On Jun 1, 2023, at 20:16, Robert McArthur <rjmcarthur@...> wrote:

?

Thanks Dan. You're a trove of good information!

Have you had any issues with the ME1616?

On Fri, Jun 2, 2023 at 2:17?AM Dan Pfeiffer <dan@...> wrote:

I have not built the genset yet.? It was suggested to me by one of the engineers at Thunderstruck that I could do it with the ME1616 with a rectifier and regulator.? But I have not researched it any further.?

I have a 3cyl 12kW Kubota diesel that was a removal from a new excavator converted to all electric.? It is not a marinized engine and I will need to sort that out but it doesn't seem too difficult.? Mostly to do with the heat exchanger and associated pumps and plumbing.? I may also need a belt drive to better match RPM's to get the desired output.? Direct drive would be preferred and the ME1616 is rated at 38.46 rpm/v so that's is in the ball park (57.2V @ 2200rpm).? Have to consider voltage drop through rectifier stages to get proper charging voltage input to regulator?? More research needed...

BUT, after running my electric drive for two seasons I don't know that I need such a large genset (10kW).? I could probably do with 5 or 6kW rather that 10.? See my reasoning here:


Perhaps as a general rule of thumb the genset capacity needed for reasonable continuous cruise at 75 to 85% of hull speed (for a monohull) you can do with 65 to 75% of the motor kW capacity needed to get to hull speed.? So if you need 10kW to get to hull speed that would be 5.5 to 6.5 kW gen set for reasonable continuous cruise.? By continuous cruise I mean maintaining desired speed without drawing down batteries.? For me that's 5.5 to 6 knots cruise.? From my observations I can do that at about 5kW.? But I always want to consider having sufficient headroom that I am not running any of the components at 100% to get the desired performance.?? That gets me to 6 or 7kW genset?? But 5kW would get me at a comfortable continuous cruise at 5 to 5.5 knots with headroom.?



My boat is a 12,500lb monohull with a 28.3ft waterline.?
My boat is a 5,700 kg monohull with a 8.6m waterline.

More details on my electric drive conversion here:



Dan Pfeiffer

On 2023-06-01 10:01 am, Robert McArthur wrote:

Dan (and anyone else who wants to explain!),

Delving back a little...

On Fri, 24 Mar 2023, 3:03 am Dan Pfeiffer, <dan@...> wrote:

I got a 2nd 12kW motor to use as a generator with a 3cyl Kubota diesel I have (18hp) but have not built the genset yet.? The diesel is very compact and I figured I could get a 10-12kW 48VDC generator from the combo.? After 2 seasons of use I think a smaller genset would do fine.? Maybe 5-6kW.? I could motor at decent cruising speed with that.?? Your use may be different.?? Genset info:

?

I just got a quote from one of the few marine DC genset places, and unfortunately it matches what I could find from the others - a new 16kW continuous 48V DC genset is about AU$28,000 or US$18,500. Not installed. Ouch!!

?

I see above Dan you thought about getting around it with a self-marinised bobtail, connected to a ME1616.

I'm thinking of similar, but perhaps an already marinised Beta 20 connected to the ME1616 (another of which will be propulsion) since I am not particularly mechanically minded to self marinise.

?

Could you explain to a layman why, if using the ME1616, you would need rectifier or regulator? I thought the ME1616 already put out 48V DC (I presumed an actual 54V or so) with controller. Or would you replace the usual Thunderstruck kit controller with the rectifier and reg for the genset?

?

Since a brand new marinised kubota (Beta 20) could be less than US$8000, and the ME1616 is about US$1500, it looks about half the cost of buying a named brand 48V DC marine genset! Thoughts?

?

Another option for marinised is a Yanmar 3YM20. Neither though are a perfect rpm match for the ME1616 which is only (!) 12kW. But if I can spend US$10,000 for 12kW vs $18,500 for 16Kw then it seems a big win.

?

Rob

Dan (and anyone else who wants to explain!),

Delving back a little...

On Fri, 24 Mar 2023, 3:03 am Dan Pfeiffer, <dan@...> wrote:

I got a 2nd 12kW motor to use as a generator with a 3cyl Kubota diesel I have (18hp) but have not built the genset yet.? The diesel is very compact and I figured I could get a 10-12kW 48VDC generator from the combo.? After 2 seasons of use I think a smaller genset would do fine.? Maybe 5-6kW.? I could motor at decent cruising speed with that.?? Your use may be different.?? Genset info:

?

