Electric propulsion

[Larry May]

I was very impressed by the electric propulsion system for Czarina in WB 198. I immediately scrapped my plans to hang an outboard on the back of the 22.5' x 7' trailer sailer I will start building this summer in favour of an electric system.

I've looked into packaged systems from Beckman and Elco - talk about sticker shock! I know about Glen-L's design to power an old outboard lower end - seems like it would be a bit of a drag.

The equivalent of 3-4 hp powered by 36V DC should be all I need. Something like the bottom end of a Torqueedo with a folding prop would be great. It could be faired into the aft end of the deadwood. There would be no moving parts (shaft) penetrating the hull, just wiring!

Anybody know where I could find such a thing?

[mcdenny]

http://www.re-e-power.com/

Makes exactly what you want in three different sizes. Also expensive, though.

A lot depends on how much speed and range you need. On the low end you could adapt a common bass boat trolling motor. Re-e-power would represent the high end.

You can see a brief description of my electric boat (about the same size as Czarina) at wolfeEboats.com. The web site is just a place holder until I get the real one up - hopefully another few weeks.

I'd be glad to help size a system if you supply boat weight and waterline length, also speed and range requirements. PM or public - your choice.

Batteries make good ballast.

[Tom Mac]

Hello McDenny, What electric motor goes with a Joel White 12 1/2 boat. I use the motor to get out of the canals, a 15 to 20 min ride both ways. Thanks Tom Mac

[GregH]

FWIW, I couldn't agree more with McDenny's suggestion of Re-E-Power. I first learned of them several years ago while attending Strickly Sail in Chicago. I'm building an 18' version of Tom Garden's TomCat, and fully intend to intall one of their units. I spoke with Kevin of Re-E-Power just yesterday while at the 2008 Strickly Sail at Navy Pier in Chicago. They're working with the builder (Hutchinson?) of Horizon Cat to offer their power system as an option. They have one at the show, and it's a very clean install, mounted just behind the keel/centerboard trunk.

As to price, however, I do disagree-- A typical Re-e-power installation for a Horizon Cat or something similar is $4k to $6K, including batteries. Compare this with the cost of a new 8 hp diesel. Kevin recommends using 6 volt golf cart type batteries for now. However, with the push that the auto industry is making in the development of better batteries, the next few years should be very promising for electric-powered boats also.

[Larry May]

Wow! That was fast. Thanks so much. The E-power looks exactly like what I had in mind.

[StevenBauer]

Re-e-power has some cool videos on youtube:

www.youtube.com/watch?v=d-Wsefz8FOk

[mcdenny]

Greg, The cost comparison with a Yamaha 4 stroke 8 hp electric start outboard is not so favorable - the O/B is $1650. (admittedly before you factor in the ugliness hanging on the transom)

Tom, I'd think a Haven 12.5 would move easily with a trolling motor; either clamped on to the transom or built into the rudder. Something like this:

http://www.minnkotamotors.com/products/motors/detail.asp?pg=fem about $800 plus batteries

the 24v 80 lbs. thrust model would be about 1-1/4 hp; which should drive your boat (12.5' wl; 1400 Lbs weight) at about 4 mph. Two gp 31 12v batteries would weigh about 65 Lbs each and give top speed for 1.5 hrs; half power would be 3.3 mph for 3.3 hours (11 miles range). The batteries might fit under the sole but for sure you could put one under the foredeck and one under the after deck.

Four 6v 220ah (66 lbs) golf cart batteries would more than double the range; harder to stow, though.

[GregH]

Yeah, an OB would certainly be the least expensive way to go. But in addition to the noise and fuel smells, there's one major (IMHO) problem - UUUGLY!!!! (Sorry, Joe)

[Tylerdurden]

http://www.minnkotamotors.com/products/motors/detail.asp?pg=sem

I have sent several e-mails and a couple of phone calls to RE-E-Power with no response. If somebody has spoken with them I would love to hear.

Take a look at this setup, easily modified for use and better priced.

[MiddleAgesMan]

Czarina's electric propulsion system came from NGC Marine.

http://www.ngcmarine.com/index2.html

They offer systems from 8 to 26HP, priced from $6700 to $8700.

