High Output Alt and Engine Load - 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 > General Interest Forums > Gear & Maintenance
 Not a Member? 
  #1  
Old 03-28-2009
Barking Dog
 
Join Date: Nov 2005
Location: Boston
Posts: 235
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
KindOfBlue is on a distinguished road
High Output Alt and Engine Load

I have read that it is generally bad practice to use your engine to charge your batteries unless the engine is under load (in gear). Does a high output alternator put enough load on the engine so that it is safe to charge on the mooring/anchor?
__________________
Craig
Reply With Quote Share with Facebook
  #2  
Old 03-28-2009
Melrna's Avatar
Crazy Woman Boat Driver
 
Join Date: Apr 2004
Location: New Bern NC
Posts: 777
Thanks: 15
Thanked 10 Times in 7 Posts
Rep Power: 11
Melrna will become famous soon enough
Send a message via AIM to Melrna Send a message via Yahoo to Melrna
Operating a diesel engine with no load or constant low RPM is bad. I believe what happens is called wetting in the cylinders. As to your question of a high output alternator that depends. How high and what size engine you have? Most small engines under 36 horsepower the biggest alternator one can put on without major modifications is 100amps. Over that amperage, one needs to put on a double pulley system or two alternators opposite of each other. One will lose about 3 Horsepower on the engine for high output alternators. 3 horsepower is not a big load on the engine.
Having said all that, charging the batteries using only the engine can be done. One has to remember that max output on a alternator is not achieved until around 80-90% of engine RPM. So running at that RPM is better for the engine than idle or low RPM. Second, I would recommend run your engine under full load (motorsail) for a time afterward to clear out any wetting process that takes place. If most of your hours on the engine is charging the batteries I would find another way to do that i.e.; generator, solar panels.
__________________
Melissa Renee
Moondance
Catalina 445, Hull #90
Reply With Quote Share with Facebook
  #3  
Old 03-28-2009
Senior Member
 
Join Date: May 2004
Location: Long Is.
Posts: 329
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
gc1111 is on a distinguished road
Diesels are not that delicate! Running one under a light load (like an alternator) is not good for the engine, but not dangerous. Mostly what happens is a buildup of carbon fouling. You can spend a winter in the Bahamas, living on the anchor, using the engine only for charging, and the engine will survive. Lots do that. The next time you spend some time motoring at full power, it will probably clean itself out. But notice the "probably". It is more important to run the diesel at full cruising rpm when you are using it for propulsion.
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
Scheduled trip - part 2 Omatako General Discussion (sailing related) 15 08-20-2007 11:31 AM


All times are GMT -4. The time now is 04:37 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