Regenerative braking? - Page 2 - Fuelly Forums

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

Reply
 
Thread Tools Display Modes
 
Old 11-24-2007, 08:40 AM   #11
Registered Member
 
Join Date: Nov 2007
Posts: 228
Country: United States
I would think a different size pulley for the alternator could reduce alt. rpm's and thus load, thou it would also reduce battery recharge and for this matter just getting a lesser-amp alternator would have a similar effect and the last thing I'm doing is messing with that!

Yes I think a solar panel that can recharge the battery when the car sits might help, if nothing else it's free energy, but whether it will help mpg on a non-hybrid is still doubtful.

A 30amp alternator simply doesn't put much strain on an engine, maybe with ALL accessories running (wipers+fan4+lights) but that's somewhat unusual.
The a/c is far worse, that's where to start with economy, so long the a/c is running there's no need to think along the lines of alternator improvements.

Quote:
Originally Posted by mjo View Post
I'll contribute a few ideas:

- A turbo driven alternator
- Having an alternator being driven by fluid in an automatic transmission. Then you can charge a battery more and brake at the same time by downshifting.
There might be something to it at this angle.
__________________

__________________
A FE gauge should be standard equipment in every vehicle.
8307c4 is offline   Reply With Quote
Old 11-24-2007, 09:19 AM   #12
Registered Member
 
JanGeo's Avatar
 
Join Date: Jan 2006
Posts: 2,442
Country: United States
Send a message via Yahoo to JanGeo
This all leads back to what I and Dan at eCycle thought up and that is to add one of their ISA motors (Integrated Starter Alternator) to your car and use it to start charge and drive your motor thus making it a parallel hybrid and all you need to do is add a higher voltage battery and their motor and controller and some sort of control system to make it all work. Basically you operate your gas motor like usual and add power to it from the electric motor which also recharges the battery very efficiently - more efficiently and quickly than the convential alternator. Plus by operating at a higher voltage and up to 450 amps you charge and regen brake with more energy that an alternator. Now if there was only a way to get the engine to freewheel by holding valves open or maybe closed you could run on pure electric right though the conventional drive train. All you have to do is connect the motor with the right size syncronous pulleys and a belt off the crank pulley.
__________________

JanGeo is offline   Reply With Quote
Old 11-24-2007, 09:52 AM   #13
Registered Member
 
Jim Dunlop's Avatar
 
Join Date: May 2007
Posts: 125
Country: United States
I keep thinking about harnessing the thermal energy by running water through tubes against the brake pads. The intense heat would create steam. There has to be a good way to capture this energy such as a steam turbine alternator.
__________________

Team: Right Lane Rollers
Jim Dunlop is offline   Reply With Quote
Old 12-05-2007, 09:38 AM   #14
Registered Member
 
Join Date: Nov 2007
Posts: 228
Country: United States
Well now that's an interesting angle, to have regen braking do 99% of the battery re-charge, the alternator itself does almost nothing while driving. DO keep in mind the spark plugs need a lot of power, specifically the coil, reduce this and you reduce engine efficiency. And yes, if you reduce the spark's power too much your mpg will suffer, I am 100% sure of this

But you know, you're as well off if you have a clutch-driven fan to replace that with an electrical thermostat-controlled one, they're like 80 bucks each and a short afternoon... Supposedly this shaves 4-5 hp off the engine load, but I will also say that doing this to a 1988 T-bird didn't do anything I could feel or notice, neither in performance nor mpg, mostly a waste of time it was.

Another idea is high performance alloy pulleys (like for racing), they're made of a light weight aluminum and might be slightly larger in diameter to allow rpm reduction. Still, I checked into this and most are for racing only, they're just not practical in road applications because it will over time do more harm than good.
__________________
A FE gauge should be standard equipment in every vehicle.
8307c4 is offline   Reply With Quote
Old 12-10-2007, 01:29 PM   #15
Registered Member
 
Join Date: Nov 2007
Posts: 1,111
Country: United States
Send a message via AIM to dkjones96
I think he means an under drive pulley. A lot of race enthusiasts use them to free up some power by reducing the diameter of the crank pulley so all the accessories run slower and hence take less power from the engine. I personally have never recommended this because of the fact that it does turn everything slower.

As for the alternator being switched. Wouldn't it be better to connect it to run as long as the throttle body is fully closed? Especially for the people here that rarely need to use their brakes. At lights when I drive a manual, I don't hold the brakes if it's flat.

