Repowering with an electric engine? - Page 9 - 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 > Engines > Electric/Hybrid
 Not a Member? 


Like Tree46Likes
Reply
 
LinkBack Thread Tools
  #81  
Old 05-02-2014
Senior Member
 
Join Date: Feb 2012
Location: New Orleans Louisiana
Posts: 1,926
Thanks: 6
Thanked 43 Times in 41 Posts
Rep Power: 3
Stumble is on a distinguished road
Re: Repowering with an electric engine?

I am one of the most consistent critics of electric power for exactly these reasons. Despite that I actually had a boat with an electric motor. The reality is that the energy density of batteries just isn't sufficient for anything but in and out of the harbor. If that's all you need then go for it, but it isn't a replacement for a diesel.


Brian,

There are some very good numbers from the manufacturers of towed generators. Basically until the boat hits 4kn there isn't much power generation going on, after that there is a pretty steep increase in power generation.
christian.hess likes this.
__________________
Greg Rubin
Attorney
Reply With Quote Share with Facebook
  #82  
Old 05-02-2014
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,109
Thanks: 0
Thanked 71 Times in 62 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
Re: Repowering with an electric engine?

Quote:
Originally Posted by Stumble View Post
I am one of the most consistent critics of electric power for exactly these reasons. Despite that I actually had a boat with an electric motor. The reality is that the energy density of batteries just isn't sufficient for anything but in and out of the harbor. If that's all you need then go for it, but it isn't a replacement for a diesel.


Brian,

There are some very good numbers from the manufacturers of towed generators. Basically until the boat hits 4kn there isn't much power generation going on, after that there is a pretty steep increase in power generation.
I am aware of the numbers from the manufacturers of towed generators. I sell the Ampair/Aquair line and they are effective producing about one amp of current per knot of boat speed. So at 5 knots you get about 5 amps with a hit of maybe 1/4 knot of boat speed unless the boat is larger.

What I want to know is what do electric drives return in regen mode into a 48 volt bank on say a 30' or 35' monohull? In the real world, not a manufacturer's spec sheet number.

I have an electric outboard on my dinghy and a solar panel for charging it whether it is at the dock or in use. I just fail to see how it can translate to a cruising (not daysailed) boat.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #83  
Old 05-02-2014
christian.hess's Avatar
Senior Member
 
Join Date: Sep 2013
Location: el salvador
Posts: 3,825
Thanks: 100
Thanked 152 Times in 148 Posts
Rep Power: 1
christian.hess is on a distinguished road
Re: Repowering with an electric engine?

Quote:
Originally Posted by mitiempo View Post
Agreed. I did say that electric can make sense for one who daysails or only is away from shorepower for a few days.

But for those travelling farther afield it doesn't work.

And I have yet to see actual regen stats anywhere.
hmmm I have seen quite a few builds and repowers were they posted regen stats...on those displays that came with the kits

my thought was that regen actually make sense for voyagers and ocean goers over long periods of time versus say a coastal cruiser that doesnt have access to shore power

for example somoene doing a non stop circumnav or a san fran to hawaii trip where you only use the engine a few times to me electric with regen makes more sense here, since basically you will be regenerating the whole way...

(the regen stats I read up where that most boats started around 4knots putting back into the system, and that if they used a little throttle it would help reduce the motors drag and the prop would spin up easier too...)

anything over 5-6 knots and the amps put back in increased substantially...mostly dependant on prop type.

its like wind power...youll get more wind in steady trades than you will at the marina in bewteen all the boats and structures etc...

my thought was that regen, on long voyages makes more sense, since you dont use the motor untill you get to port or need to anchor etc...

again it comes down to preferences...obviously if you are the kind that motor sails if speeds goes under 5 knots, electric is not for you...

if you have access to shore power and are coastal hopping and marina hopping I dont see where having such a big bank is either necessary or worth comparing to conventional fuel

as when doing so with diesel or gas you never completely use up you tanks either...we didnt for sure when coastal cruising...

the ongoing dilema has always been that in non stop runs electric has maybe 10% the range that conventional boat with inboard tanks has...but if you use it sparingly and have ways of recharging it can and has been done...

those were my thoughts

also I liked the small battery bank conversions for the same reasons, say 4 batteries instead of 8 or 12 or 16...because if depleted it will be quicker to recharge...not only that but he initial expense and cost of chargers etc...goes down exponentially

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

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

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Islander 36 refit still going on...

