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> Nondeterministic regenerative braking as described here seems like a serious bug in a vehicle I wouldn't call it nondeterministic, there's a notification win

> Nondeterministic regenerative braking as described here seems like a serious bug in a vehicle I wouldn't call it nondeterministic, there's a notification window alerting you to the limited reg and there's a "gauge" below the "speedometer" that shows power input/output. That being said, it's bad UX/UI and they could do a better job representing it. The power gauge is a hair thin line with no labels or scale that you must intuit the purpose of by observation. The Gen1 Leaf isn't really better, it's just different. Theere's again a power gauge that shows power input/output. You can clearly see the scale of the gauge which is better but again you must observe it to understand it's purpose. The Leaf also has rings around each tic in the gauge that denotes if that level is accessible. When the batter approaches 100% charge or it's terribly cold you lose rings on the input side of the gauge and when the battery is exceptionally low you lose them from the output side. Again it's nice if you know what it means but the only way to know is through observation of the gauge. I'm guessing other EVs aren't any better. We're probably going through a phase much like early automobiles where each manufacturer comes up with novel UIs to complete the feedback loop between car and driver. Eventually they'll all standardize on something universally understood.

sokoloff 8y ago
> Again it's nice if you know what it means but the only way to know is through observation of the gauge. Or you could read the LEAF's fine owner's manual. Search for "Power Meter" and it's described perfectly clearly.
- cptskippy 8y ago
  > Or you could read the LEAF's fine owner's manual. Search for "Power Meter" and it's described perfectly clearly. That doesn't dismiss the fact that the Power Meter is poor UI/UX. In most other cars the instrument cluster has clear labels and/or iconography that's identifiable. Even in the Leaf there are signs of thoughtful design, Nissan adapted the standard Fuel Gauge Icon with a Power Plug pigtail to indicate the Battery Level Gauge, though bizarrely it also includes an incorrect port indicator, and they put a battery capacity gauge right alongside the battery level gauge to clearly differentiate the two AND show that they're related. The Power Meter is fusion of two gauges (i.e. power input/output and available input/output) and there should have been a clearer delineation instead. It's easy enough to infer that the Power Meter is analogous to a Tachometer after observing it for a few minutes but it takes longer to understand the regenerative braking aspect. The disappearing rings based on Temp/Capacity of the Battery are a much harder thing to understand.
Someone 8y ago
From a human factors perspective, whether you can know what it will do isn’t sufficient. What matters is whether you will know when it matters, even if you’re tired or distracted and panicking because you’re rapidly approaching a kid that stepped onto the road. I would expect the likes of Volvo to make the traditional brakes pull in when regenerative braking lacks power. They tend to have a huge human factors department.
- cptskippy 8y ago
  Regenerative Braking comes in two forms, passive and active. The notifications regarding limited Regenerative Braking Capacity are specific to passive braking (e.g. backing off the accelerator, lifting your foot off all pedals). Active braking will working using either Regenerative Braking or traditional brakes so what it's doing is irrelevant as the behavior is identical to the user. So in your scenario where an individual might need to actively brake, they would be able to without issue. Where it might be an issue is when you're driving in bumper to bumper traffic and you're expecting regenerative braking and it's not there and you roll into the car in front of you. Then again, you don't make it very far down the road without noticing a difference in the accelerator pedal characteristics in limited regen mode.
  - Someone 8y ago
    The way I understand this is that, most of the time, users will be braking by removing pressure from pedal A, and only in exceptional cases they would have to do it by applying pressure to pedal B. If so, I think you cannot expect humans (most of them even amateur drivers) to make that switch under stress, no matter how well you signal that the car requires you to use mode B.
    - cptskippy 8y ago
      The Gen2 Nissan Leaf has an "e-pedal" that works differently so I can't speak for that, but for the Gen1 Leaf and a 2018 Model 3 you absolutely use the brake pedal. The difference is that Regenerative Braking just changes your timing when switching from Accelerator to Brake, it doesn't eliminate it entirely. Have you driven a standard transmission ICE? Downshifting into a lower gear is a very similar experience to regenerative braking. It's an aggressive deceleration that will slow the car from high speeds but it's no replacement for actual brakes. For someone inexperienced with an EV, the lack of Regenerative Braking would feel like driving a normal car. For someone familiar with it, you're immediately aware of it's absence. In an ICE you coast by taking your foot of the accelerator, in an EV you coast by applying 10% pressure to the pedal (I made that % up). The reason you need 10% pressure to coast is that anything under that amount is where regenerative braking functions. So there's a weight to the pedal that isn't there when regenerative braking is gone. It's hard to explain without driving an EV but it would be like using a computer mouse without the scroll wheel. You're keenly aware of it and if it's not there.

