# Electric Conversion



## andrewoliv (Sep 22, 2011)

I am considering re-powering my boat (Mariner 28). The option of converting to an electric drive (Elco) is very appealing. However, I would like to hear from anyone who has an electric drive on their boat. Pro's and Con's.

I am concerned about power into a strong headwind or current. How well does solar or wind re-charge the batteries. Length of time is also a factor.

I cruise the Chesapeake so don't plan to run the motor for 8-10 hours straight. But what is a realistic length of time to run the motor at a comfortable cruising speed? 5-6 knots on a boat that displaces 7500 lbs?

Any opinion welcome


----------



## LakeSuperiorGeezer (Oct 8, 2010)

I took a look at the Elco website: Elco Motor Yachts and this is the recommenced installation for your length of boat. From the above it looks like you are good for 6 to 8 hours at 5 knots. What concerns me is the installation is 1000 pounds. What is the maximum recommended weight your sailboat will take? Include weight of crew and provisions. There will also be a replacement cost for the batteries in five years if the batteries are carefully maintained. If the batteries sit discharged for several months, then replacement will be needed immediately.


----------



## JedNeck (Sep 22, 2011)

My opinion would be to wait until the next time you repower your boat to consider electric. The technology just isn't "there" yet. You and the next person that buys your boat will be range limited. Batteries are heavy expensive and dirty. Solar panels and wind won't charge quick enough for back to back days and the panels needed will eat alot of precious deck space. 
You're not saving the enviorment...you will have something fun to talk about...but ultimately it will be a liability to work around. 
IMO you would be better off buying a large electric outboard and a few deep cycle batteries. It will be lighter, easier and you will still have fossil power in a storm or long calm for safety.


----------



## kd3pc (Oct 19, 2006)

you might google - Nigel Calder, as he has been tasked with designing and implementing a true electrical propulsion system and documenting the advantage or disadvantage. A year back, electric was not there yet, in any commercially viable way and I think that is still the case. This was with the best and most advanced technology money could buy. As the Elco drive is "old technology"...

He is a genious, IMHO, and has the skills and credentials to do this.

I think that given the weight, cost and installation issues that you will encounter in bringing this to your Mariner....it will be a no-brainer to NOT do it. It is not a trivial task, and few yards or techs are on the Bay that know anything at all about to help you.

That being said, if I had the money to test this, I would be all over it, just to see for my self how it plays or doesn't. I would contact Stevens Institute (or other engineering college) and hire two or three interns with an interest to help.

Keep us posted as to what you learn.


----------



## andrewoliv (Sep 22, 2011)

I have to re-power now. I am replacing a Yanmar 2QM15 with a 2YM15. Looking at the electric drive as an alternative.

I agree. From what I have read so far I am suspect of the electric drive. I am hoping to hear from someone who actually has one and get some "real-world" feedback.

The specs on line in the brochure are most likely based on perfect conditions. So I tend to adjust the specs published downward. (reduce the time and speed).

I do not take the solar or wind re-charging seriously, but I cruise on the Chesapeake where shore power is readily available.


----------



## andrewoliv (Sep 22, 2011)

kd3pc said:


> you might google - Nigel Calder, as he has been tasked with designing and implementing a true electrical propulsion system and documenting the advantage or disadvantage. A year back, electric was not there yet, in any commercially viable way and I think that is still the case. This was with the best and most advanced technology money could buy. As the Elco drive is "old technology"...
> 
> He is a genious, IMHO, and has the skills and credentials to do this.
> 
> ...


Very good information. Thanks!


----------



## Donna_F (Nov 7, 2005)

kd3pc said:


> you might google - Nigel Calder, as he has been tasked with designing and implementing a true electrical propulsion system and documenting the advantage or disadvantage. ...


Calder's 45' boat more easily carries the extra weight involved with the hybrid electric propulsion system he installed.

We are also considering an electric drive since we have to repower anyway. The weight is an issue that is swinging the pendulum back to diesel.


