10 ms·

I didn't think about regenerative breaking and of course it looks like a good place. But in the end of the cannot this be absorbed by the batteries with a good

I didn't think about regenerative breaking and of course it looks like a good place. But in the end of the cannot this be absorbed by the batteries with a good configuration? I mean, adding N supercapacitors that can absorb X power each would be proportional as configuring it as M batteries (where M >> N) charging that can absorb Y power each where Y = X * N / M => Y << X, which seems doable. So you'd either need enough capacitors to use them effectively (adding cost/complexity) or enough batteries, right? Is that the reason why Tesla can do regenerative braking except for strong stops? Because the batteries can absorb part but not all of the sudden energy?

jon_richards 10y ago
I imagine the strong stop problem is more about actually stopping the car fast enough. Easier to do with friction than induction.
- marcosdumay 10y ago
  That will depend on your speed. High speeds favor inductive braking. Anyway, if I were to guess, I'd say it's because ABS tech is very mature, and inductive breaking is not, thus safety favoring friction.
Retric 10y ago
Battery's don't really like very short partial charge cycles, and the electronics to track these energy spikes get's difficult. Storing ~e6 J in ~5 seconds takes a lot of battery's. Also of note, because battery systems can only take X energy the rest of the system is only disguised to supply X energy. Most hybrids use battery's and simply kick in normal breaks if you do more than a slow stop. But, with super cap's a lot of this goes away. They can store more energy so you can add larger alternators and recover more energy. Further, they have a higher % efficiency for charge / discharge cycles.
- Roboprog 10y ago
  So, you have 3 tiers of rate vs capacity? * Capacitor - high charge / discharge rate (power), low capacity (total energy). (and high risk of electrocution and spot welding) * Battery - medium power, medium capacity. * Small ICE - low power, high capacity.

jon_richards 10y ago

I imagine the strong stop problem is more about actually stopping the car fast enough. Easier to do with friction than induction.

marcosdumay 10y ago
That will depend on your speed. High speeds favor inductive braking. Anyway, if I were to guess, I'd say it's because ABS tech is very mature, and inductive breaking is not, thus safety favoring friction.

Retric 10y ago

Battery's don't really like very short partial charge cycles, and the electronics to track these energy spikes get's difficult. Storing ~e6 J in ~5 seconds takes a lot of battery's. Also of note, because battery systems can only take X energy the rest of the system is only disguised to supply X energy. Most hybrids use battery's and simply kick in normal breaks if you do more than a slow stop. But, with super cap's a lot of this goes away. They can store more energy so you can add larger alternators and recover more energy. Further, they have a higher % efficiency for charge / discharge cycles.

Roboprog 10y ago
So, you have 3 tiers of rate vs capacity? * Capacitor - high charge / discharge rate (power), low capacity (total energy). (and high risk of electrocution and spot welding) * Battery - medium power, medium capacity. * Small ICE - low power, high capacity.