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Installing an electric motor

20K views 84 replies 29 participants last post by  SailingCinderella 
#1 ·
Has anyone installed an electric motor in a boat that originally didn'y have an inboard? It's just an idea but I was curious I anyone had done it. I have a Helms 25.
 
#2 ·
it has been done, and for most it is still not a cost effective change. Quite a bit of work on all fronts and you need to have room for batteries, controllers and electrical. New engine bed/frame and copious small items. If you have a yard do it, the cost will be even more. Low voltage and high current needs to be respected in every way.

best of luck.
 
#4 ·
I'd have to disagree after doing the first test run on a friends electric motor install yesterday.

The boat is an older O'Day 28 and he pulled the diesel and replaced it with an electric motor over the winter. He's an engineer and did his homework on purchasing a kit versus sourcing all the parts himself and went with an off the shelf kit. Total cost including batteries was less than a comparable Beta Marine diesel.

The engine and batteries weigh less and take up less room than the diesel and fuel tank. The controller is mounted in the cockpit where the old throttle control was located. He did modify the engine mounts and construct a battery box from 3/4 ply. None of it was beyond a "do it yourself" sailor.

Estimated running time at cruising speed (not full throttle) is about four hours. We couldn't test that "normal" running time yesterday as there was a lot of chop on the bay. Performance was brisk. Docking will take a little practice. We're all used to the slight lag as an engine revs up - with the electric the power is right now, there's no lag.

Whether electric makes sense for you really depends on how you sail. In his case it's 15-20 minutes motoring from his slip until he can raise his sails. His sailing is strictly day sailing on the bay and he can plug in and top off the batteries each night in his slip -- which is how many of us sail anyway.

It wouldn't be the right solution for someone running up and down the ICW, but we have passed the tipping point where electric is a viable option for many weekend sailors.
 
#9 ·
Whether electric makes sense for you really depends on how you sail. In his case it's 15-20 minutes motoring from his slip until he can raise his sails. His sailing is strictly day sailing on the bay and he can plug in and top off the batteries each night in his slip -- which is how many of us sail anyway.

It wouldn't be the right solution for someone running up and down the ICW, but we have passed the tipping point where electric is a viable option for many weekend sailors.
Jim:
I agree that just needing 15-20 minutes to leave the dock is a no brainer for electric propulsion. But, I disagree it's not viable for trips like the ICW. I cruise the same as when I had my diesel. But, when I do need to motor for an extended period of time having Electric Propulsion offers flexibility to operate in a hybrid mode for very little cost. I've done forty mile trips when there was no wind under electric propulsion alone. A couple of hours just using the battery and then firing up my Honda 2000 generator when needed:
THE BIANKA LOG BLOG: ELECTRO SAILING AROUND NEW YORK: PART ONE
The quietness of the operation of EP makes long motoring much more pleasant than the diesel days for me.
 
#3 ·
We did the opposite and used an electric outboard after removing the old Atomic4. Check out Ray Electric Outboards. They are incredibly well built. We've cruised Mexico with it for a couple years in a 35' 15000# boat. We bought the most powerful model, they have several, all different voltages, etc. Would be much easier than a retrofit... FWIW. Good Luck, we love being electric.
 
#5 ·
I converted to electric propulsion back in 2008 but, I replaced an inboard 27 HP Westerbeke diesel. Though last year I did spend a great afternoon on the Columbia River with a fellow who converted the original Tohatsu outboard on his boat to electric. It was mounted on a Columbia River Scow originally built by Sam Mckinney:
THE BIANKA LOG BLOG: AN AFTERNOON ON THE COLUMBIA RIVER ON AN ELECTRIC SCOW
 
#7 ·
Most of the install would be the same, actually easier since there is no old engine and charging system to remove - the kit included AGM batteries and a charger.