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #84  
Old 05-02-2014
christian.hess's Avatar
Senior Member
 
Join Date: Sep 2013
Location: el salvador
Posts: 3,825
Thanks: 100
Thanked 152 Times in 148 Posts
Rep Power: 1
christian.hess is on a distinguished road
Re: Repowering with an electric engine?

Quote:
Originally Posted by Stumble View Post
I am one of the most consistent critics of electric power for exactly these reasons. Despite that I actually had a boat with an electric motor. The reality is that the energy density of batteries just isn't sufficient for anything but in and out of the harbor. If that's all you need then go for it, but it isn't a replacement for a diesel.


Brian,

There are some very good numbers from the manufacturers of towed generators. Basically until the boat hits 4kn there isn't much power generation going on, after that there is a pretty steep increase in power generation.
this is what I read up too

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

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

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Islander 36 refit still going on...

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #85  
Old 05-02-2014
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,109
Thanks: 0
Thanked 71 Times in 62 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
Re: Repowering with an electric engine?

Quote:
Originally Posted by christian.hess View Post
hmmm I have seen quite a few builds and repowers were they posted regen stats...on those displays that came with the kits


for example somoene doing a non stop circumnav or a san fran to hawaii trip where you only use the engine a few times to me electric with regen makes more sense here, since basically you will be regenerating the whole way...

(the regen stats I read up where that most boats started around 4knots putting back into the system, and that if they used a little throttle it would help reduce the motors drag and the prop would spin up easier too...)

anything over 5-6 knots and the amps put back in increased substantially...mostly dependent on prop type.

its like wind power...youll get more wind in steady trades than you will at the marina in bewteen all the boats and structures etc...

my thought was that regen, on long voyages makes more sense, since you dont use the motor untill you get to port or need to anchor etc...

if you have access to shore power and are coastal hopping and marina hopping I dont see where having such a big bank is either necessary or worth comparing to conventional fuel

also I liked the small battery bank conversions for the same reasons, say 4 batteries instead of 8 or 12 or 16...because if depleted it will be quicker to recharge...not only that but he initial expense and cost of chargers etc...goes down exponentially

When you use a little throttle you aren't generating power but using it.

Small banks? 4 12 volt 100 AH batteries to create a 40 volt bank is only 100 AH @ 48 volts - probably less than an hours running at slow speed.

Again though reading specs is rather useless. What has anyone actually achieved using regen in the real world? How much is put into the batteries at 4, 5, or 6 knots allowing for inefficiencies that exist when charging? You always have to put more in than you remove from batteries. Who is actually doing this with reasonable results?
christian.hess likes this.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #86  
Old 05-02-2014
christian.hess's Avatar
Senior Member
 
Join Date: Sep 2013
Location: el salvador
Posts: 3,825
Thanks: 100
Thanked 152 Times in 148 Posts
Rep Power: 1
christian.hess is on a distinguished road
Re: Repowering with an electric engine?

Quote:
Originally Posted by mitiempo View Post
When you use a little throttle you aren't generating power but using it.

Small banks? 4 12 volt 100 AH batteries to create a 40 volt bank is only 100 AH @ 48 volts - probably less than an hours running at slow speed.

Again though reading specs is rather useless. What has anyone actually achieved using regen in the real world? How much is put into the batteries at 4, 5, or 6 knots allowing for inefficiencies that exist when charging? You always have to put more in than you remove from batteries. Who is actually doing this with reasonable results?
its what the guys using it and making them recomended...it helps counteract the drag created by the bigger props...its like clutch drag...it helps fight the initial resistance created by the prop and the motor isnt dragging per se like it would off...

electric motors have a lot of initial resistance depending on the windings...so the guys building them said to turn it on ever so slightly and then after you gain speed regen kicks in so no you arent using more than you are putting in if you know what you are doing...

Id recomend searching again..I did and got LOTS of usefeul info from many sources..

the one with the regen speeds was something like 2 or 3 amps at 6 knots or so...so for passages I find that ok...