At 8HP that's a pretty expensive system but the 26HP model is priced competitively IMO. IIRC that's the one the owner selected for Czarina.

[GregH]

To Tylerdurden- Most of the RE-E-Power folks are at Strickly Sail in Chicago this week.

[willmarsh3]

Given the expense of these systems, it may be worth considering building a motor well and putting in a trolling motor. I have a 80 lb thrust one and two batteries on my Elver. Total costs around $800 including battery chargers. With trolling motors just beware of ones that accomplish speed control with speed coils. You want the PWM type speed control. I looked at doing a motor well but have not come to a way to do it that I am comfortable with.

[Tylerdurden]

To Tylerdurden- Most of the RE-E-Power folks are at Strickly Sail in Chicago this week.

I had been calling and e-mailing a month or two ago.

I gave up and will continue to do so. Just a note or a message saying busy now try back would have done but you snooze you loose.
Its always a good way to garner support by ignoring your prospects.

[Gary E]

Prospects???... tire kickers is what your talking about...
we didnt even call them suspects for new CNC machine tools...
Lookie lews... never buy a new machine but take up a lot of time...
You on the other hand, may have a full pocket of cash ready to spend... right??

[Tylerdurden]

Prospects???... tire kickers is what your talking about...
we didnt even call them suspects for new CNC machine tools...
Lookie lews... never buy a new machine but take up a lot of time...
You on the other hand, may have a full pocket of cash ready to spend... right??

I am in process of powering. I skipped these guys for the reasons above. Went with an e-tek. Is that ok with you?

[Gary E]

Sure... use a mouse in a wheel for alll I care

[Tylerdurden]

Sure... use a mouse in a wheel for alll I care

Then why don't you take it to the bilge. Do you see me up here ranking on people?
You and Dan act like its your exclusive right to hammer on electric buffs but not once have you contributed anything positive.
I still would like to see your qualifications. You two wanted mine.
I get a feeling out of the three of us I am the only one to work in the industry.

[Bob Cleek]

After a fair amount of research, I've pretty much concluded that battery powered electric propulsion is pretty much in the same class as the perpetual motion machine. Yes, small trolling motors and the like work fine for light, easily driven hulls moving through calm water. They lack the punch to move a boat in any sort of weather or wave conditions. I spoke with the builder of a conversion written up in WB some time back. The article was most encouraging. He told me it was an exaggeration. The electric system, installed at great cost was, as he said, okay for moving the boat in and out of her slip in the marina, but not enough in terms of power or battery life to move her anywhere else. You'd probably do a lot better with a lunchbox gas generator and a 120 electric motor than to go with batteries.

[Gary E]

"electric buffs "???
Mark,
This disagrement started out when someone asked about REPLACING a 45 or 50 HP Diesel... and you and others deemed a electric system of much less power would do ( it WONT) and at substantially more cost. Does that make sense?.. NO, it never will.

So, what ever your qualifications are, a 5 or 25 HP electric will NOT replace the current Diesel's installed HP... My qualifications?.. ME with what was at the time the largest Machine Tool Builder in the WORLD. They build metal cutting machine tools and Computer Numerical Controls to drive them.. Some of the small spindle drives were 10 or 15 HP, and some of the larger were 100 HP. Many 40 and 50 HP drives in the middle. Slide drives where control of position, acceleration, deceleration, torque, and speed were all part of the requirements.

I see the above HP mentioned as 1 1/4 ?? Ok, what ya gona do with that?..PLAY?? fine, have at it.

Now what are your qualifications?

[GregH]

HEY! You two "experts" get lost!

Larry started this thread to get some infomation- I'm sure that he, and others, are as appalled as I am that it has gotten completely off topic and degenerated into a moronic squabble. Shame on both of you.

[David Hughes]

Gary E.
Your useless dribble isn’t even good enough for the bilge. Maybe if we continue to taunt you about alternative electric propulsion systems, you will finally go away. Please go away and let the people who want to learn for themselves about the advantages, disadvantages of electric drives, and stop polluting the forum with your useless blather. Maybe you can try your dribble on the likes of Ford, GM and Chrysler and tell them to forget about those pesky hybrids.