The addition of a shaft log and prop strut would be required. They could come from a comparable sized donor boat or can be ordered online. This shaft log fits the Catalina Capri 26 for around $50 and would work. This bronze strut assembly also from a Capri 26 would work for around $570.

The fiberglass work should be doable by someone with good DIY skills and a sawsall :grin or you could farm that job out to the yard.

I just don't see it as that terrible a job on a 25 footer.
 
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#8 ·
@hellsop is correct, the boat never had a inboard. It was never designed to have one. My thought on this idea was to have solar panels to charge the batteries to run the motor. But again, its just an idea. I have a 8hp outboard to use and I'm guessing that if I ever go any distance, that it will suffice. I'm not trying to circle the globe. but maybe a trip from Texas to the Keys one day.
 
#67 ·
I know the Torqueedo is supposed to be a very nice set up. I believe there are other electric outboards (other than trolling motors) but the Torqueedo seems to have a very nice system including charger/battery and what not. They seem expesive, but when you factor in all that has to be done to make one from scratch they really start looking like a bargain.
 
#10 ·
Electrics have a lot of advantages over diesels. There really are only two big disadvantages.

1) Range is expensive. Batteries aren't cheap, and if you're using lead-acid, you're going to need to make sure you have the space and weight for them. The flip side of that is that electricity IS cheap, compared to gas or diesel. Also consider that lead-acids need to be replaced every 3-7 years, depending on use. Lithium-iron-phosphate batteries (LiFePo4) have a lot of advantages over lead-acid, such as lasting 10-15 years and being much lighter, but they currently cost a lot more.

2) Charge speed. Lead-acids in particular are VERY slow to charge. LiFePo4s can be charged a lot faster on shore power, but it still takes a few hours on a standard 30A 110v cable, assuming you have a powerful enough charger.

In short, it's much harder to take a long trip under power with an electric boat. If you're just sailing the bay, it'll be fine most of the time. I'd make sure your seatow membership was active just in case. :D
 
#12 ·
Batteries aren't cheap, and if you're using lead-acid...
He's using AGM's and I think anyone going electric would go AGM as well. They seem to have the best bang for the buck right now. Lithium's are still very expensive.

These new Carbon Foam batteries from Firefly may change the equation in a significant way if they turn out to be as good as they look at first blush.

I'd make sure your seatow membership was active just in case. :D
That's good advice whatever motor you're running :wink
 
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#16 ·
Sure I've got a 30 foot sailboat and that is how I prefer to propel it. But, there are times when the wind dies or never arrives. I went through a lot of what if scenarios back in 2007 when I first started thinking about the conversion to electric. My plan A was to see if I could also use a backup generator if I needed too. But, I did not want to install another diesel engine (marine generator) below decks if I could avoid it. I had enough squeezing my 6 foot 2 inch frame through the hatches to maintain the one I removed. That's when I hit on the idea of using a lightweight Honda 2000 not only to charge the battery bank(s) but, also to power the electric motor when needing to do extended motoring. I found my plan A worked very well. I can fire up the generator and motor until I run out of fuel without drawing down the battery bank. Because I am only using a 900 watt charger/power supply I actually operate the generator in ECO mode. One gallon of fuel actually lasts about four hours. Usually I will just use battery power to get out of the harbor but, after several hours if their are no winds or they die and it looks like it will be awhile before they return I just fire up the Honda and operate in "Hybrid mode" using the power from the generator to turn the electric motor preserving (and sometimes simultaneously charging the battery bank) when underway. Of course I can still tap into the battery bank if I want to use a few more amps anytime I want also. Also it is much quieter and there is less vibration than having the diesel under the cockpit. I hope that explains how I operate my system when the winds don't cooperate.
 