As for harnessing thermal energy. What about getting it from the exhaust? that gets more than hot enough. Especially at the catalytic converter.
__________________
- Kyle
dkjones96 is offline   Reply With Quote
Old 12-20-2007, 06:05 AM   #16
Registered Member
 
Join Date: Oct 2007
Posts: 27
Country: United States
Here is a good overview of different methods of using waste heat to regain power: http://www.heat2power.net/en_benchmark.htm
GasSavers_HAHA is offline   Reply With Quote
Old 12-21-2007, 10:56 AM   #17
Registered Member
 
Join Date: Aug 2007
Posts: 107
Country: United States
What about replacing the rear brakes with motor/generators? If they were both 5 HP you would only really need to store 30 seconds of charge or so. 600 amps is about 10HP do you would need to store about 600/120 5 amp hours. Put a switch when you barely press on the brake pedal it goes to full charging. Put a button on the top of the stick that goes to full power forward. Push the button for a little while on start and then drop it in second. Save a lot on the clutch wear and gas
FritzR is offline   Reply With Quote
Old 12-21-2007, 11:29 AM   #18
Registered Member
 
GasSavers_Ryland's Avatar
 
Join Date: Mar 2006
Posts: 1,325
Country: United States
Send a message via AIM to GasSavers_Ryland
Quote:
Originally Posted by FritzR View Post
What about replacing the rear brakes with motor/generators? If they were both 5 HP you would only really need to store 30 seconds of charge or so. 600 amps is about 10HP do you would need to store about 600/120 5 amp hours. Put a switch when you barely press on the brake pedal it goes to full charging. Put a button on the top of the stick that goes to full power forward. Push the button for a little while on start and then drop it in second. Save a lot on the clutch wear and gas
two motors of that size should be able to lock up your wheels at nearly any speed.
For what you could spend on designing your own system, there at least used to be a system that was avalible that would replace your alternator with a motor/generator, giving you both more power, and regen braking, and it was suposed to be rather simple to install.
GasSavers_Ryland is offline   Reply With Quote
Old 01-16-2008, 04:27 AM   #19
Registered Member
 
s2man's Avatar
 
Join Date: Jun 2007
Posts: 123
Country: United States
I've been thinking along DracoFelis' lines; disabling the alternator during cruising and enabling it during braking. Except instead of just turning the alternator on when braking, I would enable it any time TPS is at 0. This cover the braking situations, and generate some juice while downhill coasting. When I neutral-coast with my automatic, the engine continues to spin at around 1100 rpm. Turning the headlights or heater fan on reduces the rpm by about 30 for each. So I know the alternator is working at those rpms, and I figure I could use some of those 'free' rpm's to run the alt. (I know, they are not free. The energy is coming from my momentum or from gravity at 0 TPS) I would also enable the alternator anytime I was using high-load accessories, such as the headlights or heater, to prevent excessive discharging.

I've got a 100 amp alternator for decent charge rates. And an AGM battery, which should handle the discharging and rapid recharging just fine. I ordered an ammeter and pillar mount this week, so I can monitor the charging system better than with just a volt meter.

Now the question. I see Metro removing his belt, and Brock pulling the fuse, to disable the alternator. Has anyone cut the field wire to their alternator to disable it yet? I may be the guinea pig.
__________________
Roll on,
S2man

s2man is offline   Reply With Quote
Old 01-17-2008, 04:15 PM   #20
Registered Member
 
Join Date: Apr 2007
Posts: 79
Country: United States
As mentioned, BMW has experimented with the idea of using regen braking in place of the alternator. If the charge gets too low, the alternator is then engaged to produce the needed power. ( http://www.autobloggreen.com/2007/03...raking-system/ )

I hate braking. If there's any single enemy of the hypermiler, it is braking. Brakes are designed to remove energy from the system. Now, there are methods you can use to limit how much braking you do, but you can't eliminate all of it.

There are many, many ways to do regen braking and probably even more uses for it. Personally, I want a system that will power my car at about 5mph for intermittently for maybe a total time of 2 minutes (that's 2 minutes of rolling at 5mph). PWM would do wonders for it once it got rolling. Here's why I want this. Whenever I'm in traffic at rush hour, I'm constantly moving a little forward and then coming to a stop for about 30sec. It puts quite a strain on the battery and starter to keep shutting the car off and turning it back on. It's also a pain in the *** and the angry souls behind me probably get all pissy if I'm my front bumper isn't almost touching the rear bumper of the car in front of me.

It seems as though the most efficient regen braking is electrical in form. My car is front wheel drive, so I'm thinking one of the rear wheels would be a prime candidate since there's a limited number of stuff in the way back there. Any thoughts on how to accomplish this or what sized motor would be needed? It'd be great to just engage a big 'ol spring between the rear wheels when slowing down and then releasing its energy as needed, but I don't think that'd work all that well.

Matt
__________________

__________________
I see no reason why fuel economy and power cannot coexist.
DrivenByNothing is offline   Reply With Quote
Reply

« Opinions | CRX mods »
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
more fuel up options slineaudi Fuelly Web Support and Community News 4 07-02-2010 03:11 AM
New to the forum..92 Protege DX jj94auto General Fuel Topics 3 04-24-2007 11:31 AM
Solar Concept Scorn Electric and Solar powered 9 01-13-2007 06:14 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 11:22 AM.


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