ME1616 electromotor. Made in China, then sold in the West.

Buy yourself a german or US car. Half of the smaller parts in it are made in China by now.

Company supervisors are not in China now, because of the Made in China virus.

Who wants to spend 2-4 weeks in quarantine to go for an inspection ??

Who's checking the quality now ?

As I spin up my own commercial efforts I have been working with colleagues in CN to understand the quality dynamics and the manufacturing landscape and while I think some of these comments are in a general sense applicable, I think that the demands of growing sophistication in their domestic market, growing domestic regulatory regime, and a drive to differentiate by rising to the QC and supply chain standards of Korea, Japan, US, and Europe is pressuring a lot of CN companies to advance. ?I think now it is more a story of doing homework to understand your partners and their processes.

Now, the current chaos of the global shipping / logistics is another story! The Suez Canal incident has cost me several weeks and the knock-on effects will continue for months.?

However, I believe that new, checked, LiFePO4 batteries will last my sailing life out, but the electronics is another concern.

Especially in a marine environment (humid and salty).

Can you provide recommendations where to setup these (rather large) electronic regulators/inverters/BMS'es in the boat ?

I guess IP rating is not relevant, if not encapsuled in IP-rated boxes.

If put into boxes, then there's a cooling issue...

As far from any wet bilge or dripping shaft or outdoor moisture as possible. ?In the cabin if you can. If exposed to moist air frequently try running some electric air warmer/dryers or a dehumidifier (when on shore power).?

Working hard on the ultimate solution for my own EMS/Y system conversion design.

Cheers, guys

Carsten

Hint : EMS/Y = Electric Motor Sailing Yacht ;-)

On Friday, 30 April 2021, 02:46:25 GMT+8, 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.

So we want to try to cycle through internal banks of four cells, very quickly (like 10khz), connecting them in turn to the 12v tap.? We believe that this way you will be able to pull the full 1C discharge of the 16 cell pack (280A), but at 12v!? We hope to maintain balance in discharge by cycling very fast, but the BMS should pick up the slack.

Cheers,

Jeff LaCoursiere
s/v Angels Quest

On 4/29/21 11:34 AM, Carsten via wrote:

Hi, Jeff

Did you experience single/multiple cell dropouts from Lishen batteries so far ?

On Thursday, 29 April 2021, 23:22:13 GMT+8, Jeff LaCoursiere <jeff@...> wrote:

I wanted to comment on 1) below - we have that same concept in mind.? We are working on a BMS design that will basically allow cells to be "dropped out" of series, the output run through a boost circuit to maintain steady voltage.? There are of course limits to how many can drop out and we are very much at the experimental stage here, but there is some hope :)

Jeff LaCoursiere

s/v Angels Quest

On 4/29/21 10:06 AM, oreillygb@... wrote:

First Draft of Schematic. Using Lishen 202Ah. I decided to go with the BMS only actively controlling the charge side of the circuit and opted for passive monitoring on the load side. Using a victron 712 for monitoring and hopefully can connect it to a relay to shut off charge circuit at predetermined voltage. Guys please tell me what I have missed.

Couple of points.

1) Passive Load monitoring. I have decided to go this route as i understand that the load BMS can turn off for 2 reasons, obviously first is if whole bank drops to a lower than 20%SOC and secondly if single cells fail. From my perspective if I have a single cell failure I would rather still be able to use the other 15 cells than have no power. If I let my bank drop to below SOC of 20% that's?on me.
2) Want to keep house bank separate?for now, mainly as if I have to shut off my 48v bank for low SOC I don't want to have to worry about all my electronics being offline.
3) I want a separate?relay to shut off charge current so that I can set this manually. When I come back from a sail i want to be able to top bank up to about a 70% SOC for storage. Then on the day I want to sail I can top it off o 90%

-- 
Jeff LaCoursiere
StratusTalk, Inc.
703 496 4990 x108
815 546 6599 cell

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

--

	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

--

	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