Electro Beke

[Bubba the Pirate]

I mentioned this page in a discussion about my Bubba the Pirate Blog. I thought others might be interested in this detailed description of an electric motor install.

http://www.sailinguma.com/electro-beke/#why-electric

[CapnK]

I have been - Thx & Grog, Todd.  8)

[Cyric30]

Ive been watching Uma and there electro beke for a bit, and while i like the whole concept, what i cant figure out is what kind of range something like this would have? and its not for a lack of trying its simply i am no good at electrical stuff can any of you guys with more electrical knowledge shed some light on that (yes Light Pun intended)

[Bubba the Pirate]

I like their philosophical approach. It would not work for everyone but they don't have a work schedule per we and so they don't think much range is necessary. That agrees with the way I plan to voyage.

The word sailboat is a hidden grammatical command: "sail boat." I hope to use non-wind motive power as little as possible.  The auxiliary power will be just that; an auxiliary way to move the boat for short distances when needed.

That said, off the top of my head, I think the Uma folks were estimating  60 nautical miles. Now I have to read it again.

[SeaHusky]

There is a complete product on the market called Greenstar (used to be called Ozdrive).
Looking at their products may give a ballpark figure of what you can expect.

http://greenstarmarine.se/en/offert/

If I enter my boat weight as 4 tons they recommend their equivalent of an 18hp diesel.
If I choose 8 x 100Ah AGM I get 8h of ecodrive and 45m of full thrust.
Note that the motor can work as a generator and charge your batteries while sailing.

[CapnK]

Regen is always mentioned, but I wonder just how much that works out to, compared t how much it would slow your boat. Then again, a diesel prop hanging out there is doing absolutely nothing for you, sooo...

Joe on their website they have a graphic which shows the relationship between speed and charge used. At ~2 kts their range is like 100 miles, 4kts is 65 miles. I do not know if that means using up *all* of the power in the bank or not to reach those figures.

If you don't mind the equatorial bob-n-bake of a circumnavigation, and can stand off while waiting for a favorable tide/current speed to enter a port, well then IMO even that fairly limited range sure beats the heck out of oars or a yuloh. Can't sip a beer when you are the engine. :D

Best is that their homespun approach only set them back about $1500, including batteries. I have been really put off by the multi-thousands of dollars of the 'turnkey' setups. I would take a hard look at having a small genset onboard as a possible 'hybrid' solution.

[Bob J (ex-misfits)]

The projections made by many marine EV suppliers are extremely overstated & are a leap. Most projections for range from companies like Greenstar or Electric Yacht that have been made for my boat are not realistic. The one company I've found that takes the Peurkart factor into account for range in battery banks is Thunderstuck EV. My Sabre 28 with a 10KW motor, 235 AH FLA 48 volt bank discharged to 50% DOD would last 2 hours at 3.2 knots without going into hybrid mode. At hull speed 6.6 knots, 17 minutes. If I went with a 120 AH bank, 66 minutes @ 3.2 knots, 6 minutes at hull speed. Running a Honda 2000 watt suitcase generator I could motor in hybrid mode all day @ 3.5 knots without depleting the battery bank.

Regen, it's overstated for most boats that have a small water line like mine, just under 23'. Most folks out there using Electric Propulsion see little if any regen unless you're surfing down waves.  The one good thing about EP, you can spin the prop in lite air so there's no drag on the wheel & consume 0 amps doing so. Just like having a folding prop.

I think EP has potential but it all lies in the battery bank. I've done a lot of research into EP because I'm not putting another diesel in my boat. Hate the smell & noise.

Truth is however at this moment in time I'm struggling with either an EP system or just saying the heck with ascetics & putting a 9.8 Tohatsu on the transom & calling it a day. These are after all sailboats :)




I've watched the Uma videos & IMO they did take the long way around the barn. There are many DIY components out there that once bolted together become plug & play. The Greenstar system, I looked at it when they were at the Portland ME boat show two years ago, 8K....

[Owly055]

     I'm deeply suspicious of claims by electric boat drive manufacturers.   The author commented that large expensive deep cycle batteries were not necessary, a rather foolish statement, as nothing else will stand up to repeated  relatively deep cycles.  The  more deeply a battery is cycled, the shorter it's life expectancy, and it's not a linear relationship at all.   Except in terms of weight, you cannot have too many batteries.   It is a mistake to use anything but TRUE deep cycle batteries, and Marine deep cycles are generally NOT true deep cycle batteries.   Golf cart batteries are what one should be looking at.  In the end they will last far longer and costs will be far less.