#17 ·
When you get to that point - down to the Keys, you might be passing right by us. Hopefully we will be in the water by then. In west central Florida - Spring Hill. Will put in at Hernando Beach. Have to fix our keel first, wondered why we kept finding water in the bilge on dry land and covered. Made an exploratory surgery and found this: see pic below
 

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#21 ·
After 2018, when the new sub $35K price - 200+ mile range BMW, Chevy, Nissan, Tesla, Toyota, etc. are on the market in full I would expect there will be tens of thousands of 85 mile range cars for sale dirt cheap. The batteries, charging systems and motors will still be useable. I wonder if any will find their way into sailboat applications.

I don't know how my Leaf's 100 mile range would factor into pushing a sailboat at hull speed but I'll bet its far enough to get the vast majority of us to the next port while running the radar, chartplotter, stereo and air conditioning.

Things are moving fast.
 
#22 ·
At hull speed it's probably enough to get you 10-12 miles give or take. It isn't exactly hard math...

Leaf battery pack -24kw
Leaf usable capacity - 21.3

C&C 30 installed power - 15kw
Power used at hull speed 75% (?)
Power used at hull speed 11.25kw/h

Run time at hull speed - 1.89 hours
Hull speed C&C 30 -6.67kn
Range - 12.6nm.

This of course assumes a 100% efficiency engine, clean bottom, no wind, no waves, and lightship. But if it's far enough it should be fine.

Just keep in mind that it is going to take a while to recharge. If you plug in a 100% efficient battery charger, into a 30amp plug (3.3kw/hr) it's going to take you 10 hours to recharge the batteries. If you want to use solar panels... It's going to take a couple of days.
 
#23 ·
It will be interesting to see how the used market progresses. There are people buying wrecked Leafs, etc and using the components for ev conversions. You can get a lot of hardware relatively cheaply.

I think the math above is missing part of the equation, a Leaf's 24kw battery is at 360 volts, a typical marine ev system is 48 volts.
 
#26 ·
I'm pretty sure the amp hour capacity of a Leaf battery broken down into a 48 volt pack would be 500 AH's. Seven years ago when I installed an electric auxiliary in my Ericson 27 I motored 5 hours at 4knts and used just over half of my 200 amp battery capacity. These days I know I get far less then that.
 
#29 ·
An electric sailboat is a far, far simpler beast than an electric car. Far lower power output required, just one motor, a smaller battery pack, etc. Most kits I've seen use a sevcon 4 controller, some sort of pancake motor, a reduction gear, and an electronic throttle. Just add batteries of your choice.

Unless you plan to own your boat for a very long time, lead-acids are still your best bet for batteries. Sam's Club sells group 31 AGMs for $179 each, and that gives you about 1.1kWh per cell, so a basic 48V 4.4kWh group is $716, or $162/kWh. I have yet to see any other battery chemistry drop anywhere near this price point. Even if you stick with a hard 50% discharge cutoff to maximize your battery life, you're still looking at a usable 2.2kWh or $325/kWh, which is still lower than the cheapest LiFePo4s available today.

Once lithium batteries are close to the same price per kWh that lead acids are, I think we'll see an explosion of electric sailboats. Why replace a diesel for $15k when you can repower with an electric for $10K and generate fuel while you sail?

Motorboats, on the other hand, will be stuck on dead dino fuel for the forseeable future.
 
#38 ·
I have not found this to be a problem. I've been using an off the shelf Dual Pro 4 charger to finish up the charge cycle after the initial bulk charging. The four batteries in my 48 volt string stay remarkable balanced every time I charge them after that. It acts as a BMS for my AGM's.
 
#32 ·
Hi

I am fairly new to the forum. I am definitely interested in converting to electric on my C&C 27 - but find process of removing Atomic4, and installing new system a bit intimidating. Do Electric Yacht and other vendors have mechanic network to assist? Im in Toronto.

thanks
 
#33 ·
EP is not some exotic technology. For the average marine electronic tech it's nothing they can't handle. It's basically wires, connections and batteries. BTW most boats already use an electric motor on board. It's called a "starter motor". :) With EP you are just eliminating the diesel and replacing it with a very efficient motor.