sokoloff 8y ago

> Again it's nice if you know what it means but the only way to know is through observation of the gauge. Or you could read the LEAF's fine owner's manual. Search for "Power Meter" and it's described perfectly clearly.

cptskippy 8y ago
> Or you could read the LEAF's fine owner's manual. Search for "Power Meter" and it's described perfectly clearly. That doesn't dismiss the fact that the Power Meter is poor UI/UX. In most other cars the instrument cluster has clear labels and/or iconography that's identifiable. Even in the Leaf there are signs of thoughtful design, Nissan adapted the standard Fuel Gauge Icon with a Power Plug pigtail to indicate the Battery Level Gauge, though bizarrely it also includes an incorrect port indicator, and they put a battery capacity gauge right alongside the battery level gauge to clearly differentiate the two AND show that they're related. The Power Meter is fusion of two gauges (i.e. power input/output and available input/output) and there should have been a clearer delineation instead. It's easy enough to infer that the Power Meter is analogous to a Tachometer after observing it for a few minutes but it takes longer to understand the regenerative braking aspect. The disappearing rings based on Temp/Capacity of the Battery are a much harder thing to understand.

Someone 8y ago

From a human factors perspective, whether you can know what it will do isn’t sufficient. What matters is whether you will know when it matters, even if you’re tired or distracted and panicking because you’re rapidly approaching a kid that stepped onto the road. I would expect the likes of Volvo to make the traditional brakes pull in when regenerative braking lacks power. They tend to have a huge human factors department.

cptskippy 8y ago
Regenerative Braking comes in two forms, passive and active. The notifications regarding limited Regenerative Braking Capacity are specific to passive braking (e.g. backing off the accelerator, lifting your foot off all pedals). Active braking will working using either Regenerative Braking or traditional brakes so what it's doing is irrelevant as the behavior is identical to the user. So in your scenario where an individual might need to actively brake, they would be able to without issue. Where it might be an issue is when you're driving in bumper to bumper traffic and you're expecting regenerative braking and it's not there and you roll into the car in front of you. Then again, you don't make it very far down the road without noticing a difference in the accelerator pedal characteristics in limited regen mode.
- Someone 8y ago
  The way I understand this is that, most of the time, users will be braking by removing pressure from pedal A, and only in exceptional cases they would have to do it by applying pressure to pedal B. If so, I think you cannot expect humans (most of them even amateur drivers) to make that switch under stress, no matter how well you signal that the car requires you to use mode B.
  - cptskippy 8y ago
    The Gen2 Nissan Leaf has an "e-pedal" that works differently so I can't speak for that, but for the Gen1 Leaf and a 2018 Model 3 you absolutely use the brake pedal. The difference is that Regenerative Braking just changes your timing when switching from Accelerator to Brake, it doesn't eliminate it entirely. Have you driven a standard transmission ICE? Downshifting into a lower gear is a very similar experience to regenerative braking. It's an aggressive deceleration that will slow the car from high speeds but it's no replacement for actual brakes. For someone inexperienced with an EV, the lack of Regenerative Braking would feel like driving a normal car. For someone familiar with it, you're immediately aware of it's absence. In an ICE you coast by taking your foot of the accelerator, in an EV you coast by applying 10% pressure to the pedal (I made that % up). The reason you need 10% pressure to coast is that anything under that amount is where regenerative braking functions. So there's a weight to the pedal that isn't there when regenerative braking is gone. It's hard to explain without driving an EV but it would be like using a computer mouse without the scroll wheel. You're keenly aware of it and if it's not there.