    The implication that electric horsepower is not the same as gas horsepower is nonsense.   Horsepower is horsepower is horsepower, and it is well defined.    What is different is torque curves.  Horsepower is rated at only one RPM.   The horsepower and torque above and below that RPM is what is variable.   One foot pound of torque at 5252 RPM is one horsepower, at twice that RPM, it takes half the torque to make one horsepower, and had half that RPM, it takes twice the torque.  Wherever the torque and RPM correspond the greatest horsepower is where they take the horsepower rating. 

     What is interesting initially (to me) is the potential to use solar energy to propel a boat when in situations like the ITCZ (doldrums).   The problem is that you would have to tow a barge full of solar panels ;-)   At a dollar a watt, the solar panels themselves are affordable enough at about $5000.00 for enough to drive this motor.  At 14.25 watts per square foot, 4.8 KW would require 337 square feet of solar panels...... that's a lot of footage!  Clearly not realistic.   

     That said, electric drive does make sense for some sailboats, such as those used primarily for long passages where the system will be used briefly in harbor, but not if you have to carry a generator too.   A small Yanmar is an extremely reliable engine, very economical, and long life.  On a boat where one would use electric power, I suspect the total cost over the life of the boat would probably favor the diesel.   At least it would for me as I work on diesels all the time, and so would not be paying someone $100+ an hour for any maintenance.

                                                                                           H.W.



     A resistance throttle as is apparently shown here is grossly inefficient, and results in energy lost as heat.   The ideal system would use a pulse width modulation system.   An alternative would be to have circuitry that would allow batteries to be hooked in various series / parallel combinations for different voltages, but that is pretty complex.   Two ranges, 24volt and 48 volt, would be fairly easy to set up, and would minimize the use of the resistance throttle.   You would run wide open at one of the two voltages, throttling back only briefly when maneuvering very close to the dock or whatever.

     Direct drive is better than geared drive due to power loss through gears, but prop efficiency is a consideration to be taken in to account.   

     For regen to work significantly, a different prop would be required.  Better to have two props, one for power and one for regen.   A system with two props on concentric shafts with a way to clutch the shafts together could allow the drive prop to spin up the folding regen prop to produce power...............But it all gets pretty complex.    Regen is unrealistic as far as I'm concerned.   

     

The projections made by many marine EV suppliers are extremely overstated & are a leap. Most projections for range from companies like Greenstar or Electric Yacht that have been made for my boat are not realistic. The one company I've found that takes the Peurkart factor into account for range in battery banks is Thunderstuck EV. My Sabre 28 with a 10KW motor, 235 AH FLA 48 volt bank discharged to 50% DOD would last 2 hours at 3.2 knots without going into hybrid mode. At hull speed 6.6 knots, 17 minutes. If I went with a 120 AH bank, 66 minutes @ 3.2 knots, 6 minutes at hull speed. Running a Honda 2000 watt suitcase generator I could motor in hybrid mode all day @ 3.5 knots without depleting the battery bank.

Regen, it's overstated for most boats that have a small water line like mine, just under 23'. Most folks out there using Electric Propulsion see little if any regen unless you're surfing down waves.  The one good thing about EP, you can spin the prop in lite air so there's no drag on the wheel & consume 0 amps doing so. Just like having a folding prop.

I think EP has potential but it all lies in the battery bank. I've done a lot of research into EP because I'm not putting another diesel in my boat. Hate the smell & noise.

Truth is however at this moment in time I'm struggling with either an EP system or just saying the heck with ascetics & putting a 9.8 Tohatsu on the transom & calling it a day. These are after all sailboats :)




I've watched the Uma videos & IMO they did take the long way around the barn. There are many DIY components out there that once bolted together become plug & play. The Greenstar system, I looked at it when they were at the Portland ME boat show two years ago, 8K....

[Cyric30]

Owly55 touches on a point for me to ask this question.
As he said a small Yanmar, is very economical, and how long will it last with proper maintenance? 5,10,15 year? more?
Compare to batteries, how many will you need over the course of your boating life? a good solar battery isn't cheap and if you don't have enough and/or you discharge them to deep to often, your looking at new batteries every couple of year if your lucky.
So how many batteries will you go through vs. the life of a diesel?....

Its kind of hard to compare, i know due to cost of diesel and repairs, but same can be said for solar and wind and generator for electric.

what everyone's thoughts?
Im not advocating one or the other im curious about the comparison i guess.

[Bubba the Pirate]

Compare the electric also to the smell and the mess of the diesel.

In the tropics, even after you shut the engine down, the heat of the engine block seeps into the boat long after. The tropical heat is also harder on batteries. But I think in the day-to-day living the electric has a lot of advantages.

You could eliminate one thru hull as you wouldn't need a water intake.

If you add up fuel, filters, oil, impellers etc., I think the lifetime cost math would get much closer.

Less to worry about dirty fuel from some out of the way source.