The fact is there are many electric drive systems out there that do work quite well, both manufactured and home grown. Like with anything, each application needs to be carefully considered and designed to meet the needs of the application. This thread was started concerning a 22-foot trailer sailor, likely a very good application, the 40-foot schooner, maybe not. I really don’t know, but I do suspect one could be designed for that boat. Will an electric drive cost more then an OB hanging of the back? Probably, so will the wooden boat he will be hanging on versus a fiberglass boat he could buy off of Craig’s List.

Another fact, motors, gas or diesel, don’t do well in most day sailors for if one actually sails (probably not the likes of you by the sounds of it) one would be lucky to use a full tank of fuel in one season. Why don’t you ask your mechanic what infrequent use, while being under loaded does to an engine after several years?

Alternative electric systems are a viable alternative. Will they replace diesels, likely not, but I do suspect they have a place in the future.

[Bob Adams]

If I was building from scratch, I'd consider a convetional drive(maybe with a prop pocket), with a used golf cart or forklift motor (2 to 7.5 hp) with a packaged pulsed DC controller. I'd bet you can scource everything needed for under $1000.00. I just sold this on EBay for under $60.00

http://i11.ebayimg.com/02/i/000/d5/84/2f24_1.JPG
This will handle 275+ amps and is energy efficient. On your 22 footer you could maybe do somethin like a retractable propeller ala Dispro! That would be neat. My 2 cents.

[David Hughes]

I didn't mean to shut down the discussion on electric drive alternatives just wanted to get it back on topic.

Personally, I feel electric drives are well suited for day sailors that hang out at a dock where you can plug in to recharge. My opinion is based on personal experience. I built a 48-volt inboard system to replace a defunct Gray Marine Sea Scout in my Rozinante. With eight 6-volt golf cart batteries, this system could push the Rozinate around for @ 8 hours at 3 knots or 2 hours at full throttle. Since I mostly sailed, I thought this amount of time would fit my needs and it essentially did.

The problem with my system was related to battery recharge. Since I hung out on a mooring, I had to rely on wind and or solar. I tried wind, and a turbine with a 4-foot diameter blade is just too much to manage on such a small boat. To make solar work, I would need more panels then I had deck. So that forces you to come into a dock periodically to recharge over a 8-12 hour period, not really something I wanted to be forced into.

With regards to the performance of the electric drive, it was great, instant on when needed, no need to have the engine idling. What I found was that I used it mostly to ghost into tight areas and if need be I could use the electric drive for that extra push to retain steerage. I never found it to be under powered in any conditions.

Bob from EV America in Wolfeboro NH (http://www.ev-america.com (http://www.ev-america.com/)) supplied all the electrical components and the technical support I needed to wire it up, which to my surprise was relatively easy. The hardest part for me was mounting the electric motor to facilitate tightening of the drive belt, but Elco (http://www.elcoelectriclaunch.com (http://www.elcoelectriclaunch.com/)) seems to have that figured out.

Good luck in your search for knowledge. The best thing you can do is first determine your needs, identify a system that will meet those needs, develop costs, "talk" with others who have done it, then decide if any of the inherent shortcomings are acceptable to you. Electric drives certainly do have some benefits, but they most certainly have some disadvantages that you needed to completely understand as you move forward.

By the way, I tried contacting Re-E-Power through their web site and also got no response.

[John Hutchison]

Considering an E-pod can be purchased from RE E Power, does anyone know the performance differences between an inboard unit and the pod. I'm looking at powering my 1932 Fishers Island 23 and want to make the least modifications to the boat as possible. The pod seems to make sense for my needs (daysailing, in/out of the slip) but I'm sure about build quality, reliabilty, performance, etc. Anyone have experience? How about folding props on a pod?

[Dan McCosh]

I think it's worth noting that the best of today's lead-acid batteries have a capacity of about 2 amp/hours per pound. This is the primary limiting factor in an all-electric drive. The batteries quickly become the most expensive, shortest-lifespan, and duration-limiting factor in the system. The issues become very significant as the displacement of the hull increases, and the needed range increases. If the requirements are low, then the cost and performance becomes manageable.

[Bob Cleek]

Not to mention the WEIGHT of the batteries!