As far as removing the engine I started out with the help of a diesel mechanic (part of the deal for selling him the engine) because I had no experience in doing it. He actually never completed the job and he never bought the engine. So I decided to do it alone.
THE BIANKA LOG BLOG: Removing a Westerbeke diesel engine
Turns out it was not that difficult and did it all myself. Only needed the yard folks to lift it out of the cabin with the yard crane.

I did use the services of a shipwright for one thing because I needed to extend the motor stringers forward a little because my boat was not a straight line setup but, had a V drive transmission setup. But, that's normal type of work for them. In short there is nothing exotic about an EP installation that if you are handy or a boatyard can't handle.
 
#34 ·
Thanks Mike

That helps a lot. My rough plan would be to yank the A4 using the yard crane just before haul-out, and install the electric on the hard. Gives me all winter to tinker.

What reputable electric kits are out there? I have info from Electric Yacht and they look very professional. Others i should consider?

thanks again
Steve
 
#35 ·
Yeah doing things on the hard is much easier for engine removal and the install. I recommend it. At least the boat is not being rocked by Yahoo power boaters creating wakes. The hardest part will be removing the old engine and cleaning up after it. :) Back in 2008 when I converted there were not a lot of choices for EP systems and a some were just small part time garage operations. That has changed over the years. Electric Yachts have been around for a few years. My Thoosa 9000 is distributed by E-clean Marine out of Annapolis and they have dealers around the U.S.. There are others but, I do not keep up on them since my system has been so trouble free since the install I hardly ever think of it after eight years.
 
#37 ·
Hi Mike

can you point me to a forum link that discusses pros and cons of various battery types. I know that is a very BIG topic but i wouldnt mind reading through various views. and to be pointed, what battery type do you use, and what capacity relative to boat size, etc?

still climbing learning curve... thanks
 
#39 · (Edited)
I think if you do a search for Lithium Ion batteries here or any sailing forum you will get a lot of info and opinion on that subject. Also check out http://batteryuniversity.com/ When I installed my system back in 2008 Lithium Ion was new and expensive and had long lead times for ordering. It was also (is) sensitive to charging voltages. So it required a BMS (battery managment system) that monitored each cell and shut down the charger before any one cell could be damaged. Considering the cost and added complexity required I decided AGM's were the way to go. So I chose four 8A4D AGMs for my 48 volt bank of 210 Amps capacity. I like the simplicity and track record of the AGM. I also thought about replacements while cruising. I could get a replacement AGM in a day or two from a local distributor. Not always the case when you have to match a Lithium Ion cell. Another concern about the Lith Ion complexity is that one or all of the BMS modules could be knocked out by a nearby lightning strike by some induced current in the circuitry. Just seem like too many things that could go wrong to be worth the benefits IMO.
 
#42 ·
If one prefers electric propulsion, for it's "off the grid" capabilities or it's reduced noise, that makes sense.

If they are being used for environmental reasons, they remain highly suspect, but improving. It's great that mbianka got a full life out of their AGMs. The manufacture of lead acid batteries requires about half the energy that they can store over a lifetime. Kill your batts too early and there is no environmental contribution. Since the vast majority (80%) of energy created in the US is carbon based, one is only reducing the environmental impact of carbon by 60%% of their lead acid battery usage, assuming they live a full life. However, in order to gain any environmental improvement at all, you can't plug into shore power to recharge them. That shore based power was also dominantly carbon based. In fact, plug in 100% of the time and you'll be burning more carbon energy than the electricity you use as you have to combine the shore power production and battery manufacturing production. I would think most that use electric propulsion for environmental reasons would avoid shore power and use solar or wind. That's great and is making some progress, but if you don't get a full life from your batteries, you may just be breaking environmentally even.

Finally, battery production also comes with it's own environmental issues, such as post consumer reclycling of acids, plastic casings and heavy metals, along with the rare metal excavation for manufacturing.

