Charging the batteries by running the diesel... - 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 > Diesel
 Not a Member? 

Diesel This is a new forum dedicated to diesel engines and their applicable accessories.


Reply
 
LinkBack Thread Tools
  #1  
Old 10-25-2010
SoulVoyage's Avatar
seeker of wonder
 
Join Date: May 2010
Location: Where the oceans have no address.
Posts: 84
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 5
SoulVoyage is on a distinguished road
Charging the batteries by running the diesel...

I've got a Westerbeke 30 diesel engine (a 4 cylinder 25 hp engine based on the old 2.2 Leyman London taxi engine). Normally, while sailing offshore, the batteries get topped up just fine as I use my engine for motor-sailing at least a couple hours a day to charge batteries while in gear.

But at anchor during weeks of cloudy days, I need to run the engine to charge my banks of deep cycle batteries. I am wondering if the belts for the alternator and saltwater pump create enough of a "load" on the engine while running in neutral? I've heard, as most others have heard, that it is not good to run the engine for long periods in neutral, but I wonder why not...since 18 wheel tractor-trailors run their engines in neutral ALL night long while pulled over. There's no load on their engines, either.

How bad is it to run the engine in neutral? What specific damage does it do? It seems as long as your bottom end bolts are nice and tight, I can't perceive any obvious areas of wear due to lack of opposing force on the crank.

The only decent way I can think of putting load on the system without burning up the propshaft, would be to have some sort of adjustable shaft-brake on the outside portion of the shaft before the propellor, where it can be cooled by seawater...and you'd have to dive down and remove the prop every time!!!!
Or tie-up between two moorings or pilings and run the engine in drive.

Any thoughts on this conundrum?
__________________
"...and a star to steer her by."

Last edited by SoulVoyage; 10-25-2010 at 04:07 AM.
Reply With Quote Share with Facebook
  #2  
Old 10-25-2010
Junior Member
 
Join Date: Apr 2009
Posts: 8
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
prh77 is on a distinguished road
As I understand it, it is a question of glazing the cylinder walls as a result of low load, and then oil use, low compression etc. Everything I have ever read says run these engines hard, 80 % max rated rpm, or suffer the consequences.
Reply With Quote Share with Facebook
  #3  
Old 10-25-2010
Gene T's Avatar
Senior Member
 
Join Date: May 2006
Location: Left Coast USA
Posts: 666
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
Gene T is on a distinguished road
I have looked into this a bit more for motoring at less than 80% for long periods at a time. It seems the damage of running at low rpm's can be reversed by running at full load for something like 10 min. So I would think idling the engine does no real damage if you end up motoring often enough to load it up properly.

Gene
__________________

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

Currently in Long Beach, CA
Reply With Quote Share with Facebook
  #4  
Old 10-25-2010
Senior Member
 
Join Date: Jul 2007
Location: Truckee, CA
Posts: 6,919
Thanks: 2
Thanked 100 Times in 98 Posts
Rep Power: 8
dabnis is on a distinguished road
Soul,
I had a commercial salmon troller with a Detroit Diesel, aka "Jimmie", used to troll for hours on end with no problems. Lots of theories on this issue but I think as long as the engine is run hard after trolling it should be OK. lots of commercial boats with 2 and 4 stroke diesels out there doing the same thing for many years.
Dabnis
Reply With Quote Share with Facebook
  #5  
Old 10-25-2010
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,011
Thanks: 0
Thanked 64 Times in 55 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
While charging at the dock put it in gear. Everybody I know does.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #6  
Old 10-30-2010
Junior Member
 
Join Date: Oct 2010
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
SunGypsy is on a distinguished road
Interesting...thanks Soulvoyage for the question. To add another question to this...

I have the ability to increase my RPM's without putting the engine into gear. Will this have the same effect as having it in gear or is there still not enough load on the engine to prevent this glazing on the cylinder walls?

SG
Reply With Quote Share with Facebook
  #7  
Old 10-30-2010
Faster's Avatar
Just another Moderator
 
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 14,604
Thanks: 67
Thanked 178 Times in 174 Posts
Rep Power: 10
Faster has a spectacular aura about Faster has a spectacular aura about Faster has a spectacular aura about
According to the theories, it's precisely that situation that can lead to 'glazing'.. ie high rpm without serious work load. Charging at low rpms is counterproductive since the alternator output is generally speed related.

Running in gear against the dock lines is definitely a decent load.
__________________
Ron

1984 Fast/Nicholson 345 "FastForward"

".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
Reply With Quote Share with Facebook
  #8  
Old 10-30-2010
Junior Member
 
Join Date: Oct 2010
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
SunGypsy is on a distinguished road
Thanks,

That is what I thought....So what you are saying it is best to pull the anchor and go for a cruise to recharge the battery then to sit.

Cheers,
SG
Reply With Quote Share with Facebook
  #9  
Old 10-30-2010
hellosailor's Avatar
Plausible Deniability
 
Join Date: Apr 2006
Posts: 10,444
Thanks: 1
Thanked 76 Times in 74 Posts
Rep Power: 10
hellosailor has a spectacular aura about hellosailor has a spectacular aura about
Glazing on the cylinder walls, and building up coke (unburned carbon residue) in the exhaust elbow.

Diesels don't like to be run without load, but some modern diesels are apparently built differently to tolerate this. Bear in mind that when a trucker runs his engine all night, that is NOT BY CHOICE. He needs the cabin heater or air conditioner, he needs to know the truck will start up in the morning. That outweighs any other consideration.

Kinda like using your main engine instead of a Honda genset to charge the house bank. :-)
Reply With Quote Share with Facebook
  #10  
Old 10-30-2010
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,011
Thanks: 0
Thanked 64 Times in 55 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
I think the problem on a boat is that the engine may never get much of a workout. Charging the batteries in neutral and running for a very short time to get out of the harbor aren't much different sometimes. The trucker may idle all night but he will run under a good load all the next day. If the sailboat gets a good run that might make a difference but most don't often. And as Faster posted idle will not charge much, you need higher rpm to accomplish anything.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
Reply


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
Running diesel to Charge Batteries LarryandSusanMacDonald Gear & Maintenance 29 09-28-2009 03:28 PM
Batteries not charging Crunchtime Gear & Maintenance 5 09-06-2008 03:40 PM
Charging 8d and 4d wet batteries Brezzin Gear & Maintenance 5 12-27-2006 01:22 PM
Charging Batteries Sue & Larry Gear and Maintenance Articles 0 09-25-2002 08:00 PM
Batteries & Charging capedory30 General Discussion (sailing related) 2 04-27-2001 04:05 PM


All times are GMT -4. The time now is 04:11 PM.

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.