I'm going to have a Honda 2000 onboard anyway for my Sailrite machine, so I am not so worried about regen. 

[Bob J (ex-misfits)]

Look at how many times we've all seen or heard about folks having engine problems.
With electric there's virtually no maintenance when compared to a diesel engine.
A couple of electric boaters on the Yahoo Electric Boat forum have had the same battery bank for 8 years.
James @ Electroprop has two solar panels on his boat & claims he can motor all day @ 3 knots on sun power alone.

I think in the long run going electric is not any cheaper than a diesel repower if you're a DIY. The good thing about it is you start out with a basic system & you can add from there as finances allow. Solar, Honda generator, bigger/better battery bank, you get the idea. 

[Owly055]

Good point about heat..... though my experience with diesels, and I work on them for a living, is that properly maintained, they have an extremely long life expectancy and very low maintenance.   It is not uncommon to see diesels with 15000 hours or more.   I  consider it a mistake to use sea water for engine cooling in any manner that requires seawater to be moved into and out of the boat (pumped).......but obviously I'm swimming against the tide here.   The best method would be the stainless steel skeg with engine coolant passing through it, or some other method that moves engine coolant into indirect contact with sea water instead of trying to move sea water to the engine.

I will say with confidence that the author will find himself replacing batteries at least annually if he uses the motor very often.  Of course most boats sit in a slip or on the hard most of the time, and that kind of sailor can expect considerably more battery life.   

Auxillary power for sailboats is always going to be a problem and involve trade offs.   The outboard solves some of these problems, but metal immersed in sea water, and cooled with sea water is guaranteed to have a short life..... salt water sticker or not.   And outboards often stolen.

                                            H.W.

Compare the electric also to the smell and the mess of the diesel.

In the tropics, even after you shut the engine down, the heat of the engine block seeps into the boat long after. The tropical heat is also harder on batteries. But I think in the day-to-day living the electric has a lot of advantages.

You could eliminate one thru hull as you wouldn't need a water intake.

If you add up fuel, filters, oil, impellers etc., I think the lifetime cost math would get much closer.

Less to worry about dirty fuel from some out of the way source.



I'm going to have a Honda 2000 onboard anyway for my Sailrite machine, so I am not so worried about regen.

[Owly055]

I would say some folks are blowing smoke up your ____  ...............   I'm not sure what kind of boat James is motoring, but let's look at solar panels.    The largest single panels are between 250 and 300 watt.   Let's take 275 watt x 2.   That's 550 watt.   750 watts equals one horsepower (approx).   What are you going to push through the water and how fast with .73 horsepower??  Those two solar panels are going to weigh in at about 80 pounds and cover an area of about 5.5 feet by 7 feet.   I would say that James is a BS merchant.  The 8 year battery bank is an equally outrageous claim.  It's a classic example of why folks need to take the "wisdom of the internet" with LOTS of salt.   You may motor your sailboat all day long on solar power only, but at 3/4 horsepower how far are you going to go?   I'd love to know where people came up with batteries for an EV battery bank that performed for 8 years!   I suggest you go to the local golf course and talk to the maintenance staff about battery bank life.  Real world people with real world experience.  We all have experience with batteries......... lead acid, nicad, lithium, etc, and none of that experience would even remotely support this claim.   

Electric is attractive in a number of respects, but it is NOT trouble and maintenance free, particularly considering that you are operating in a corrosive environment.  I've given it a lot of thought and read a lot about it myself, but the more sales pitches I read, the less convinced I become.    I'm contrary by nature it would seem.   I like to let someone else pioneer, and make all the mistakes, and discover all the flaws.  Unfortunately you can't always believe what people say even if they've been through it personally.   Misery loves company it seems.   
     I look forward to your testimonial..........there are few of them out there.

                                                  H.W.

Look at how many times we've all seen or heard about folks having engine problems.
With electric there's virtually no maintenance when compared to a diesel engine.
A couple of electric boaters on the Yahoo Electric Boat forum have had the same battery bank for 8 years.
James @ Electroprop has two solar panels on his boat & claims he can motor all day @ 3 knots on sun power alone.

I think in the long run going electric is not any cheaper than a diesel repower if you're a DIY. The good thing about it is you start out with a basic system & you can add from there as finances allow. Solar, Honda generator, bigger/better battery bank, you get the idea.

[SeaHusky]

I was thinking in the same lines as Owly above but about the Honda 2000. I thought about doing a diesel/electric setup but realized it wasn't practical. 2000W gives you roughly 2,5hp. A larger generator with more power would end up being larger, heaver and more expensive then the 16hp diesel that I already have and would still need the same maintenance.

What does "Beke" mean anyway?

[Cyric30]

What does "Beke" mean anyway?