Li-ion are substantial better and will likely overcome this issue in time. However, since most of us use lead acid batteries, I suspect most are accomplishing virtually no environmental impact. Certainly my house bank doesn't. It's only charged by shore or diesel motor.

The interesting issue raised in this Stanford article, which I linked to provide reference to the energy required to manufacture batteries, is the discussion of how you store solar and wind generated power on our grid. Carbon power is efficient, in part because of it's energy density, and a stockpile of coal, diesel or natural gas is energy storage. The wind doesn't always blow and the sun doesn't always shine. Therefore, in order to effectively use wind and solar, you have to have separate storage capacity and it's impractical to build that many batteries to do so on a national scale. Reading about hydro was interesting, I'm sure they'll think of others. I'm just not sure how efficient they'll be on our boats.

Stanford scientists calculate the carbon footprint of grid-scale battery technologies

https://www.eia.gov/totalenergy/data/annual/pecss_diagram.cfm
 
#46 ·
If one prefers electric propulsion, for it's "off the grid" capabilities or it's reduced noise, that makes sense.
My reason for converting to EP was because I was &^$* tired of squeezing my body into a confined space to work on a greasy diesel engine. Having spent a season and close to $1000 trying to get the engine to start. I was looking for an alternative to rebuilding or putting in another diesel and luckily the EP concept for smaller boats was just starting to develop. That said I still think EP is better for the environment compared to diesel. When my batteries finally need to be changed most of them will be recycled to make new batteries including a case. The major components of my EP system are a 45 pound motor and a 45 pound controller box. Yes there is energy and materials required to make them. But, compared to whats required to make the thousands of parts that go into the 425 pound diesel I think they are minimal in comparison. Things I sure don't miss is scrubbing the black exhaust mustache off the transom, winterizing and oil changes. :)
 
#45 ·
My electrical engineering skills are pretty nonexistent
Is there a specific reason you use a separate HB. Why not use a voltage converter
https://www.google.com/search?q=48v...droid-samsung&sourceid=chrome-mobile&ie=UTF-8
Couple of reasons:
1) The 12 volt house bank was already there. Part of the boats original setup. If it ain't broke don't fix it was my attitude. The windlass is also connected to it and can draw a lot of power when in use. You would need a big 48 volt to 12 volt converter to handle the load.

2) When I converted to EP back in 2008 it was in the early stages of being able to have EP in mid size sailboats. There were not any boats my size that knew that had done this. So it was a leap of faith for me. I did want to not all my electronics in one basket. I was not sure how reliable EP would be and I wanted to have the ability to operate VHF, GPS etc... without just depending on the EP battery bank. As it turns out the EP system has been very reliable. But, I would still do it the same way today with seperate systems. In fact I sometimes use the EP bank to power some of the 12 volt devices like my two refrigerators after a few sunless days at anchor. Since the 12 volt solar panels can't keep up. The 10kw EP battery bank is just sitting there waiting to be used if needed so I don't even have to fire up the generator.

3) I do have a 48 volt to 12 volt converter as a backup (I sometimes use it for my laptop) and also have a 1500 watt inverter if I want to bake bread or use a 120 volt tool. Though I try to keep the EP bank topped up and ready as much as possible. Since it has both solar panel charging and wind turbine charging. Even if I do tap into it it charges up pretty easily without me having to fire up the generator.
 
#47 ·
Maintenance is a good point. I've got my diesel in parts right now. Not always fun.

However, it's the batteries and how the electricity is made that is used to charge them, that is the environmental question. It's not "cleaner" unless one makes their juice themselves from wind/solar. Over half the electricity coming from the shore power cable (as well as that used to make the batteries) came from burning petroleum or coal. Another 30% from natural gas, which would be less emissions than an onboard diesel, but still has carbon emissions.