----------



## Mark F (Mar 7, 2006)

Hi Andrew,

There are plenty of Electric Auxiliaries out there. I installed one in my Ericson 27 three and half years ago and have been completely satisfied. This is a link to a blog that I started recently; Ep - Blogs - EY.o Information Exchange there are four parts so far. It will give you an idea of the setup and limitations of the design.

Here are some Marine EP manufacturers;
Electric Yacht - Electric sailboat propulsion systems that are cost-effective, yet CLEAN, GREEN and QUIET!
ThunderStruck Motors - Electric Sailboat Kits
ASMO Marine
Electric | Propulsion Marine


----------



## SMReuther (Jan 30, 2002)

*Electric propulsion*

Hi Andrew,

Actually, there are quite a few electric boats out there happily cruising both inland, coastal and beyond. Check out the various companies that offer systems. There are the more "do it yourself" systems if you are handy and really want to be adventurous, or the "drop in type" systems that can still be installed by you to save a bit on costs, but have already been setup for you so you don't have to re-invent the wheel. Mark mentioned several companies (ASMO Marine does have a U.S. distributor in Annapolis). MasterVolt also has systems.

The Elco system at 1000 lbs seems quite heavy - unless they are suggesting a dual battery bank. A 48volt system with 4, 210ah thin plate AGM's should weight pretty close to the weight of your motor, plus the transmission and full fuel tank.

If you want to read about someone who switched 4 years ago and is more than thrilled with his electric propulsion, check out Capt. Mike's blog:
THE BIANKA LOG BLOG: Going electric: Part 1: The why and how

Electric propulsion is here, it is a viable option for a sailor, and if you are ready to enjoy it then there are many options, and people out there who will help you with the conversion. Cruising the bay as you have described is the perfect use for electric propulsion and if you want to increase range you can always carry a small, portable generator (see Capt. Mike's blog above).

Good luck - if you do decide to convert to electric, you will be happy you did. It makes being on the water even more enjoyable.

SMR


----------



## Cruiser2B (Jan 6, 2011)

There was a very good and interesting article in _Good Old Boat_ a few issues ago about an electric drive system that the owner himself made. Article says he can cruise up to 3-4hours at 4.5kts and 7-8 at 3ks if i remember correctly. it was in a 27 ft full keel boat, article listed all parts used and total investment was @ $2k. Owner also stated with extra battery storage he culd go further..obviously, but he also was on the Ches Bay and it suited him fine. I will see if i can find it and let you know what issue.


----------



## DamonVT (Oct 22, 2009)

Hi, the article Cruiser2B mentioned is in the May/June 2011 issue and is by Joe Steinberger. His DIY system was rather different than the $$$ systems Practical Sailor covered around the same time.

Aside from the resources mentioned, the listserve electricboats : Electric Boats is full of information and has many people who converted their boats, who sell the systems, and those who are just learning about it.

I think the biggest factor is the range you need. If you need ~100+ miles fuels can provide, electric is out of the question. If you only need a few miles, a low cost system like the one in GOB could do it. Electric motors have enough _power_ for short bursts through inlets, but have trouble storing enough _energy_ to run for long periods. That said, if the range works for you, which it could if you don't spend time in narrow rivers and channels and have some patience and flexibility, electric offers a lot of advantages such as: silent operation, no trips to the fuel dock guesstimating fuel so as to have enough but not having it grow old in the tank, no antifreeze or oil changes each season, and potentially extra space where the motor, transmission, tank, exhaust, and water intake used to be, and to repeat that last one, you get to remove a hole from the bottom of you boat 

I've just put a deposit down on a system for my Ranger 33, and am going to fit the batteries in with the electric motor where the old A4 was. I suspect it will weigh about the same as the old system, but with the weight near the center of gravity and none out under the helm seat where the old fuel tank was. It's been helpful to have a friend who converted his boat last spring. See if you can find a local on that electric boats listserve. I highly recommend searching the archives and asking questions there.

Best of luck!

Damon


----------



## jepomer (Nov 29, 2008)

There are many "naysayers" who have no real experience with an electric re-power conversion. Those who have made the conversion are most always very happy with the choice. The commercially available kits are sized for a wide range of length and displacement hulls. This takes away the "experimental" part of the re-powering project.

