Automatic alternator cut out/regen braking

[ECONORAM]

I just need to monitor this thread. I had not considered this idea...it would have been ideal on my old VW Rabbit diesel.

[Rainh2o]

I thought thats what regulator did in a car, was charge the battery and respond to loads

[HeadlessNorseman]

some food for thought here may be that some ECU/fuel injection/ignition systems work crapily with under 14v. On one of my cars(i believe a toyota supra 3.0 na 5 speed) i took all the accesory belts off to see if i gained any power and the car did not run well at all on only 12 volts. Many misfires and less overall power above 3-4000 rpms. It may be fine at the lower rpms needed for cruising but someone may have more knowledge on this

[Piwoslaw]

Crosslinking from a new thread:
Honda Alternator with ELD

[Sularus]

Did anyone ever get this figured out? It appeared AX was close, but had a problem with the feedback loop built into the alternator. I was thinking about doing something similar, but I was unaware of the feedback loop residing within the regulator. There is always the option of going with an external regulator and removing the internal one. This woud allow for more fine tuning of the circuits. I will keep looking at things, especially if I can get a spare alternator and some wiring schematics.

[Daox]

I do this manually (havent read this thread in a while). I turn my alternator back on if I'm going down a hill. I hold my kill switch and open the throttle fully. You really don't slow down very fast doing it this way, and it works fine. I suppose I could automate it by hooking up my alternator field wire to a relay triggered by the brakes. I haven't done it since I don't really use the brakes that much.

[max_frontal_area]

Originally Posted by AXMonster

Shouldn't be as the charging wouldn't occur without the engine turning

not all P&G is done with the engine off! hard to start engines are sometimes best left running

[asimmons04]

Originally Posted by s2man

My thinking too. I'd put the microswitch on the throttle. 0 throttle = charge. Besides charging while decelerating, that would also charge during my neutral coasts on the hills where the stupid a/t is pushing the rpm's up around 1100. I'd also add a parallel switch so you can energize at will (eg the battery is low, headlights or fan on, etc).

only thing about attaching to throttle is for a manual shift, your fully releasing throttle quite a bit during shifting, and it would kick the alternator in for like a second at a time jolting in and out of action. idk if thats good for the alternator but pretty sure the ecu would freak out or you'd blow something...

thats why im only having it cut on when either:
1. brake lights are on --->relay
2. Headlights are on------>same relay wire
3. manual switch -------->same relay wire, spliced in.

either one, some, or all, of the three will engage alternator, through the same relay.

the headlight wire is convenient so you will have a constant charge coming on under load like at night.

[Joenavy85]

Originally Posted by max_frontal_area

not all P&G is done with the engine off! hard to start engines are sometimes best left running

or AT equipped cars that will kill the tranny if the engine isn't running. no running engine = no ATF flow

EDIT: unless you have an old Chrysler 300 or similar with the pump on the tranny output shaft

[some_other_dave]

There are other AT-equipped vehicles that you can coast with the engine off without destroying the trans. The key words to look for in the owner's manual are "flat towing". If the car can safely be towed with all four wheels on the ground, then it is safe to coast with the engine off. If it cannot be towed with the drive wheels on the ground, you're taking chances if you do engine-off coasting.

-soD