I did not here on sailnet for example...I even had my electric islander 36 thread...that really didnt go anywhere as people loved to always recomend a 50hp diesel in a 30 footer! which I found hilarious btw...

regarding the small banks you are right the simple calculations I got from heavy duty lead acid simple batteries was around 45min to an hour at 3/4 throttle and around 2-3 at 1/4 throttle or high idle...

for me though that was ok...I didnt need more

in the end though I havent done it down here so I really cant say for sure how it all would of turned out

I did however get very involved in the yahoo electric forum, cloud electric or something like that, even people in other countries with diy builds and the like, etc...

there is A LOT of info out there
__________________
Finally sailed!!!!!!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

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

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Islander 36 refit still going on...

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #87  
Old 05-02-2014
zeehag's Avatar
snake charmer, cat herder
 
Join Date: Nov 2008
Location: refitting a formosa in exotic tropical locations....
Posts: 1,646
Thanks: 4
Thanked 23 Times in 23 Posts
Rep Power: 6
zeehag is on a distinguished road
Re: Repowering with an electric engine?

you can jack your jaws all day here or you can go to one sailor who has done the electric conversion on a long range sailcruiser...lol..and you also do not attend to fact that torqueedo has a solar charger which when you use the torqueedo is able to recharge the battery..what a concept... geez, guys, go to fb, pitt bolinate, he is so proud of his electric drive he will surely tell all about it.
__________________

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

formosa 41 and ericson 35mII
cruising tropical mexico at present, working my way southward



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #88  
Old 05-02-2014
Senior Member
 
Join Date: Feb 2013
Location: South of Albuquerque
Posts: 393
Thanks: 0
Thanked 15 Times in 13 Posts
Rep Power: 2
desert rat is on a distinguished road
Re: Repowering with an electric engine?

As a technician I look at the losses. Electric motors have large losses, as large as the generator, storage is ineficient, with all the losses I'll stick with diesel. In an emergency where you need the auxilary for 2 or 3 days your electric is not going to cut it. Good luck, and fair skies.
__________________
Zen is a matter of recognizing reality.
Reply With Quote Share with Facebook
  #89  
Old 05-02-2014
christian.hess's Avatar
Senior Member
 
Join Date: Sep 2013
Location: el salvador
Posts: 3,825
Thanks: 100
Thanked 152 Times in 148 Posts
Rep Power: 1
christian.hess is on a distinguished road
Re: Repowering with an electric engine?

Quote:
Originally Posted by zeehag View Post
you can jack your jaws all day here or you can go to one sailor who has done the electric conversion on a long range sailcruiser...lol..and you also do not attend to fact that torqueedo has a solar charger which when you use the torqueedo is able to recharge the battery..what a concept... geez, guys, go to fb, pitt bolinate, he is so proud of his electric drive he will surely tell all about it.

hes not the only one...there are quite a few out there

I agree people have and are effectively sailing like this but just saying so isnt what mitiempo for example is wanting to know...

he wants real facts and results...sometimes its hard to get

I know I hit many dead end posts and forums regarding electric
__________________
Finally sailed!!!!!!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

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

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Islander 36 refit still going on...

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #90  
Old 05-02-2014
Senior Member
 
Join Date: Feb 2012
Location: New Orleans Louisiana
Posts: 1,926
Thanks: 6
Thanked 43 Times in 41 Posts
Rep Power: 3
Stumble is on a distinguished road
Re: Repowering with an electric engine?

Zee,

Then look at what Lagoon did. With a huge budget, massive technical support, and major commercial interest they spent years trying to get it right and then replaced (or offered to) all the electric drives they installed.

There are usage profiles that electric drives work for, some where electric is a very clear winner. But that doesn't describe most cruisers, most weekend gunkholers. It is however the ideal option for inshore racers and daysailors.
__________________
Greg Rubin
Attorney
Reply With Quote Share with Facebook
Reply

Tags
electric inboard , recharging , repowering , solar panels


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
which engine for repowering? prussell Diesel 8 02-01-2014 04:19 PM
Replacing Engine Driven Water pump with electric seanreid71 General Discussion (sailing related) 17 10-13-2013 09:39 PM
Replacing IC engine with electric motor WilliamsRDan Electrical Systems 13 10-11-2012 06:27 AM
does it make sense to buy a boat without an engine and convert it to electric? rmeador Gear & Maintenance 32 02-25-2010 02:46 PM
Adding electric compressor to engine-run fridge Bene505 Gear & Maintenance 19 03-08-2009 12:23 PM


All times are GMT -4. The time now is 07:00 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.