The properly sized electric conversion will handle winds and seas as well as any gas or diesel powered boat. Don't forget that most of the very large vessels at sea use electric motors as the final drive. 

This past season I used a Torqeedo 2.0 Cruise model on my Capri 22. The previous season I used a Nissan 5 HP 2-cycle outboard (equivalent "sizes"). I had much more control at all speeds and instant on power with the Torqeedo. I could get to hull speed (6 knots) except against the strongest winds (25 knot winds) with both motors. I could motor sail all day and still not exhaust (got to 80% depth of discharge) my 225 amp, 24 volt battery bank.

Most of the time, I used the electric motor to maneuver in and out of our slip and through the mooring fields. Solar panels will replenish that energy use quickly. Since we had electricity at the slip, the batteries were always at full charge when we left the dock. 

Next season we will move this Torqeedo to a Cape Dory 25 and will be on a mooring with solar recharging. We will have a small generator available for those few times when the solar recharge or the distance to travel requires a bit more.

My wife and I sail for the quiet. The electric motor auxiliary adds to the relaxation with quiet on-demand power. We can enjoy conversations at normal levels. All guests who come with us remark how much they are impressed with the setup.

Oh yes, you will probably "sail" more since you know you can turn on the electric motor instantly and then turn it off until needed.

John


----------



## tommays (Sep 9, 2008)

Well so far in this round the boats that make any distance seem to be a hybrid type as they carry some type of generator which sort of defeats the point to me as you still have to keep a motor running


----------



## jepomer (Nov 29, 2008)

tommays said:


> Well so far in this round the boats that make any distance seem to be a hybrid type as they carry some type of generator which sort of defeats the point to me as you still have to keep a motor running


Are you "sailing" or "motoring"?

If sailing with an electric motor which is rarely used, a generator is not needed. The batteries can be topped off with solar or wind.

If motoring everywhere, why bother with sails?

It really depends on how you choose to travel. The original poster sounds like he wants to sail mostly, but have a backup or auxiliary. Electric will do that.

John


----------



## kd3pc (Oct 19, 2006)

jepomer said:


> Are you "sailing" or "motoring"?
> 
> If sailing with an electric motor which is rarely used, a generator is not needed. The batteries can be topped off with solar or wind.
> 
> ...


Even on the Chesapeake, with decent wind almost all the time blowing some direction, motoring is a needed thing. Sometimes in an emergency or to avoid.

So as much as I love to sail, in the real world motoring is happening quite a bit.

Electric MAY do that, or may not...depends on budget, size of boat (not a DIY on my 42') even if I had the money, currents, how far up the creek you berth or moor, etc, etc.


----------



## Ajax_MD (Nov 24, 2009)

I live near Annapolis, and for a few years I drove a 1974 Beetle converted to 100% battery-electric drive. I put 10,000 miles on it, and it topped out at 70 mph, with a 35-40 mile range depending on where I was driving and how fast.

Even though I'm an advocate of electric propulsion, I am a realist about it's costs and limitations. Here's what I have to offer:

*Energy storage or cost is the limitation*. You can easily afford lead batteries, but they are heavy and don't store a lot of energy. Lithium batteries are available and comparatively store a lot more energy for their weight, but are very, very expensive and require complex monitoring systems to prevent damaging them during charging. A wind turbine and/or a solar panel or two will help you recover a little energy in a day or so, but not totally re-charge. You'd have to completely upholster your deck to get that kind of power. In order to have a bank that gives you any appreciable range, you HAVE to have access to shore power (or not use the motor for a week of solid breeze and sunshine).

I do agree that _in the sailing environs of the Chesapeake_, electric drive is practical. A marina or gunkhole is always a short hop away. If your sailing skills are up to snuff, it can be a way to go.

Something to consider: Yeah, things are close by in the Chesapeake, but we also have long periods with little to no breeze that can cause extended periods of motoring. You'd better have a good suit of sails, tailored for light air sailing, and not be afraid to fly a spinnaker, and you'd better have flexibility in your schedule.