[paladin]

I have mentioned on another forum, and a bit on the WB forum....the cheapest and easiest battery system is golf cart batteries or similar, which is also the heaviest...to construct a battery yourself in the manner of the $7000 systems used by the fancy electric car guys, you can buy one that is much lighter in weight, or you can build it yourself from individual cells for half the price....the manufacturers suggested lifespan is 700 recharge cycles based on fast charging at 1/2 rate....or a 2 hour recharge....this generates heat and does the battery no good. Reduce your charging to 1/4 rate or less and you will more than double the number of recharge cycles, now figure out how many times a year that you will use and fully recharge the system to get the estimated full charge. If you do not completely discharge the battery, and use a slow recharge cycle, and a 4 step charger, then the expected life of the batteries is approximately 10 years.....longer if you do not rapidly charge/discharge them every day....now calculate the price.

[David Hughes]

In my case, 8 trojan T105 (Golf Cart Batteries) with a 20 hour amp hour rating of 225, weighed 62 pounds each. So the total weight of the batteries was just shy of 500 lbs, or 7% of my displacement.

Now compared to an engine, Yanmar 9 HP @ 160 lbs, transmission @ 50 lbs, 20 gallons of fuel at 150 lbs, fuel tank at 20 lbs for a total weight of 380 lbs.

Really not that much differance in total weight. Granted you could go for about 40 hours on the 20 gallons of fuel.

[willmarsh3]

I have a 100ah 24v setup (2 Werker group 31 lead acid) which cost $160.
If I use Panasonic NIMH D cells it would cost about $6022. It takes 10 cells in series to push 24v. Each cell (Digi-Key Part Number P019-ND) puts out 6.5 ah. Thus I would need 16 of these series or 320 D cells. The cost would be about $6022.

The weight of the lead acid batteries is about 150 lbs. The total weight of the NIMH cells is (6oz a piece) 120 lbs.
If I could find large format NIMH (Cobasys seems to have a lock on the patents and won't sell large format NIMH directly to consumers) it might be cheaper and lighter.

If I use lithium ion then I could get a pair of Valence Technology U charge. This is a 12v battery with 100ah of capacity. I use 2 of these to make 24v (actually slightly higher voltage). Last time I checked these were around $2000 a piece. They would be 49kg or 110 lbs.

I think the Peukert effect would be less for NIMH and LiIon than lead acid.

The charging would be more complex for the NIMH because there are so many cells in parallel and series. How would the charging be balanced?

The lead acid batteries will last about 5 years if taken care of and kept charged. Chuck says the NIMH will last 10 years. I don't know how long the lithium ion will last but my laptop batteries have lasted about 4 years. Also the laptop battery seems to undergo quite a high self discharge.
Over a 10 year period:

lead acid $320
NIMH $6022
LiIon $8000 (I'm guessing these will last 5 years)

I would go with Lead acid hands down unless there was a serious need to trim every bit of excess weight. I'm watching for prices of Lithium ion to come down a lot. It might be 5 or 10 years though.

[paladin]

The prices at digi-key are commercial retail prices...when you start buying cells in large quantities you set up a commercial account and the price drops about 60%

[dirtsailor]

During one of our messabouts I had the pleasure to go for a ride on this boat:

http://farm3.static.flickr.com/2372/2212869607_3e19cc7d56.jpg

It's power arrangement can be seen here:

http://www.evalbum.com/492.html

It was so nice no noise at all, none, almost eerie, I kept thinking something was missing. Anyways the owner has compiled a good bit of information and posted it in various places on the net about the performance and components used. The link above is a good start.

[johngsandusky]

I agree that weights for both systems are similar, electric almost always weighing more. But the batteries can go in the bilge, adding stability. The diesel engine and tanks are usually right around water level, and don't help at all. They also take more usable space.

[willmarsh3]

FWIW I found these folks.

http://www.ossapowerlite.com/

Apparently they have taken the diesel hybrid approach to its logical conclusion.

[sngatlanta]

Hey guys I'm new here but just happened to have looked in. About 2 years ago I was looking into this and saved this link.

http://www.thunderstruck-ev.com/sailboatkit.htm

They refer you to these guys for mounts

http://www.electric-sailboat.com/

and it looks like they are getting ready to release a full set up.

[Dan McCosh]

I agree that weights for both systems are similar, electric almost always weighing more. But the batteries can go in the bilge, adding stability. The diesel engine and tanks are usually right around water level, and don't help at all. They also take more usable space.


