NHTSA Complaint wrt Regen and TC

[James]

I heard that this NHTSA complaint was false.

Tesla Motors checked with every owner that was within the listed VIN series and none of them filed this complaint.

[doug]

Moderator's Note -- The somewhat off topic discussion about regen went here: http://www.teslamotorsclub.com/techn...ll-charge.html

[TEG]

Is the regen basically an "all or nothing" affair?
Perhaps it would be less noticed if it "feathered" in and out?
When TC computer decides regen has to stop perhaps it could "dim" it out over a second rather than off in an instant?

Like the way modern MP3 players will fade out a track and fade in the next when you change tracks. Older players tended to just jump harshly to the new track.

[doug]

I heard that this NHTSA complaint was false.

Tesla Motors checked with every owner that was within the listed VIN series and none of them filed this complaint.

That's certainly possible. Anyone can file such a complaint and it appears to be from just one person. Probably don't even have to prove ownership. The partial VIN listed includes the check digit so there are likely at most 50 owners to contact.

Then again the description is rather specific and sounds like an owner over reacting to a designed behavior of the TC. Is there a published finite state diagram for the TC so drivers know what to expect in a given situation?

[vfx]

That's certainly possible. ...
Then again the description is rather specific and sounds like an owner ...

*Conspiracy Alert!*

Could be a competitor who knows enough about cars to have fabricated a story. There are other enemies, Big Oil, Hydrogen, TTAC, Honda...

[tomsax]

I heard that this NHTSA complaint was false.

Tesla Motors checked with every owner that was within the listed VIN series and none of them filed this complaint.

Since Tesla does have a bit of a reputation for being, shall we say, heavy handed with customers who they perceive to be complainers, I'm not sure I believe their calling up customers asking them to fess up would be 100% effective in identifying the responsible party.

[doug]

At least the manual mentions it:

You’ll also experience a loss of regenerative
braking in slippery road conditions—when
this occurs, the traction control indicator on
the instrument panel may flash and you may
experience that the brakes feel slightly
different. This is not a cause for concern.

[raymond]

I believe I have experienced this effect...

So the NHTSA report may or may not be fake, but the effect seems to be there.

What is the max. regen braking? I've seen 0.2G somewhere. What would it feel like if you suddenly (within a millisec) lost 0.2G braking? Can than be mistaken for an acceleration / jolt in the back?

Wouldn't be surprised if it did.

[speedy99]

It does actually make sense for the traction control to reduce regen. Perhaps it shouldn't completely kill it like this owner describes. I can see how it might be a bit disconcerting (as it is when you lose regen because of a full battery). I don't, however, think it should be a problem if the driver is aware of it.

Another datapoint. My 2nd gen Prius and 1st gen highlander hybrid both act this way. Regen is killed even under light to moderate braking if you hit a bump or slippery patch - before ABS kicks in. Regen stays off until you stop braking and acceleration again. Easy to reproduce, but not unexpected or startling once you get used to it. Makes perfect design sense, but it can be unsettling the first time it happens. Ridiculous to file a complaint about it...

[smorgasbord]

If you live in Northern CA, you can reproduce the effect thusly:

1) Get on 280 North at Page Mill or further south.
2) Exit at Alpine at freeway speed
3) Use regen to slow down
4) Stay in the rightmost lane for a right hand turn
5) When the pavement changes from asphalt to concrete, regen will temporarily disable

If you're not expecting it, it's quite disconcerting.