Re-powering with electric propulsion isn't like switching from gasoline to diesel. It requires a little additional preparation and forethought, but it can be done, and in some instances, should be done.


----------



## Coincidence (Apr 22, 2011)

*Electric technology is "there" for many people*

I'm surprised by the number of people voicing a resounding "No" in response to your electric repower question. The technology is "there" and is becoming more and more popular the more people get acquainted with the notion. Boat manufacturers are making electric power as an option on new builds, and a viable one at that.

There was a thread on Sailnet about electric conversion, unfortunately it has a misspelled word--it is titled "Calling all electic drive boats". I encourage you to read it, then I encourage you to engage in one on one conversations with people who have done similar installations. Then you can start talking to electric motor companies.

I just finished up my first season with my electric conversion on a Victoria 26. I had the same reservations--power equivalency with the OEM gas motor, range of batteries, etc. The more I talked to people who went through conversions themselves, the more comfortable I got with it and decided to take the leap. Marine propulsion of any sort has its pros and cons--you yourself will need to determine what will work for you. An electric system has made my boat more enjoyable, I may not think so if I had to make a transatlantic passing.

The beauty of it is this: electric motor technology isn't going to change much in the next decade. Battery technology will. Sure you will have to spend money replacing batteries (I saw someone estimate 5 years--that is generally under heavy use/abuse--AGM batteries are good for 1000 cycles), but other maintenance costs are next to nothing compared to an internal combustion engine. So most of the concern with electric motors are battery related (weight, range, lifespan, etc)

A detailed blog documenting my repower can be found here Coincidence - Victoria 26. Feel free to email me directly if you want to talk more.

Eric


----------



## arf145 (Jul 25, 2007)

tommays said:


> Well so far in this round the boats that make any distance seem to be a hybrid type as they carry some type of generator which sort of defeats the point to me as you still have to keep a motor running


I can see an advantage to a "hybrid" setup over a new diesel engine, even if this means running a motor now and then. With a small generator like a Honda as the emergency recharger, you've got an electric setup that works now, and most days you wouldn't be running a motor. As battery improvements come down the pike you can take advantage of them. Meanwhile, the Honda generator is a movable component that can be used elsewhere or sold if you don't need it anymore.


----------



## mgunning (Dec 17, 2010)

*Repower marnier*

As a disclosure, I am in the business of selling electric propulsion. 
I have come to the conclusion that just about all the EP systems from full product companies work. Your boat would be easily propelled by an electric system which is correctly balanced with the right prop, right motor, and the right battery system coupled with your understanding of the advantages, nature, and limitations of power storage. I do have concerns about those who use the parts catalogue and do not have someone who is experienced or the engineering and build experience to assemble their own.

I believe the key is being willing to go slower - 3 to 4 knots is where you need to be. Develop the skill of motor sailing so that you can go farther, point better, jib better, and go faster with apparent wind. We have a growing number of users in Southern California and I suspect the same is happening on the East Coast. I would recommend you visit the Yahoo Group as I have read many very well presented discussions on electric propulsion. I have noticed that a number of Yahoo Groupers have shared their thoughts and that the general thinking of those who have converted is positive.

Do not count on too much power from solar or wind generators. They are good but limited and most useful when you have your boat on a mooring or at anchor. Regeneration in as small a boat as yours is limited.

Take a deep breath before you buy and get ready to enjoy the truly enjoyable additional sailing capabilities.
Mike 
Electric Yachts So Cal


----------



## Donna_F (Nov 7, 2005)

It sounds like there are two lines of argument here: One about whether electric propulsion is a good idea, the other about whether it's a good idea _on the Chesapeake_.

I joined the Electric Boat Yahoo list yesterday and noticed that someone put out the alert about the electric motor threads on Sailnet. So we have everyone with electric motors extolling their virtues regardless of where the sailboat is located and how it will be used, everyone without electric motors saying they won't work and the technology has not had time to be really tested. Rarely an unbiased middle ground.

