Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 26-09-2011, 10:11   #1
Registered User

Join Date: Sep 2011
Location: Victoria, B.C. Canada
Boat: Islander 32 32'
Posts: 1
Electric Drive

I'm new to this forum, and new to electric drive. Installed an SolidNav Explorer with a double bank of Odessey 1800 and smart chargers last year. Our old Benz diesel had given out. As we do mostly day sailing, are moored in a marina with shore power, this seemed an ideal set up.

Once set up, we had some questions for our supplier in Seattle, but both he and SolidNav seem to have vanished and we feel marooned.

The info that had been prvided was for a 27' Ericson with a claimed 50 kn mi per charge. Accounting for our heavier boat we had hoped for about a 35 kn mi. range per charge. We are getting 1/4 of that at the very reasonable low speed of 3 kn (20 A or 2kW draw). At 30 A we do 4 kn for 10 minutes and then the whole system "throttles" down to a stall. Reverse will work instantly, forward works again after a few minutes.

Without teck support, marine mechanics trained for fossile fuel propulsion, know little more than we do. Any electrical engineers among us sailors?

Any help is appreciated.


TycheVictoria is offline   Reply With Quote
Old 26-09-2011, 10:13   #2
Moderator Emeritus
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 29,334
Images: 240
Re: Electric Drive

Greetings and welcome aboard the CF, Alfred.

Sorry to learn of your difficulties.

FWIW: See our earlier discussion ➥ SolidNav Explorer

Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"

GordMay is offline   Reply With Quote
Old 26-09-2011, 11:51   #3
Registered User
James S's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: Yemen & Lebanon... the sailboat is in Lebenon, the dhow is in Yemen
Boat: 1978 CT48 & 65ft Cargo Dhow
Posts: 5,789
Images: 139
Re: Electric Drive

Welcome to the forum Alfred...
I hope you can find some technical assistance here.
S/V Arctic Lady
I love my boat, I can't afford not to!
James S is offline   Reply With Quote
Old 26-09-2011, 14:34   #4
Nearly an old salt
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Sounds like a controller fault. Or merely your batteries are poor. At 218 ah you don't have a lot of capacity.

Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! -
goboatingnow is offline   Reply With Quote
Old 26-09-2011, 15:33   #5
Eternal Member
Chief Engineer's Avatar

Join Date: Aug 2006
Location: North of Baltimore
Boat: Ericson 27 & 18' Herrmann Catboat
Posts: 3,798
Re: Electric Drive

They aren't a subsidiary of Solyndra...are they?

Sounds like you need mo' batteries
Chief Engineer is offline   Reply With Quote
Old 27-09-2011, 07:10   #6
Registered User

Join Date: Sep 2010
Posts: 793
Re: Electric Drive

I might be able to help, but need some clarification.

You say you have a double bank of Odyssey 1800 batteries. They are rated at 214Ah @12V. How is your double bank wired? In parallel for 428Ah @12V, or in series for 214Ah @24V?

You say at cruise of 3kts you draw 20A or 2kw. For 20A to be 2kw, the voltage would have to be 100V, and it seems that your battery bank is either 12V or 24V, so there is some discrepancy somewhere. What instrument is reporting the 20A and 2kw power draw?

twistedtree is offline   Reply With Quote
Old 27-09-2011, 07:42   #7
Registered User

Join Date: Sep 2010
Posts: 793
Re: Electric Drive

Here's some real quick engineering on your drive system. Hopefully it will shed some light on the problems you are having.

I'll assume you are drawing 2kw when motoring at 3kts. 2kw is equivalent to 2.6hp, and it's believable (just barely) that 2kw could propel your boat at 3kts. As a comparison point, a typical electric bow thruster will draw 200A and lightly push a bow around, so it's believable that the same power could move you forward at 3 kts.

I'll also assume your battery bank is paralleled for 428ah @12V. That would result in a 160-200A battery draw depending on what the actual operating voltage is. I'm guessing your reported 20A draw is a typo and that it's actually 200A.

At 200A draw, you batteries will run for about 60 minutes (actually less) before they are 50% depleted, and 50% depletion is typically what one would design for for reasonable battery life. 60 minutes at 3kts is a traveled distance of 3nm, not 35.

If the draw is only 160A, you would last about 80 minutes for a traveled distance of about 4nm.

To travel 35nm, you would need approximately 10 times the battery capacity that you currently have.

I must be off somewhere in my assumptions because you are actually getting more distance. I'm be happy to rerun the numbers once you setup is clearer.

twistedtree is offline   Reply With Quote


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Autopilot Drive Stopped Message ? stevensuf Marine Electronics 6 25-09-2011 04:52
No Drive and Sounds Like a Bag of Bolts destroyer28a Engines and Propulsion Systems 5 08-09-2011 05:35
Single-Molecule Electric Motor GordMay Electrical: Batteries, Generators & Solar 3 05-09-2011 09:08
Want To Buy: Sonic Sail Drive Tiller Arm jphillips48 Classifieds Archive 0 22-08-2011 08:01
Perkins 4.108 Raw Water Pump Drive Tab OldRover Engines and Propulsion Systems 0 09-08-2011 11:23

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 17:18.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.