IIRC, Their boat originally came with a Westerbeke diesel, or they where putting one in before they decided to go with the electric setup, hence the adopted name of Electo-Beke. again IIRC

[Bob J (ex-misfits)]

The one thing I've learnt doing mechanical design & engineering work for a living, the numbers that come out of the calculator never lie, only the people that enter them do. So it's pretty hard to blow sunshine up my backside. Without any doubt some of the claims made by some EP vendors are unsound.

Capt. Mike from the Bianca is beginning his 8th season on his original AGM battery bank, he's not an EP vendor.  James from Electroprop is a vendor. I don't know the specifics on his solar system but don't know why anyone would lie about something like that. The old saying bad news travels faster than good, he'd be called out in a heartbeat if it was BS & lose credibility. Recently on the Electric Seas web site one person reported a 40+ mile run on their system. But they have a 1000 AH battery bank turning two electric drives & discharged the bank down to 16%....

The reason UMA calls it an Electro Beke, they saved the transmission from the old engine & hooked it up the electric drive. IMHO, the efficiency loss turning a big ass gear box doesn't make sense.

For me, I know what I'm not going to do & that's install another diesel. If I decide to go with an EP drive instead of an outboard, it just becomes another one of the many science experiments I've conducted over my lifetime & I'm OK with that. If it works & meets my needs great, if it doesn't I'd be the first to say so.

[Bubba the Pirate]

I'm likely to try the EV experiment and will report the details.

[CharlieJ]

Should with me- first time as radioman on C 54, Iceland to Continent.  1960. Landing Prestwick Scotland. Broke out of clouds at about 500 feet. 40 souls aboard. Nervous? oh Yeah.

[CapnK]

WRT battery age: I've a pair of gel cell batteries (*not* AGM), it's been ~10 years or so since I took them off of a Hans Christian. The boat had been put on the hard & For Sale a year or so earlier after cruising, so they are likely 12 years old, or older, since new. The new owners went with T-109's when they outfitted the boat, and I got the gel cells in return for some totin'. :)
They've been the house bank on Katie, hooked to a solar panel for the past 9 years (best guess), used only occasionally to power LED's, bilge pump, Caframo fans, and the Engel on occasion. No use calling for deep disharge, IOW, so ideal conditions for long life from a battery.
There were 3 of these batteries, I gave one to Capt. Smollet when they still had their A30 here, and a concrete date for that which I can find here on the Forum was back in 2007. So there's some provenance. :)

The Trojans here on Melelani are shot, so I took the gel cells from Katie a week ago today, and they have been sitting in the cockpit waiting installation (today). I wanted to let off any surface charge to check voltage prior to installing. While these have not been load tested, after sitting for a week with no charging input, both are showing right at 12.9v on my digital multimeter, which is spot on for gel cells. We'll see how they do this week after I test them some, letting them run systems.

[Owly055]

WRT battery age: I've a pair of gel cell batteries (*not* AGM), it's been ~10 years or so since I took them off of a Hans Christian. The boat had been put on the hard & For Sale a year or so earlier after cruising, so they are likely 12 years old, or older, since new. The new owners went with T-109's when they outfitted the boat, and I got the gel cells in return for some totin'. :)
They've been the house bank on Katie, hooked to a solar panel for the past 9 years (best guess), used only occasionally to power LED's, bilge pump, Caframo fans, and the Engel on occasion. No use calling for deep disharge, IOW, so ideal conditions for long life from a battery.
There were 3 of these batteries, I gave one to Capt. Smollet when they still had their A30 here, and a concrete date for that which I can find here on the Forum was back in 2007. So there's some provenance. :)

The Trojans here on Melelani are shot, so I took the gel cells from Katie a week ago today, and they have been sitting in the cockpit waiting installation (today). I wanted to let off any surface charge to check voltage prior to installing. While these have not been load tested, after sitting for a week with no charging input, both are showing right at 12.9v on my digital multimeter, which is spot on for gel cells. We'll see how they do this week after I test them some, letting them run systems.

     Batteries that are deep cycled do not tend to live very long.   I have a huge liquid lead acid battery........ twice the length of a normal battery, that I scavenged from a combine years ago on my 3 yard Allis Chalmers 645 loader that is about that age, but it's about end of life.  It gets used for starting a diesel that starts easily, and nothing else, and never has been used to start it when the weather is cold.   But I keep the battery on a pulse desulphater for extended periods of time, and on a float charge in the winter.   
     Most people use garbage batteries.... the so called "marine deep cycle" batteries that are often just a starting battery with a different label and screw terminals.   Everybody who's using gel cells or AGMs on their boats, please raise your hands  ;-)   You can't beat well maintained good quality golf cart batteries for the price in a battery bank.
                                                H.W.