Electric Conversion - Page 3 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 


Like Tree2Likes
Reply
 
LinkBack Thread Tools
  #21  
Old 11-08-2011
Banned
 
Join Date: Apr 2011
Location: Southern California
Posts: 649
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
WDS123 is on a distinguished road
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.
kd3pc likes this.
Reply With Quote Quick reply to this message Share with Facebook
  #22  
Old 11-08-2011
Junior Member
 
Join Date: Feb 2008
Location: Warren Ohio
Posts: 24
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
SURV69 is on a distinguished road
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.
Reply With Quote Quick reply to this message Share with Facebook
  #23  
Old 11-08-2011
LakeSuperiorGeezer's Avatar
Senior Member
 
Join Date: Oct 2010
Posts: 551
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5
LakeSuperiorGeezer is on a distinguished road
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.
Reply With Quote Quick reply to this message Share with Facebook
  #24  
Old 11-08-2011
tommays's Avatar
Senior Member
 
Join Date: Sep 2008
Posts: 4,282
Thanks: 1
Thanked 29 Times in 29 Posts
Rep Power: 7
tommays will become famous soon enough
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
__________________
1970 Cal 29 Sea Fever

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

1981 J24 Tangent 2930
Tommays
Northport NY


If a dirty bottom slows you down what do you think it does to your boat
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
  #25  
Old 11-08-2011
Member
 
Join Date: Mar 2006
Location: Felton CA
Posts: 75
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
Mark F is on a distinguished road
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.
Reply With Quote Quick reply to this message Share with Facebook
  #26  
Old 11-08-2011
kd3pc's Avatar
Senior Member
 
Join Date: Oct 2006
Location: Callao, VA
Posts: 1,355
Thanks: 0
Thanked 9 Times in 9 Posts
Rep Power: 9
kd3pc is on a distinguished road
Quote:
Originally Posted by SURV69 View Post


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.
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.
Reply With Quote Quick reply to this message Share with Facebook
  #27  
Old 11-08-2011
LakeSuperiorGeezer's Avatar
Senior Member
 
Join Date: Oct 2010
Posts: 551
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5
LakeSuperiorGeezer is on a distinguished road
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.

Last edited by LakeSuperiorGeezer; 11-08-2011 at 03:42 PM.
Reply With Quote Quick reply to this message Share with Facebook
  #28  
Old 11-08-2011
DRFerron's Avatar
A mod and her dragon
 
Join Date: Nov 2005
Location: SE Pennsylvania
Posts: 4,170
Thanks: 70
Thanked 160 Times in 144 Posts
Rep Power: 10
DRFerron is on a distinguished road
Quote:
Originally Posted by Mark F View Post
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.
__________________
Donna


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Catalina 30 TRFK

Contributing Editor
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
magazine

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Rock Hall Cruising Station

All things that are, are equally removed from being nothing. John Donne
Reply With Quote Quick reply to this message Share with Facebook
  #29  
Old 11-08-2011
nickmerc's Avatar
Senior Member
 
Join Date: Nov 2008
Location: O'Fallon, MO
Posts: 563
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 7
nickmerc is on a distinguished road
Quote:
Originally Posted by LakeSuperiorGeezer View Post
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.
Reply With Quote Quick reply to this message Share with Facebook
  #30  
Old 11-09-2011
Junior Member
 
Join Date: Nov 2008
Location: Lyndeborough NH
Posts: 17
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jepomer is on a distinguished road
Quote:
Originally Posted by andrewoliv View Post
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
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
Reply With Quote Quick reply to this message Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Jabsco Electric Conversion LakePirate Gear & Maintenance 13 03-01-2011 04:18 PM
AH conversion MLM2 Electrical Systems 5 04-11-2009 03:14 PM
what is the conversion for blt2ski General Discussion (sailing related) 8 02-06-2008 10:52 AM
Head - electric conversion or new electric head snw Gear & Maintenance 5 04-29-2007 08:07 AM
Cal 27 Pop Top Conversion DonaldAdams General Discussion (sailing related) 2 07-11-2006 12:24 AM


All times are GMT -4. The time now is 09:26 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.