I'm not sure how the weights can be similar. The energy in a gallon of diesel fuel is equivalent to the energy in about 400 lbs. of batteries, as a rough estimate. The diesel fuel weighs less than 10 lbs.

[Tylerdurden]

I'm not sure how the weights can be similar. The energy in a gallon of diesel fuel is equivalent to the energy in about 400 lbs. of batteries, as a rough estimate. The diesel fuel weighs less than 10 lbs.

Can't argue with that logic? LOLhttp://www.woodenboatvb.com/vbulletin/upload/images/icons/icon10.gif

[Tylerdurden]

I think it all boils down to this. I can refuel my electric sailboat for free with the wind genny or regenerating while under sail.
The diesel fans just count on always being able to hit a fuel dock but days are coming where the dock will be empty like during the 70's
I will still be able to motor. Fuel on not.

Besides sometimes its just better to whisper.

[mcdenny]

To amplify Dan's (correct) point:

A modern engine running at optimum speed burns a gallon of gas to produce 9 kilowatt-hours of mechanical energy; a diesel can make 13 kWh from a gallon. Electrical energy from the grid costs about ten cents per kWh – that’s only 25% of the cost of an equivalent amount of energy derived from burning gasoline in an engine. Diesel has a higher energy content per gallon but is still 2.5 times more expensive than electrical energy.

Electric 'fuel' is a lot cheaper than petro and can be gotten for free via a wind generator or solar panel but it is 50x heavier and 10x bulkier to store. The "tank" costs a fair bit more too.

[jimmy]

Quote:

Originally Posted by Dan McCosh View Post
I'm not sure how the weights can be similar. The energy in a gallon of diesel fuel is equivalent to the energy in about 400 lbs. of batteries, as a rough estimate. The diesel fuel weighs less than 10 lbs.



Can't argue with that logic? LOLhttp://www.woodenboatvb.com/vbulletin/upload/images/icons/icon10.gif

You're not just comparing the weight of the fuel, you're comparing the weight of the whole system. Sure batteries are heavier than diesel, but a diesel engine weighs a lot more than an electric motor (my diesel weighs ~500 lbs) and the diesel usually has 1 or 2 batteries anyway. Depending on the number of batteries you decide to install, an electric system could be lighter than a diesel system. For a lot of boats, electric power doesn't make sense, but sailboats that usually only use power to get away from and back to the dock are one of the few applications where it might be perfect.

[DaveWhitla]

I've been researching electric power for exactly that usage in my own boat. A German motor builder whose name escapes me at the moment is currently building some very high efficiency brushless electric motors for marine applications. For storage I'm planning on trying the gell-cells I recovered from my 30kVA UPS. In their use in a UPS they are constantly charging and discharging without serious degradation. And they can deliver huge current. As far as weight is concerned I think you have more freedom for better weight distribution with batteries than fuel - but the insulation precautions might be a further inconvenience.

Don't know if it has been mentioned that marine diesels only operate efficiently at their single design RPM. Well designed electric motors operate with little variation in efficiency across their entire range and can briefly exceed their nominal output by several times. In maneuvering I think they have a clear advantage with maximum torque being delivered immediately.

I'd like to see more detail from manufacturers regarding regenerative charging though. I would expect regenerative charging to be the most elegant solution for my intended usage if it is sufficiently well developed.

I wanted to build sans-engine originally but the way marinas have taken over here it's neither practical nor legal anymore. I'm very interested in any developments which people can link to.

[georgel]

I just read a post on this thread Indicating That E power would not be adequate for the intended usage. It made me chuckle. Some years ago I worked on the refurbishment of a mothballed Navy tug. It had 8 20+ ft. long Detroit diesels driving generators. Which in turn powered 2 Electric drive motors. The tug was a WWII Ship built to tow Aircraft Carriers. The largest tugboat I have ever seen. Would that be enough HP?. Grin. putting together a system out of surplus parts can be cheap. The speed controller Is the most expensive part. Starter motors, Forklift motors, Golf cart motors. Etc. Lead acid has no real competition for marine use. Unless you happen to have a stash of Nickle Iron batteries. the NI are good Indefinitely. But they have memory issues similar to Nicads. But this issue can be overcome.