I just got a quote from one of the few marine DC genset places, and unfortunately it matches what I could find from the others - a new 16kW continuous 48V DC genset is about AU$28,000 or US$18,500. Not installed. Ouch!!

?

I see above Dan you thought about getting around it with a self-marinised bobtail, connected to a ME1616.

I'm thinking of similar, but perhaps an already marinised Beta 20 connected to the ME1616 (another of which will be propulsion) since I am not particularly mechanically minded to self marinise.

?

Could you explain to a layman why, if using the ME1616, you would need rectifier or regulator? I thought the ME1616 already put out 48V DC (I presumed an actual 54V or so) with controller. Or would you replace the usual Thunderstruck kit controller with the rectifier and reg for the genset?

?

Since a brand new marinised kubota (Beta 20) could be less than US$8000, and the ME1616 is about US$1500, it looks about half the cost of buying a named brand 48V DC marine genset! Thoughts?

?

Another option for marinised is a Yanmar 3YM20. Neither though are a perfect rpm match for the ME1616 which is only (!) 12kW. But if I can spend US$10,000 for 12kW vs $18,500 for 16Kw then it seems a big win.

?

Rob

?

Reuben is getting closer to what might be required.

Raj, is your regular trip 30 miles round trip or one way? ?

In either case, your current boat converted to Torqeedo power as suggested will have a usable range around 18 miles at 25mph with 1 Torqeedo Deep Blue 40 battery, according to the Torqeedo specs. ?That battery has a list price of $32k US. ?Given that range, you’ll need 2 of the batteries to make a 30 mile trip in 75 minutes of run time. ?The batteries are just over 600# each. ?So you could repower your current boat with Torqeedo motor and batteries for $90k US. ?Then you’ll need charger(s). ?You should also consider the time to recharge the 60+kWh used going the 30 miles once attached to a suitable shore power source. ?Lastly, due to the high tech nature of Torqeedo products, they are not available with factory support in some countries. ?I don’t know if Guyana is on their list.

If your monthly gasoline bill is around $1000 US, it will be a long time before you break even on the investment. ?

With your current outboard, parts and service should be readily available, performance is better, and re-fueling takes minutes, not hours or days. ?It’s all about the trade-offs, and while I am a huge proponent of electric conversions, you would be making considerable sacrifices to go electric for how you use your boat. ?Yours is a big project and pretty expensive to do just to see if it works. ?What happens if after $100k US, it doesn’t meet your needs? ?Just something to consider.

Eric

?

One more question - with the load you carry (persons and gear) - how much HP do you now require to go the speed you want and size and type of current boat.?

a deep V hull is not needed for river cruising and takes more power to go the same speed as a modified V hull.?

On May 3, 2023, at 9:08 PM, Dave Yamakuchi via groups.io <dyamakuchi@...> wrote:

?

Matt is of course 100% correct on the fineness of the welding cable strands being more susceptible to corrosion.? Finer strands _do_ lower the inductance though, which might be an advantage depending on your controller but...

In any case I go with Diesel Locomotive Cable for anything exposed to elements.? It's tinned, has finer strands than the standard stuff, and is about as rugged as you'll find without going to something exotic.? You should at least tin the _connections_ if you aren't using tinned cable.? I know you said properly crimped, but tinning afterwards goes a long way to combat the corrosion.? It always starts on the ends.? Shrink wrap too afterwards regardless.

I'm sceptical about the other fellows recommendation regarding the bypass for cell balance though.? You mentioned having eight wires for each bank, which I assumed was two for each 12V cell for charging and two for sense.? 16 total.? Double check in the charger's docs but it would be unusual if the charging was through one pair but the balance was through the sense wires.? The charging will be through the bigger wires.

Best of luck!? :-)

On Wednesday, May 3, 2023 at 07:12:15 PM CDT, Matt Foley <matt@...> wrote:

Just an FYI. Welding cable is not advised on a boat.? Its not tinned and has very fine strands which will corrode quicker. Some of it is not resistant to diesel fuel. Diesel can literally melt the insulation away. I assume you will not have any diesel on your boat, but still.?

