Shake generators
 

I was curious about regen shocks when the article came up a while ago. I was more interested when Mazda developed an reclaiming system for their new vehicles. It got me thinking about similar devices I had that cost near nothing.

I used to have a flashlight that you could shake to power, it had a large capacitor to store power and was so incredibly simple. The problem was that it was made out of cheap plastic and thinner than hair wire.
I was thinking that a small neodymium magnet (something like a bucky ball or bulk set of little cubes) in a container with a spring at either end of the tube might be a good idea. The spring would hopefully keep it from eventually smashing the container apart, but also keep it quieter and help keep it in motion. It could possibly even be a rolling design, doesn't have to bounce up and down.
I'm not sure where best to safely mount such a thing. Maybe a row in the engine bay. Maybe they could be kept safely on the wheel struts. I wonder if it would be worth the effort.
Shake-A-Can Generator : Shake

What other 'shake' designs come to mind? Calculating the size and shape is one thing but everyone's roads are different.

4 day with no response? You deserve better.

If your input is a pure sinusoidal curve, you gain (some % of the wasted energy). But as soon as the input is chaotic the gain would disappear in the noise, as the magnets lose synch with the car body. Calculate the size of the magnets and coil to instantaneously absorb one pothole. Then divide by the % of time that instant is.

HTH

I have a couple of LEDs which shine quite bright if you hook them up with a 9V battery and a 4.7 kOhm resistor in series. So they use less than 5 mW to shine that bright.
If your shake generator produces 5 mW continuously it will produce enough energy in an hour to make your turn signals blink once. Like not twice.

You need to scale up the shake generator about 100.000 times to be able to do away with the alternator. By that time I fear it will outweigh the car.