# NOT perpetual motion, altenator regen?



## lou-ace (Jul 21, 2009)

Alright now bear with me guys, it accured to me that since I'm utilizing the 9" ADC double shaft motor,and I'm not using the double shaft end for any purpose, why not use pullys and belts to drive an altenator ( free wheeling most of the time), coupled with switches so that when I hit the brakes it turns on the altenator, slows down the vehicle and acts as a form of regeneration. I've already been told that my series DC motor isn't suitable or designed for regen and I'm mostly interested in the range of my vehicle. I can imagine that even in the freewheeling state said altenator would decrease my range just by turning the shaft, but what of the regen. possibilities could they significantly increase my range? I do live in a little bit of a hilly regon as a matter of fact if i go one way from my house I immeadiatly asscend a 300-400ft hill, I would love to be able to recapture some of that expended energy on the other side of the hill with regen......... comments?


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## CrunchTime (Feb 13, 2009)

Note that I know what I'm talking about, but an alternator would only be making 12V, wouldn't it? Implying you might be able to recharge your accessory battery, but probably not your traction pack?


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## resago (Sep 28, 2010)

most factory alts are 55-80amp 13.8V output

not much regen there.

you CAN get larger alts, ex. 100amp, 250amp, but not sure its worth the cost.


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## redcelt007 (Oct 2, 2008)

Hopefully this didn't post twice. 
It is possible to obtain higher voltages from an automotive alternator. Try to find one that uses an external regulator. I got 80 volts from a late 80's- early 90's unregulated Chrysler alternator coupled to a 3000 rpm ac motor with 12 volts applied to the field coil of the alternator. I set this up on my workbench and connected the alternator's output to 5 discharged 12 volt batteries. This caused considerable drag on the alternator and ac motor. So some braking should occur. Don't yet know what running this for an extended period of time would do to the rectifying diodes.


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## JRP3 (Mar 7, 2008)

There are a few threads on the topic. Some have rewound an alternator for pack voltage charging. In most cases it's not worth it for the mile or two you might get back from regen.


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## jehan12413 (Feb 4, 2010)

If you look at ebay for a PMA (permanent magnet alternator) coil you will see several stator coils listed and they are not too expensive. Of course for this application you would not use a permanent magnet rotor as you want to be able to turn it off. The point is that some of these coils can put out well over 300 volts and a stock rotor can handle well over 12 v for short periods of time. The one thing to watch is the diodes, use the style alternator that uses the press fit ones on the plate inside the back as these can be easily replaced with 600 volt ones. I think that would be a 10si or 12si early model GM alternator.


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## DIYguy (Sep 18, 2008)

You don't want to use permanent magnet field as you could vary the regen by adjusting the field. You want to get a large truck alternator and rewind it for your pack voltage (bit higher). You want to mount an electric clutch on the front of the motor, you could use an AC clutch. Press a button, engages the clutch, drives the alternator. The braking from this set up can be quite strong. I will look up a link for you. This fellow did exactly what you want. I kept it as I was going to do this. I did mount the clutch...

Here u go.... http://www.waynesev.com/

Just look up the Regen Braking link on the left side....


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## JRP3 (Mar 7, 2008)

DIYguy said:


> The braking from this set up can be quite strong. I will look up a link for you. This fellow did exactly what you want. I kept it as I was going to do this. I did mount the clutch...
> 
> Here u go.... http://www.waynesev.com/


He's getting about 10 amps at pack voltage. I can barely feel 10 amps of regen in my car, and it won't give you any noticeable range. For all the work he put in he basically ended up with nothing as far as I can tell.


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## DIYguy (Sep 18, 2008)

JRP3 said:


> He's getting about 10 amps at pack voltage. I can barely feel 10 amps of regen in my car, and it won't give you any noticeable range. For all the work he put in he basically ended up with nothing as far as I can tell.


I actually spoke to Wayne about his little regen system a while back. He was quite happy with it and said that the braking was quite noticeable. I think the braking is the bigger asset for most ppl. He said he had to be careful in the winter as he could easily skid his back wheels.


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## JRP3 (Mar 7, 2008)

Maybe I'm missing something then, but 10 amps at 160 volts is 1.6KW or about 2 hp, doesn't seem like enough to cause a skid, except maybe on ice with bad tires. For range, unless you have a 10 mile downhill regenning at 10 amps you probably wouldn't get even a mile of range from that setup.

*I suppose the rear brakes plus 10 amps of regen could skid the wheels in the snow.


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## DIYguy (Sep 18, 2008)

ya, it's true.... the numbers are low for any significant braking...although I wonder if he is capturing his peak output. He does mention popping a 15 amp breaker a lot in the beginning. 
Wayne's words.... 
"I was surprised at the braking effect of the Regeneration System. The braking sensation is very strong, giving a strong addition to the power brakes of the S10".It was definitely a lot of work...but very kewl what he did...


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## JRP3 (Mar 7, 2008)

Maybe he's using the wrong shunt and it's under reporting the amps? But then he'd be blowing breakers all the time. Weird.


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## ruckus (Apr 15, 2009)

His video clearly shows and states 18 amps regen. 18a x 156v= 2800 watts!

2800w at 3000rpm is 6.5ftlbs.

Hard to say the exact torque being applied, but in 3rd gear it would be about 3:1 times the rear-end at about 3.5:1, so the torque applied is multiplied about 10X!

So that is ~65ft lbs.

Here in Montana, just tapping the brakes can cause sliding, so 65ftlbs would definately cause it under slick conditions.


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## JRP3 (Mar 7, 2008)

JRP3 said:


> *I suppose the rear brakes plus 10 amps of regen could skid the wheels in the snow.


And actually the video shows 177volts and a peak of 18 amps, so even more power than we calculated at 160V and 10 amps. Makes a bit more sense now, though I still doubt it does much for his range.


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