Matt Foley?

Sunlight Conversions

Perpetual Energy, LLC

201-914-0466

On Wednesday, May 3, 2023 at 01:19:42 PM EDT, Myles Twete <matwete@...> wrote:

First of all, you can certainly split up a pack into multiple boxes---this has been done since the first EVs were produced back in the late 1800’s.? I have no comment about aluminum except to be sure that’s what you really want (vs, say, wood/glass/epoxy molded to the hull).? With my 700ah, nom. 42v pack on , I have my pack split into 4 subpacks, each of the same nom. 42v (31v to 49v Lithium Ion).? Same story with Dan Pence’s “Ginger” (one of the first noted E-boat conversions in recent decades and 3^rd earliest or so at evalbum.com --- Dan uses the same battery modules as I use and has a row of batteries on the starboard and one on the port side. ?He has his mounted in a ply/glass/epoxy cavity originally built and sized for lead-acid batteries back in the late 1990’s---the cavities fit these ex-THINK EV Enerdel stacks well. ?He and I both use 4ga wire from each 35ah stack thru fuses to common points on each side.? Then larger gauge cable to connect the starboard and port packs.

?

Details matter. ?You indicate your pack will be 280ah at 48v and that the cells themselves are 280ah. ?Given that, your splitting of the pack results in two 280ah 24v packs in series.? Size your cables based on how much current you ever expect to draw from the pack.? Let’s say max. 7.5kw, then we’re talking about 150amps max. ?So sure, a gauge of 1, 1/0 or 0 probably would be fine.? Make sure you have a fuse near each of your 2 half-packs.

?

As for BMS connections, it’s not really as simple as presented by Dave.? Yes, the cell connection wires are “sense” wires but they typically are also “bypass” wires---that is, they need to pass the current that your BMS card attempts to bypass cells with.? And even 100ma of bypass current thru a tiny, long wire can cause millivolts of voltage drop which ruins the ability of the BMS to properly sense the voltage.? On an electric lift truck application I worked on, we found that 22 ga wires were inadvertently used instead of what we spec’d which was 20ga.? This difference caused cell balancing to be pretty ineffective.? Separate these functions (bypass and sense) and this problem goes away, however most of the BMS boards used until recently do not separate these.? Maybe yours does?

?

Here details really matter. Cell balancing for our under 10kw boating applications should not require more than 1-2 amps of cell bypass current.? On my boat, I have 20 remote BMS cards.? Each has the capability of bypassing up to 12 series cell pairs at about 100ma of current from a 35ah pair of cells.? This results in about a 10mv/hour balance rate, which is plenty if your cells are not all out of whack and not daily charging and discharging the pack deeply for weeks at a time.? Here use-case is important.

?

Your 250a Daly BMS makes me scratch my head---and the website for Daly doesn’t help me understand it any better.? Do you have better information on these?? Why on earth do they need to handle 250amps?

?

Thanks.

?

-MT (26’ The Reach Of Tide --- converted to electric in 2003)

?

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of aasmith970@...
Sent: Wednesday, May 3, 2023 2:54 AM
To: electricboats@groups.io
Subject: [electricboats] Splitting 48V System Into Two Boxes?

?

I have a question about the feasibility of splitting up my 280 amp hour 48 V system into two aluminum battery boxes, that I will be custom making making. I am constrained on the space in my Newport 28 sailboat and it would be much easier and balance the way much better if I split the bank..?

I am concerned, or the question is will the leads being longer from one system to the next, and the BMS leads being different links affect the current/reading of the BMS?? The leads going between the two boxes would be made out of double00 welding cable with properly crimped terminals while the leads going between the individual cells in the boxes will be copper busbars.?

Should all the BMS leads be the exact same length or can eight of them be 2 to 3 times as long as the other eight the boxes will be about 30 inches apart?

280ah new cells from Docan
250 amp BMS Daly
Delta Q charger + 150 watts solar
7.5 KW system from Foshan Green Motor?

thanks for any and all comments.?

Aaron?

On May 16, 2023, at 21:12, rragbeer@... wrote:

?Hi Reuben

I have not yet finalized on a boat size. ?The more information I collect, especially from the responses I have had so far, I am more I am inclined to consider a vessel which I can use for living quarters if I would like to overnight on the river instead of back in the villa.