As I've said before, we too are considering electric. We've looked into every corner of it off and on since we bought our boat and extensively for the past two weeks trying to make it work for us. Right now I'm considering going with diesel only because of the nature of the Bay. We go to quite a few anchorages that are located up rivers. About half the time it is not possible to sail. Returning from the Annapolis sail show to Rock Hall, even if our transmission had not been near death, there was NO wind in the middle of the Bay and we couldn't sit there for a day or two waiting for it. We could go hybrid but the weight is a setback for our size boat. So, if we limit ourselves to just those anchorages located at the mouth of the tributaries, we're missing an awful lot of what the Bay has to offer and why we chose to keep our boat here.

It's almost like when we mentor new sailors to buy the boat that's appropriate to where they will sail. I need to take a breath and determine if electric propulsion will allow us to get as much out of the Bay as we can. As of now, I don't think that it will with the time we have for each trip. If we were retired and didn't have to be at work on Monday morning, that would change things.

I get that electric is possible. I get it's advantages. We absolutely love the idea. But right now in it's current form it just may not be the most appropriate means of power for the location in which we sail and we have to make a decision based on what is practical and what will allow us to enjoy our boat in the way we intended when we bought it. It does the electric motor industry a disservice by having folks screaming that it is the right way to go for everyone rather than just putting the facts out there and letting people make an informed decision.


----------



## WDS123 (Apr 2, 2011)

We have installed some 575 electric drives on boats since the early 1990's; which is arguably the most experience of any manufacturer.


Here is the skinny: 

1) for boats under 4,000 lbs; pure electric is a very compelling proposition. If it was my boat, I'd always use electric in anything under 4,000 lbs. 

2) for boats over 7,000 lbs; one has to be very clear about one's requirments. A typical range is going to be 90 minutes at hull speed and 3 hours at 1/2 hull speed. This ranges can be significantly extended motor-sailing. These ranges and also be significantly decreased in heavy weather. 

3) hybrid systems, at this stage, work fine but tend to be pricey and the user should have a reasonable technical understanding of the system.


----------



## SURV69 (Feb 2, 2008)

*These are sailboats*

I had always been under the impression that if I wanted to get there fast to go with a power boat and pay through the nose in order to go that fast.

Sailing is not really a "speed" thing for cruising here and, there and, seriously, most sailors don't actually sail anywhere . . . they generally go out for a few hours and come back to their dock(and shore power) nightly to enjoy the other aspects of sailing.

I get no thrill from traveling 6+ knots under power, but I might actually get a "little" thrill traveling 3 knots with electric and as far as going 100+ miles, well with a truly oversized motor 100 miles will still take almost 15 hours travel time with no slowing down and no stopping . . . at 6 knots a hull-pushing(inefficient) speed.

In general, even though cruising in a sailboat is not really a "speed" activity, it seems to be the numeral-uno topic when it comes to electrifying . . . that, along with an overly expectant minimum distance range.

Of course even when I sail over 30-40 miles, I rarely motor more than a few miles . . . and when I motor, I generally target about 3-4 MPH, or about 3knots. Most sailors don't even go out if there's not enough wind to at least push the boat forward maybe a couple of knots.

I wish there were more discussion on the advantage of instant power with instant torque when needed, along with how long that "instant" power and torque might be needed and more discussion on how long an electric engine might power a sailboat at an efficient speed of 2-3 knots, which might actually be sustainable with solar panels through the length of a sunny day. Let's not talk about the inefficiency of ICE, the high RPM's needed to experience torque and speed, or the thrill of gassing up. Let's also not discuss how most sailors worry more about the excess gas left over in the fall cause they just don't end up using much of the gas they filled up with in May.

My important issues
1) amount of energy/power needed in an emergency for short while
2) amount of energy/power needed to maintain a leisurely speed(2-3 knots)
3) how long can my batteries move me at my leisurely speed
4) can I renew my used/spent energy on a daily basis
5) can I spend most of my time on the water actually sailing . . . with the sails

I think the electric option fits the need of the first 4 and the 5th is not dependent on the source of engine power.


