Go Back   EcoModder Forum > EcoModding > General Efficiency Discussion
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 03-29-2013, 11:43 AM   #1 (permalink)
EcoModding Lurker
 
Join Date: Mar 2013
Location: Switzerland
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts
Alternator with magnetic coupling?

Hello people


Why not a alternator with magnetic coupling (Clutch)?
When the battery ist full, the shut down the alternator?

5-7% better efficiency?

cu

PowerPiston


Sorry my english is not good. I come from Switzerland.

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 03-29-2013, 11:54 AM   #2 (permalink)
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 11,203

CM400E - '81 Honda CM400E
90 day: 51.49 mpg (US)

Daox's Grey Prius - '04 Toyota Prius
Team Toyota
90 day: 49.53 mpg (US)

Daox's Insight - '00 Honda Insight
90 day: 64.33 mpg (US)

Swarthy - '14 Mitsubishi Mirage DE
Mitsubishi
90 day: 56.69 mpg (US)

Daox's Volt - '13 Chevrolet Volt
Thanks: 2,501
Thanked 2,585 Times in 1,553 Posts
Welcome to the site. Alternators do not put a constant load on the engine. If the battery voltage is low they put out a lot of current. If the battery voltage is high they don't put out a lot of current. There really isn't a reason to physically decouple the alternator from the engine. Even the guys who do 'alternator deletes' usually just install a switch to stop the alternator from generating any power versus physically changing things.
__________________
Current project: A better alternator delete
  Reply With Quote
Old 03-29-2013, 11:55 AM   #3 (permalink)
Master EcoModder
 
razor02097's Avatar
 
Join Date: Jan 2013
Location: ohio
Posts: 306

Tetanus - '95 Geo Tracker 4WD Base
90 day: 29.43 mpg (US)

300 - '82 Suzuki GS300 L
Last 3: 60.78 mpg (US)

Jeep - '98 Jeep XJ Cherokee Limited
90 day: 12.82 mpg (US)
Thanks: 28
Thanked 50 Times in 37 Posts
There have been ideas before about putting an air conditioning compressor on the alternator. From what I have heard the size of the pulley may cause issue with charging the battery because it is too big.
__________________



Project Avalon: E bike build
  Reply With Quote
Old 03-29-2013, 12:22 PM   #4 (permalink)
EcoModding Lurker
 
Join Date: Mar 2013
Location: Switzerland
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts
the friction of the alternators is not to be underestimated
  Reply With Quote
Old 03-29-2013, 12:31 PM   #5 (permalink)
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 11,203

CM400E - '81 Honda CM400E
90 day: 51.49 mpg (US)

Daox's Grey Prius - '04 Toyota Prius
Team Toyota
90 day: 49.53 mpg (US)

Daox's Insight - '00 Honda Insight
90 day: 64.33 mpg (US)

Swarthy - '14 Mitsubishi Mirage DE
Mitsubishi
90 day: 56.69 mpg (US)

Daox's Volt - '13 Chevrolet Volt
Thanks: 2,501
Thanked 2,585 Times in 1,553 Posts
Have you spun an alternator by hand? Its quite easy to do. The friction is nothing compared to everything else going on in a car.
__________________
Current project: A better alternator delete
  Reply With Quote
Old 03-29-2013, 12:37 PM   #6 (permalink)
Master EcoModder
 
Join Date: Jun 2008
Location: Earth
Posts: 5,209
Thanks: 225
Thanked 811 Times in 594 Posts
The main energy loss would be in belt friction, so you would need to have the decoupling on the crankshaft pulley. The problem is that the same belt often drives fans, power steering pump, etc.
  Reply With Quote
The Following User Says Thank You to jamesqf For This Useful Post:
Ryland (03-29-2013)
Old 03-29-2013, 12:39 PM   #7 (permalink)
EcoModding Lurker
 
Join Date: Mar 2013
Location: Switzerland
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Daox View Post
Have you spun an alternator by hand?
No i haven't.
  Reply With Quote
Old 03-29-2013, 01:02 PM   #8 (permalink)
Master EcoModder
 
Join Date: Jul 2008
Location: NY state
Posts: 501

XJ Cherokee - '00 Jeep Cherokee Sport
90 day: 12.96 mpg (US)

FoFO - '11 Ford Focus SE
90 day: 36.78 mpg (US)
Thanks: 1
Thanked 51 Times in 38 Posts
You can spin an alternator with no load pretty easy. An alternator with load isn't so easy.
  Reply With Quote
Old 03-29-2013, 01:24 PM   #9 (permalink)
...beats walking...
 
Join Date: Jul 2009
Location: .
Posts: 6,190
Thanks: 179
Thanked 1,525 Times in 1,126 Posts
...simply attach an AIRCONDITIONING CLUTCH to the alternator, that way YOU can control it's mechanical coupling & engagement whenever you want...or, have it electronically controlled by something.
  Reply With Quote
Old 03-29-2013, 02:45 PM   #10 (permalink)
Master EcoModder
 
mechman600's Avatar
 
Join Date: Jul 2008
Location: Langley, BC
Posts: 1,228

Fusion - '16 Ford Fusion Hybrid SE
Thanks: 190
Thanked 275 Times in 168 Posts
Belt friction isn't much either. Obviously more than no belt, but that's hard to do. The latest Toyota hybrids are completely beltless, so obviously there is some gain, but in the grand scheme of things? Like Daox said, it's not much.

The best would be like what Mazda is doing soon. The alternator charges when decelerating and turns off when accelerating, and charges a large capacitor to keep the charging system happy all the time. Maybe someone needs to invent a DIY version.

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com