Prius PHEV with Aftermarket Brake Rotors and Pads | Regen energy gained while braking rate increased

Sure. Go ahead and be excited. But please post how you are going to run a careful scientific experiment and what you are going to measure before you do it so there is no question that you are really measuring more regen.
This means multiple runs with and without the proposed new brakes over the same course with round trips to negate the effects of hills, wind, etc.
I'm looking forward to reading how you are going to run the tests and then seeing the data afterwards.

Mike

 

Great! But what is all the data? What, exactly will you analyze after you've collected it?
How many runs will you do with old and new brakes?
How many miles per run?
Will you do a warm up before each test?
Will you account for tire wear and pressure?
Will you be measuring outside air temp, wind, humidity -- I've not seen an OBD that collects this

You should probably wash the car between runs since this probably has as much effect on regen as the brakes

Mike

 

Fair enough, but you failed to answer all the other questions, such as how long is a run?
10 miles with the new brakes and 1 mile with the old brakes will normally show a much larger kwh value for the new ones.
I'd like to see a complete description of how you plan to test in a controlled manner.
And all the "other" things you'll document...air temp, tire pressure, elevation change,etc.
Using a scientific test allows others to repeat the same ~exact test and see if they get the same results.

Mike

 

Has anyone else noticed that regen appears to get used faster than charge from the wall, or is that just me.
Eyeballing gauges in the Prime it appears that going up hill the Prime used 4x the amount of energy as can be gained from regen going down the same hill at approximately the same speed.
Not that these observations have anything to do with aftermarket slotted rotors and ceramic pads, but I thought I'd offer some regen points that I've noticed, however inaccurate they might be.

 

I believe I read that regen captures about 30% of the energy used to create that speed...so it sounds like if you're going up and then down the same hill...well that sounds about right?

 

Genuinely not trying to make things harder for you, but when you're trying to figure out if an intervention (aftermarket rotors/pads) is effective compared to the control (OEM rotors/pads), a critical factor in experiment design is the order in which trials are conducted.

If your brakes were dragging before, there would be less kinetic energy left over for the regenerative system to recover than a well-lubricated system. In the process of swapping out the rotors you might end up relubing the caliper pins, thereby making a larger fraction of kinetic energy available to be recovered by regen. Since you were not specifically controlling for the effect of lubrication, your readings would seem to indicate greater regen after than before, and you might chalk it up to the slotted rotors when it was actually the lubrication doing the work. Randomizing the order of conditions or matching them (alternating between OEM and aftermarket brakes repeatedly, instead of all OEM followed by all aftermarket) makes it much less likely that confounding, unaccounted-for factors, such as brake drag, will skew your results one way or the other.