----------



## LakeSuperiorGeezer (Oct 8, 2010)

My wife points out that 50 volts and above can be lethal, especially considering the conductivity of seawater. Most installations are above 50 volts so have to be careful around this equipment.


----------



## tommays (Sep 9, 2008)

Around here the water moves pretty fast with 1 knot being on the light side and even when doing "REAL" sailing failure to plan around it will ensure not getting there


----------



## Mark F (Mar 7, 2006)

Hi Donna,

You wrote, “It does the electric motor industry a disservice by having folks screaming that it is the right way to go for everyone rather than just putting the facts out there and letting people make an informed decision." 

I'm not sure who you are referring to. Most people that I see commenting about EP - that have made the conversion - are pretty up front about the limitations of battery power. 

I think what it comes down to is being comfortable jumping into unfamiliar territory. When I repowered my first sailboat (Ericson 23) with electric in 2005 I had only been sailing for a few years, so I wasn’t all that familiar with any type of auxiliary. After dealing with a finicky outboard it was easy for me to explore EP. On that boat a strong trolling motor (36 volt 105# thrust) worked great, for my mostly daysailing out of Santa Cruz CA. Now I was accustomed to the EP and it was easy for me to envision my next boat (Ericson 27) with an electric inboard.


----------



## kd3pc (Oct 19, 2006)

SURV69 said:


> My important issues
> 1) amount of energy/power needed in an emergency for short while
> 2) amount of energy/power needed to maintain a leisurely speed(2-3 knots)
> 3) how long can my batteries move me at my leisurely speed
> ...


I like WD's conditions, and will note that I agree totally, maybe even adding a top category for over 16,000 lbs..

For the smaller boats:
1. this is a major consideration. A function of torque/prop/motor and ability to sustain high loads for the duration of the event.
2. More of a battery consideration and clean hull than anything else. Hull design would play into it, as well
3. Exactly, you can only rack so many batteries in a 7,000 lb boat, safely
4. This point is a gotcha, no matter what the load is. I have 220 watts of solar, and a windmill. Solar will keep things topped up, but will not replenish my losses without some engine running. On the bay, wind gen is a non issue, almost can not count on it to be anything but icing on the cake. The wind just isn't there for it to perform.
5. If you do not work, did not bring the kids, do not slip up a creek this MAY be possible, for the rest of us, or those of us who actually do go somewhere and expect to return, it is a show stopper.

No comment on the money, as I am one who believes that with enough time and money anything is possible, although in reading Calder and his +40' I am no longer sure that $$ will work. Just too many variables.

That being said, those who have the drive leg hole (as the previous poster documented) on a small boat, the delta between electric and gas is likely not much and electric may work for you. I would not have a gas inboard, but that is just me.

Those of us with 50-60 hp who need quite a bit of that to move the 18K lbs, are likely out of luck with current technology, money or not.

be careful with DC, as those who are double and quad banking 12volt sources need to be cautious of DC burns and correctly protecting all connections....that voltage and the currents will hurt you, in a much different way than AC

thanks for the thought provoking.


----------



## LakeSuperiorGeezer (Oct 8, 2010)

The rule if thumb is 3 to 4 HP per ton, which should propel a sailboat at 2 knots into a force 5 wind when there is at least two miles from the shore. That's also a lot of power required for some hours of time. A force 5 is 18 to 24 mph with moderate waves of some length, many whitecaps, small amounts of spray. More HP would be better and I think getting that kind of power from electric motor and batteries would be too heavy for a sailboat.


----------



## Donna_F (Nov 7, 2005)

Mark F said:


> Hi Donna,
> 
> You wrote, "It does the electric motor industry a disservice by having folks screaming that it is the right way to go for everyone rather than just putting the facts out there and letting people make an informed decision."
> 
> I'm not sure who you are referring to. Most people that I see commenting about EP - that have made the conversion - are pretty up front about the limitations of battery power.


"Screaming" was a poor choice of words. I was frustrated when I wrote this. I should have said "insisting" and that's what I found during my search for answers on more than one forum because a lot of people belong to more than one and the same questions are asked.


