Idea for recovering Energy from Idling engine - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 11-07-2010, 10:55 PM   #1
eee
Registered Member
 
eee's Avatar
 
Join Date: Jan 2010
Posts: 19
Country: United States
Question Idea for recovering Energy from Idling engine

Hi everybody, I am wondering if if would be possible to fool the computer so that it has a strong bias on kicking on the alternator while at idle.

If I know where the voltage reading that controls the alternator is, then I could add and subract a bias voltage depending on whether the engine is idling or not idling.

Suppose normally the voltage reading of V is taken

V= Vbatt

If this were to be changed to

V= Vbatt - Vbias where Vbias -0.5V for engine at idle and +0.5 V for engine not at idle .....

then there alternator should likelier kick on at idle.

Any idea how hard it would be to do this?? Not sure if it makes a difference, but my car is OBD1.

Combined with an HHO system, that can turn battery energy into mechanical energy, I think this might gain significant mpg's
__________________

eee is offline   Reply With Quote
Old 11-08-2010, 07:32 AM   #2
Site Team / Moderator
 
Jay2TheRescue's Avatar
 
Join Date: Sep 2008
Location: Northern Virginia
Posts: 4,657
Country: United States
Location: Northern Virginia
Re: Idea for recovering Energy from Idling engine

Having the alternator increase output when its not required, will result in overcharging your battery and decreased life. Also, the alternator is not capable of full output at idle, so if you were to significantly increase the load at idle you will deplete the battery.
__________________

__________________






Jay2TheRescue is offline   Reply With Quote
Old 11-08-2010, 08:02 AM   #3
Registered Member
 
Join Date: Jun 2008
Posts: 256
Country: United States
Re: Idea for recovering Energy from Idling engine

Yeah, yours being an older vehicle (you said OBD1) I am not sure but in newer vehicles the charging output is controlled by the PCM.
__________________
Dave
GasSavers_GasUser is offline   Reply With Quote
Old 11-08-2010, 09:12 AM   #4
Registered Member
 
theholycow's Avatar
 
Join Date: Apr 2008
Posts: 6,624
Country: United States
Send a message via ICQ to theholycow Send a message via AIM to theholycow Send a message via MSN to theholycow Send a message via Yahoo to theholycow
Re: Idea for recovering Energy from Idling engine

The way I read it, eee understands how the computer controls the alternator and wants to try changing that.

It shouldn't be too hard to monkey around with, but I don't think that trying to kick it on during idle will help anything. When idling, it's not using any more fuel than is necessary to idle; adding drag will just increase fuel consumption. At best it is a zero sum game.

Barking up a similar tree, here's an idea that might work: Get a higher-output alternator and run it full-strength during DFCO.
__________________
This sig may return, some day.
theholycow is offline   Reply With Quote
Old 11-08-2010, 12:21 PM   #5
Registered Member
 
theclencher's Avatar
 
Join Date: Aug 2006
Posts: 542
Country: United States
Re: Idea for recovering Energy from Idling engine

But the HHO is certainly a winner!
__________________
Tempo/Topaz:
Old EPA 23/33/27
New EPA 21/30/24

F150:
New EPA12/14/17

theclencher is offline   Reply With Quote
Old 11-08-2010, 12:44 PM   #6
eee
Registered Member
 
eee's Avatar
 
Join Date: Jan 2010
Posts: 19
Country: United States
Re: Idea for recovering Energy from Idling engine

Quote:
Originally Posted by theholycow View Post
It shouldn't be too hard to monkey around with, but I don't think that trying to kick it on during idle will help anything. When idling, it's not using any more fuel than is necessary to idle; adding drag will just increase fuel consumption. At best it is a zero sum game.
Well, as I understand it, at idle the typical engine (anything aside from diesel and direct injection) is running at minimal efficiency while being choked off of air; the purpose is only to keep the engine spinning, and, for the given (engine displacement) * (idle rpm) * (air density), throw in enough fuel to avoid a lean burn condition. That is why most gas engines on the road use ridiculous amounts of fuel, on the order of typically 1/3 gallon per hour (more like over 1/2 gph for V6's and higher) to idle. You're running essentially a vacuum pump.

I usually turn off the engine when I expect to be sitting over a minute or so. But it gets tiresome, and some say, wearing on the starter motor. It would be nice to have an automated system for all these shorter traffic light idles.