I don't begrudge anyone the use of EP. I dispute that recharging from shore based power is all that cleaner given the combined carbon power used to make the batteries and the shore power. I even wonder if an EP aux is used more than a diesel aux, because it is quieter and thought to be greener and cheaper. What do you think?

More nuke power in the grid would be a great idea. Available 24/7, no greenhouse gases, no inefficient power storage requirements. As noted in the Stamford article above, more wind/solar in the grid is hard, because it has to be stored somehow when the sun doesn't shine and the wind doesn't blow.
 
#49 · (Edited)
Maintenance is a good point. I've got my diesel in parts right now. Not always fun.

However, it's the batteries and how the electricity is made that is used to charge them, that is the environmental question. It's not "cleaner" unless one makes their juice themselves from wind/solar. Over half the electricity coming from the shore power cable (as well as that used to make the batteries) came from burning petroleum or coal. Another 30% from natural gas, which would be less emissions than an onboard diesel, but still has carbon emissions.

I don't begrudge anyone the use of EP. I dispute that recharging from shore based power is all that cleaner given the combined carbon power used to make the batteries and the shore power. I even wonder if an EP aux is used more than a diesel aux, because it is quieter and thought to be greener and cheaper. What do you think?

More nuke power in the grid would be a great idea. Available 24/7, no greenhouse gases, no inefficient power storage requirements. As noted in the Stamford article above, more wind/solar in the grid is hard, because it has to be stored somehow when the sun doesn't shine and the wind doesn't blow.
Personally I try avoiding docks as much as possible. A secluded anchorage or mooring is were I prefer to hang out on. Yeah charging at the dock only offers faster charging times due to the amps available in the grid. Even on those rare times I do tie up to the dock I often forgo the electric hookup. Really find there is no need to pay $10 to $20 a day for the amount of power I would use to charge the battery banks when my solar panels & wind turbine can keep things topped off. EP works well on a boat as you point out because the storage excess energy is already there in the battery banks. On a grid based systems storage is the problem as the article pointed out. In converting energy there is always some losses. Though I'd have to say out of the fossil fuels natural gas seems like the most useful for grid energy production since the only it becomes useful when you burn it. Oil has other many other uses besides burning. I still think grid tied solar is useful even without a good storage solution. Since it is available when there is most demand it means utilities need to smaller fossil fuel generation available like peaking generators. Even without being connected to the grid solar is useful. From my experiences on my boat I have incorporated a whole house lighting system using some spare solar panels:
THE BIANKA LOG BLOG: WATTS GOING DOWN ON LAND AND SEA
Every room in my house is lit from dusk to dawn using solar charged power. Which means I never have to put on a grid tied light to walk around the house at night. My neighbors were jealous after hurricane Sandy thinking I was the only one in the neighborhood with power. :)

I probably do use my EP more than the old diesel but, I use it differently. For example I my start out on a cruise in the morning in very light winds. So I just crank the EP control until I'm drawing 10 amps or so. This completely eliminates any prop drag. Giving me a nice bump up in speed without having to buy a folding prop Which would be more dollars out of my pocket and maintenance. Since EP is so quiet it's pleasant as sailing. As the wind increases the amp draw goes down until a certain speed the prop actually starts to recharge the battery bank. I have also used this same procedure when I wanted to avoid an extra tack to get into a channel or under a bridge. Just a few quiet amps and I'm able to point up enough to clear the point I want to pass without tacking the boat. The nice thing about EP is you don't use energy until you need it. When you fire up a diesel you are burning fuel whether you use it or not. Most people fire the diesel up way before they actually put it in gear. With EP you turn the control an go until then your energy demand is almost nil.

Good luck with the engine work. Brings back bad memories of me working on the Westerbeke diesel. I did sell my non working diesel to a fellow who rebuilt it himself. He spent about $3500 in parts and got two years of use out of it before he replaced it. Glad I did not go that route because I would have had someone else do the work and it would have been even more expensive!
 
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