----------



## nickmerc (Nov 2, 2008)

LakeSuperiorGeezer said:


> My wife points out that 50 volts and above can be lethal, especially considering the conductivity of seawater. Most installations are above 50 volts so have to be careful around this equipment.


As the old saying goes "volts thrill, amps kill". Any of the batteries we have in our house and start banks can deliver more than enough amperage to kill us if we are not careful. I have personally had around 20,000 volts go through me from one hand to the other. It was from a lawn mower spark plug and the amperage is negligible. Volts alone are not the enemy.

The big limiting factor with electric is power storage. It is really hard to obtain a similar energy density with batteries, using current technology, that fossil fuels have. The motors are more than capable and the drive systems (both the electrical and mechanical components) are extremely efficient.

You have to figure out how much range at what speed you need for the type of sailing you do and the boat you have. Then you have to decide if there is a battery or hybrid solution that will work for you. There isn't much more to worry about as the motor and drive technology has been around for a long time and is more than up to the task. Even for larger boats.

For me when I was on the Chesapeake I just could not find a reasonable solution for power storage for my type of sailing. Mostly for the reasons already stated about having a schedule and needing to get home. However, I am now on a small inland lake. The longest I will have to motor is 20 miles to go from one end to the other and return. That will be just under 4 hrs at hull speed. Most likely it will only be 10 miles to get back home. Now EP is looking like a great idea for my situation.


----------



## jepomer (Nov 29, 2008)

andrewoliv said:


> I am considering re-powering my boat (Mariner 28). The option of converting to an electric drive (Elco) is very appealing. However, I would like to hear from anyone who has an electric drive on their boat. Pro's and Con's.
> 
> I am concerned about power into a strong headwind or current. How well does solar or wind re-charge the batteries. Length of time is also a factor.
> 
> ...


Getting back to the original poster's questions asking for experiences of those who converted...

1) Can an electric motor power a 7500 lbs boat into a strong headwind or current?

Yes, it will. Remember the Queen Mary, submarines, other large vessels are driven by electric motors. The propeller doesn't "know" what is turning the shaft.

2) How well does solar or wind recharge the batteries?

Solar and wind are variable power sources. If the battery is used just to maneuver in and out of the harbor, very little of the potential battery energy is used AND will be better replenished by solar or wind than bulk charging from a diesel/gas engine's alternator/generator. This would happen within one or two days - very acceptable for most day/weekend sailers.

Bulk charging brings the battery capacity back up to 80% of full charge. A "smart" charger is needed to bring a battery back up to 100% of full charge.

If the batteries are discharged very low, an alternate source or recharging would be needed. Or if you have a long enough period of time between uses, the deeply discharged batteries can be recharged by solar and wind.

3) How long can one "motor"?

Most are sized to run maximum speed for typically 2 hours maximum.

In my setup, it draws 120 amps at full speed (just under 6 knots - hull speed). Decreasing the speed to 4 knots, it draws 20 amps. If motor-sailing, I can go 5 knots and draw 10 amps or less. In very light winds, I set the draw to 10 amps. Motor-sailing creates more apparent wind. 10 amp draw out of a 225 amp battery bank gives me almost a full day of motoring. Since we go out for only 6-8 hours, we rarely have depleted the battery past the 50% level - the goal to make the battery last for 6-8 years.

---

Most of us do have schedules to meet. Each individual needs to factor that into the individual's decision making.

Playing the devil's advocate, I notice that most people are quick to turn on the motor rather than use/develop sailing skills.

I have found that since I now sail with a limited amount of engine energy, I save its use until I really need it. I also have become more adept at sailing, aware of currents, tides, and winds.

Remember, until only a century ago, only wind and muscles powered boats - even on the Chesapeake... Just a thought!

John


----------



## SURV69 (Feb 2, 2008)

*Years ago*

I read an article(don't ask me where), that stated that new boats built after the introduction of power plants(steam), included sails cause of a mistrust of these unproven(to the masses), "engines".


----------