My though is that it isn't a zero sum game. I'll increase the efficiency of idle by letting a tiny bit more air (raising the manifold pressure) into the cylinders, and using a tiny bit more fuel to charge the battery. What tiny bit I loose in fuel at idle I expect to more than offset during driving, as the alternator will kick in less frequently while driving.

I'm not so concerned about battery life and willing to an old sacrifice battery for this experiment. The bias voltage can always be adjusted to smaller voltage if that becomes a concern.

Anyways, I have no idea yet where the circuit is that controls the alternator.

Thanks all, for any help and input so far .
eee is offline   Reply With Quote
Old 11-08-2010, 10:28 PM   #7
Registered Member
 
theclencher's Avatar
 
Join Date: Aug 2006
Posts: 542
Country: United States
Re: Idea for recovering Energy from Idling engine

I know for a fact BMW and Honda have developed "smart alternator controllers" that relieve the alt at accel and cruise and work it harder on decel and idle. Claimed fe benefit is a couple percent.
__________________
Tempo/Topaz:
Old EPA 23/33/27
New EPA 21/30/24

F150:
New EPA12/14/17

theclencher is offline   Reply With Quote
Old 11-13-2010, 08:50 AM   #8
Registered Member
 
kamesama980's Avatar
 
Join Date: Nov 2007
Posts: 742
Country: United States
Location: Columbus, IN, USA
Send a message via AIM to kamesama980 Send a message via Yahoo to kamesama980
Re: Idea for recovering Energy from Idling engine

I think you'd have a much higher benefit reducing alternator load during acceleration than increasing it at idle. idle also is going to have the lowest BSFC so doing your charging there is going to use more gas per watt/hr into the battery than while driving. Right idea though. makes me wonder if I can rig something up with my megasquirt...
__________________
-Russell
1991 Toyota Pickup 22R-E 2.4 I4/5 speed
1990 Toyota Cressida 7M-GE 3.0 I6/5-speed manual
mechanic, carpenter, stagehand, rigger, and know-it-all smartass
"You don't get to judge me for how I fix what you break"
kamesama980 is offline   Reply With Quote
Old 11-13-2010, 02:23 PM   #9
eee
Registered Member
 
eee's Avatar
 
Join Date: Jan 2010
Posts: 19
Country: United States
Re: Idea for recovering Energy from Idling engine

Quote:
Originally Posted by kamesama980 View Post
I think you'd have a much higher benefit reducing alternator load during acceleration than increasing it at idle. idle also is going to have the lowest BSFC so doing your charging there is going to use more gas per watt/hr into the battery than while driving. Right idea though. makes me wonder if I can rig something up with my megasquirt...
It has the lowest BSFC because there is no load and the throttle is choking off the air as there is no load. As soon as the load of the alternator is applied the throttle will open up. If you look at the chart and extrapolate to an idle rpm of ~1000, then you'll see the consumption is going to be around 230 versus the theoretical optimum of 206 (for whatever typical engine was used in producing the chart). Anyways, I'd consider that pretty much near optimum. Even if the alternator load were too light, and it was chugging up 300, that's still close enough to the peak that it'd be worth it imo. Point is, the throttle position has much more to do with BSFC than the rpm.
eee is offline   Reply With Quote
Old 11-14-2010, 01:39 AM   #10
eee
Registered Member
 
eee's Avatar
 
Join Date: Jan 2010
Posts: 19
Country: United States
Re: Idea for recovering Energy from Idling engine

Oops that may have made little sense, as I totally forgot to provide the link;

See first figure in:
http://en.wikipedia.org/wiki/Brake_s...el_consumption
__________________

eee is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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
Fuelly Android App - eehokie Fuelly Web Support and Community News 2 07-14-2010 09:59 PM
Sort on Hybrid Vehicles mikeg Fuelly Web Support and Community News 2 01-12-2010 06:21 PM
Incorrect Milage Calcuatlion PatM Fuelly Web Support and Community News 4 07-17-2009 08:21 PM
Lighter weight motor oil for improved FE? Greybrick General Fuel Topics 5 06-18-2008 01:29 PM
Affordable scanguage? lawnguybri General Fuel Topics 6 01-30-2008 07:22 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 01:13 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.