3 ms·

BTW brakes are dead simple. Fixing them is a task any self respecting person should be able to do. Au contraire. An EV uses a combination of traditional frict

BTW brakes are dead simple. Fixing them is a task any self respecting person should be able to do. Au contraire. An EV uses a combination of traditional friction braking and regenerative braking, with a sophisticated algorithm to appropriately shift between methods. If the batteries are fully charged, that means less regenerative braking. If a vehicle is driven aggressively the batteries are probably already hot, so less energy should be dumped back into them when braking. But at the same time, the friction brakes are probably being overused. How to keep them from being destroyed? What if a car is yawing or drifting? When stability control kicks in, some combination of friction braking and regenerative braking may be warranted. How much at the front axle, how much at the rear axle, how much at each wheel? If this were "dead simple", why did Formula 1 teams need a few years to work out their braking issues at the start of the current turbo hybrid era? We're no longer in the days of a master cylinder responding to pressure from a driver's foot by simply sending hydraulic fluid to drum brakes. Sure, simple maintenance such as replacing brake pads in most cars can still be DIY. But "repair" in general is no longer simple.

Animats 8y ago
That's a good point. Remember when Tesla reduced braking distance with an over the air software upgrade? Unlike locomotives and street cars, few electric cars have a resistor bank for dumping braking energy when the batteries are fully charged. So a fully charged battery does reduce braking performance.
perl4ever 8y ago
"We're no longer in the days of a master cylinder responding to pressure from a driver's foot by simply sending hydraulic fluid to drum brakes." I think there are many cars on the road that literally fit that description, and certainly it's still legal to drive such. More cars that you'd think have rear drum brakes. The complexity of electronic aids is not really germane to the complexity of maintaining brake systems when you normally don't get failures and if you do there's going to be a code that tells you.
- PhantomGremlin 8y ago
  More cars that you'd think have rear drum brakes. Sure, legacy. But this entire discussion started with Tesla. Which has a much more sophisticated system. Even the entry level current generation Honda Civic LX has 4 wheel disc brakes (which, granted, aren't much different than drums). not really germane to the complexity of maintaining brake systems The poster I responded to said "fixing them". I consider that to be much different than your word "maintaining". Maintaining is much easier than fixing. Tesla probably keeps their codes secret and won't sell you any replacement electronic parts anyway. The practical result of this is IMO quite the opposite of "dead simple".
- rightbyte 8y ago
  ""We're no longer in the days of a master cylinder responding to pressure from a driver's foot by simply sending hydraulic fluid to drum brakes."" At some point of actuation the Tesla car should have a mechanical backup when depressing the brake pedal, right? I really don't think it's pure brake by wire.

Animats 8y ago

That's a good point. Remember when Tesla reduced braking distance with an over the air software upgrade? Unlike locomotives and street cars, few electric cars have a resistor bank for dumping braking energy when the batteries are fully charged. So a fully charged battery does reduce braking performance.

perl4ever 8y ago

"We're no longer in the days of a master cylinder responding to pressure from a driver's foot by simply sending hydraulic fluid to drum brakes." I think there are many cars on the road that literally fit that description, and certainly it's still legal to drive such. More cars that you'd think have rear drum brakes. The complexity of electronic aids is not really germane to the complexity of maintaining brake systems when you normally don't get failures and if you do there's going to be a code that tells you.

PhantomGremlin 8y ago
More cars that you'd think have rear drum brakes. Sure, legacy. But this entire discussion started with Tesla. Which has a much more sophisticated system. Even the entry level current generation Honda Civic LX has 4 wheel disc brakes (which, granted, aren't much different than drums). not really germane to the complexity of maintaining brake systems The poster I responded to said "fixing them". I consider that to be much different than your word "maintaining". Maintaining is much easier than fixing. Tesla probably keeps their codes secret and won't sell you any replacement electronic parts anyway. The practical result of this is IMO quite the opposite of "dead simple".
rightbyte 8y ago
""We're no longer in the days of a master cylinder responding to pressure from a driver's foot by simply sending hydraulic fluid to drum brakes."" At some point of actuation the Tesla car should have a mechanical backup when depressing the brake pedal, right? I really don't think it's pure brake by wire.