Regenerative Charging

[FritzR]

Edit: Here's what I came up with for this mod finally thanks for the input everyone.

I'm going to run the alternator field off the brake light switch on the brake pedal. I'll replace the brake lights with low wattage LEDs to free up a few amps for the alternator field. I am going to run the voltage from the brake pedal switch through a diode so it can only flow from the switch to the alternator, not back. I'm going to hook this in through another diode to the running light relay or whatever. So if you run with the headlights on the alternator behaves as stock. If the headlights are off it only charges when the brake lights are activated. I'm using the running lights because they are on all the time when the lights are on unlike the high and low beams. The diodes is to prevent backflow of electricity causing the brake lights to be on all the time the headlights are, or making the running lights run when you push the brake. Any thoughts?

Originally Posted by DracoFelis

I think a better idea (and one I've considered, but haven't yet acted on) is a relay that comes on if the brake lights are on AND your car is "in gear" (not clutch in, and not in Neutral, "in gear"). The way I figure it, you really are "SLOWING DOWN" if you pressing on the brakes (however lightly) and the car is "in gear".

I thought about this some more and I think your idea is a better one for a hypermiller, or however that is spelled, because you guys are driving around with the pedal up doing your tricks. But it would still be charging when idle if you have the break on.

On my 1990 corolla it does not appear to be using more gas when charging at idle, the idle speed decreases as the load increases. A little bit for the lights and a little more when you push the lighter in. I dont think it could as the computer has no way to figure if it's charging or not. The car just sends a positive voltage to the alternator through the field connection. When you turn the key off it shuts down the field so the engine stops instead of continuing to run off alternator power

[swng]

Originally Posted by omgwtfbyobbq

BMW has something like this.

I think I have just come across an article on this subject:

http://news.en.autos.sympatico.msn.c...mentid=5044282.

[MakDiesel]

IIRC, Motortrend or Car and Driver wrote an article in the '80s back when the '84-87 CRX HF was still new and they listed several instances on why it got the awesome EPA mileage it did and one was that the alternator only charged when decelerating/braking unless the battery was at a critical level, lights on, etc . Worth looking up. I believe they were attempting to make a trip several hundred (550? 600?) miles on one tank of gas. Mak

[cfg83]

MakDiesel -

Originally Posted by MakDiesel

IIRC, Motortrend or Car and Driver wrote an article in the '80s back when the '84-87 CRX HF was still new and they listed several instances on why it got the awesome EPA mileage it did and one was that the alternator only charged when decelerating/braking unless the battery was at a critical level, lights on, etc . Worth looking up. I believe they were attempting to make a trip several hundred (550? 600?) miles on one tank of gas. Mak

It was the December 1983 issue :

Attachment 832
Attachment 835
Attachment 834

I still have the issue. I wanted a CRX soooo bad!!!!!!

CarloSW2

[GasSavers_veloman]

My brother had an early 90s CRX back in high school. We would spin the tires on that thing forever, made huge clouds of smoke. Great mpg of course. And it handled real quick too. I kind of wish I had one now instead of my larger civic.

Speaking of spinning the tires, I'm kind of suprised I can do it in my auto civic. I've done it unintentionally when pulling out onto a main road in traffic. It really doesn't take much throttle. If it's wet, forget it, you have to baby it.

It seems the civic has this "surge" when accelerating from a stop, about 2 seconds in. At first it's like dogging it, then it will jump, all with the same throttle. Overall, I really dislike the way my civic drives below 30mph. If am accelerating slowly, it seems like it doesn't want to shift at 25mph, especially if it's cold. I have to give it some more gas to get past that weird spot. Also, it has some crazy engine braking in 1st and 2nd gear, I can't coast in those gears. I know, I should just get a stick.

[koinos]

Honda developed the technology in 80s, I think that era was 2nd oil shock. And why we don't have that device for new cars thesedays.

Can we think about any 2nd market device that we can add to our cars? Some relays, switches, and/or clutch will do the job. The total cost would be not that much, I guess.

[FritzR]

I guess someone else is going to have to try this because if the 84 CRX HF does this already and the VX also, I bet my new '88 CRX HF already does this as well. I can't wait it will be out of the shop in 7 days with a rebuilt motor.


Can we think about any 2nd market device that we can add to our cars? Some relays, switches, and/or clutch will do the job. The total cost would be not that much, I guess.

If you just put a momentary switch to engage the field on the brake pedal and a diode over to the running lights to turn it on always at night you would be out less than $10.

+12V--switch-|----|<------------------------running lights
Alternator Field

It would be much better to use some kind of pulley with a clutch to stop the belt though. I searched and didn't find anything online but they must have something like that somewhere. Sure be nice to put one of those on the A/C too

[koinos]

So, looking up the HONDA CRX in 80s will guide us what to do. Anybody has the detail of the CRX alternator technology?

[koinos]

The reason I'm interested is, according to
http://www.metrompg.com/posts/alternator-optional.htm

This technology can give us 10&#37; boost in overall FE.

[GasSavers_Ryland]

I would think this would be easy to program in to a new car, as they already moniter manifold vaccum, battery voltage, engine speed, and everything else, I suspect that the CRX is monitering manifold vaccum insted of gas pedal position, alowing for a wider range that it would see as engine braking.