[Thorne]

http://www.luckhardt.com/timlk-jet1.jpg

Rode in a Diablo with 4 golfcart batteries in the bilge and this on the stern -- quiet and reasonably powerful...

[Hwyl]

Would it plane?

[Concordia...41]

The September Practical Sailor issue has about 8 pages on multiple companies in the electric propulsion market, their successes and failures. Sounds like lots of research and lots of work going on (and lots left to do).

A couple of months ago we had a 27' come through here with the alleged latest and greatest Elco electric drive. It was cool and a wonderful concept.

It sounded like a sewing machine with the engine box up and other than your hand on the hull, you couldn't tell it was running when the engine box was down, but after multiple changes to batteries and engine, it still would not push that relatively little boat against the current long enough to make it back to the dock after an afternoon's sail. :(

[adam96]

We ended up choosing a Bellmann drive (http://www.bellmann.nl/drivesystems/english/?page=Home ) system for this 16ft classic tender. It's a simple, straight forward, and complete system that we have been very pleased with. One of the nicest features is the digital read out with % battery discharge, %power usage, and estimated time remaining at current speed - all programmable to set voltages, etc. Definitely worth a look. Adam

http://i144.photobucket.com/albums/r178/alangerm/P1012482.jpg

[Sailor]

That's one beautiful little craft.

[Tylerdurden]

The September Practical Sailor issue has about 8 pages on multiple companies in the electric propulsion market, their successes and failures. Sounds like lots of research and lots of work going on (and lots left to do).

A couple of months ago we had a 27' come through here with the alleged latest and greatest Elco electric drive. It was cool and a wonderful concept.

It sounded like a sewing machine with the engine box up and other than your hand on the hull, you couldn't tell it was running when the engine box was down, but after multiple changes to batteries and engine, it still would not push that relatively little boat against the current long enough to make it back to the dock after an afternoon's sail. :(

Sounds like a 75 watt solar panel would help with that. Also if he is using more than 50% capacity to do do the job the pack is sized wrong. Biggest mistake is to cut corners on capacity.

[gert]

What amount of electric HP or KW is equal to 12 diesel HP at the prop shaft?

Thank-you

[soba]

Through a motorcycle supplier I have dealings with, I have access to Lithium Iron Phosphate batteries at a price that is only twice that of AGM's. (counting by energy density)
While they do have some issues with deep cycle discharge, they are far safer than comparable LiIon batteries (cobalt oxide, I think?) for wooden boats, and as they take up far less space than AGM's or standard lead acid batteries, filling the same space I would with LiFePO4's would get me almost 4 times the energy density by volume. They are rated for 2000+ full duty cycles and full replacement of the bank would be less than paying for diesel maintenance (at our shop rate) each year for a similar time.
They are meant for electric motorcycles (not scooters! Full on motorcycles) and have an impressive guarantee.

Can't wait to see what happens with capacitor technology. And digital speed controllers. Then all bets will be on! Mind you, I still love the sound of a one lunger...!

[soba]

Which is worst for the environment when (if) a boat sinks? Lead acid? Diesel? Lithium and associated chemical?

Whaddya think?

[gert]

Which is worst for the environment when (if) a boat sinks? Lead acid? Diesel? Lithium and associated chemical

Sinking isn't in the project scope!

[mcdenny]

Gert,

HP is HP, whether it's gas, electric, steam, nuclear.

Electric motor sellers like to rate their motors as "equivalent" to 2 or 3 times more powerful gas engines because generally they can push a larger boat than a same hp gas engine. The electric motor feels more powerful due to having full torque from zero rpm. Also there's no problem running a motor at full power as long as the batteries last while most people would not run a gas engine wide open for hours.

The low horsepower electric motors offered for boats can swing a much bigger prop (again - all that torque) than small gas engines so they are better at generating thrust.

If you are thinking of e power you need to consider the speed and range you need and see if electric can meet those needs. Electric use is limited by its relatively short range much more than by low HP. Getting a powerful electric motor is not the problem, its hauling around enough batteries to get a decent range.

Don't get me wrong - I'm a big fan of electric boats and absolutely love cruising along in silence but there is only a narrow slice of boat applications where they make sense.