The outboard vessels which are around today in the river can do the 30 miles in about 55 min. ?I do not mind going slower but more than 2 hours to do the trip may not the suitable. ?Your two 10kW motors cruising for 5 hours at 5 knots would do the trip in just over 5 hours. ?Am I calculating this correctly?

Budget - I truly do not know. In my thinking, 50 to 70 k was the figure but this may not be realistic and I have this number simply based on pure guesswork.

I do have the full solar set up for the villa and will likely be expanding the system so I will have access to solar power for charging.

I am inclined to go electric ?because we are likely at a point where the advances in electric will be so much in the next year or 2 that my investment in a gas outboard motor may be not the best bang for the buck. ?I am still 50/50 on this due to speed and possibly cost.

Appreciate the response.

Raj

-----Original Message-----
From: electricboats@groups.io <electricboats@groups.io> On Behalf Of Reuben Trane via groups.io
Sent: Tuesday, May 16, 2023 6:52 PM
To: electricboats@groups.io
Subject: Re: [electricboats] Newbie - 20+ foot boat for wide/long river in Guyana, South America

I’m an advocate for electric propulsion. Before being able to offer any suggestions, one needs a bit more info.

1. How big a boat are you considering?
2. What speed do you want to go and for how long?
3. Budget?
4. Excess solar power for charging?

Most likely the battery will be the most expensive component. You can build your own using cells from Winston or other manufacturer - no more difficult than doing model trains as a youth.

The major outboard manufacturers are just beginning to offer electric outboards. Torqeedo has a variety of products - both outboard and inboard.

It’s easier to go slow - but speed can be done with modest distances/operating time.

As an example, my 12m cruising cat has a 1,000AH/48v LFP battery using Winston cells and weighs close to 1,500#. My two 10kW motors can cruise for 5 hours at 5 knots.

Best wishes,

Reuben Trane
Mobile: 786.303.1013

Hello
I have recently joined the forum and have been following the topics with great interest.? Within the next few months, I would like to purchase a boat (new or used) for use in a fairly large river with the average trip being 30 miles and other shorter trips.? I have looked at the boats in use now, and generally they are all 20 to 30 foot length with outboard engines - 75 hp to 200 hp.? It takes about 50 min to travel the 30 miles depending on how rough the waters are, and while there is not much traffic, there are some vessels which have 2 200HP engines and makes quite a big wake.? The gas is about $120 USD.? I expect to use the boat twice per week for the 30 mile trip and twice a week for shorter trips and this is likely the maximum use; it may be less, not more.
Gas is likely to continue to increase in price.? I will be operating in a completely off-grid environment with full solar capability for the villa - PV panels, charge controller, battery bank, inverter, backup generator.? We get sun pretty much all day.? Everything including groceries and gas is a 10 min boat ride away.? No roads.
I am considering electric engines and have begun to ramping up my knowledge. Since I am starting completely from new, I figured this may be an advantage but perhaps not.? A few very broad questions and any guidance, input, feedback, cautions would be most welcome:
1. Should I go electric?
2. Is there a specific boat design for use with electric engines and river travel.
3. Budget - No idea. What can I get for 30k, 50k, 70k?
Thanks kindly for any input
Raj

?

From what you describe, electric is economically viable, but marginal depending on what you value. My reasoning is that your fuel bill is ~$1000/mo and that would support roughly $70k of investment @12%.

How much do you have to carry, and do you have to go over 32 mph for an hour?? 75 hp for an hour would take about a 60kwh battery.??
That is heavy and costly enough to be questionable.
If you consider
-a lower speed
-a lighter more efficient boat -long stabilized mono (tri) operating at a lower multiple of hull speed or a foil assisted cat (lighter, higher speed)
you could dramatically reduce your power needs and cost.?

The kicker is that those big batteries could be very useful to your off-grid villa when not powering the boat.

If this boat must be big, heavy, fast, and conventional deep V, electric may be cost prohibitive.

?

William Atkin designed a couple of paddlewheel riverboats. Lady of the Lake is one that comes to mind. Designed for a 10 hp diesel IIRC. I think it’s perfectly suitable for an electric motor.?