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Discussion Starter #1
How on earth could Smart let this go from their programming? When I set the paddles on level 2 I brake as hard as someone pushing on their brake pedal and yet no one behind knows this because Smart didn't program that into the system. Seems like a huge safety issue to me. My wife watched as I jetted away and let off the accel and had the regen kick in. No lights :(

Anybody have a hack out there for this? Without actually having to use the brake pedal? :)

Bobby


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As an owner of a 14ED I have thought about this alot. Usually when I see some idiot behind me texting and almost rear ending me because my brake lights aren't on. I do think of it as a safety issue. However, how do you solve it? Current laws on brake lights are centered around the brakes being actuated. Regen is technically not the same as braking. My idea for the future would be to have two-stage brake lighting. So the brake lights come on dimly when regening and then fully when braking. Just my 2 cents.
 

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That other thread got into a pissing match about what and what not a paddle-less vehicle can do. I sought out a paddle version specifically and I *love* it! I wouldn't want it any other way but the brake lights NOT engaging is asinine


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I sought out a paddle version specifically and I *love* it! I wouldn't want it any other way but the brake lights NOT engaging is asinine.
Yup, and to your "opinion" just trying to point out that this has been questioned by some since 2013 and - no "hack" has been suggested. :shrug:
 

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Table I-a—Required Lamps and Reflective Devices

NHTSA has given it some thought and buried in a chart in Title 49 of the Code of Federal Motor Vehicles Safety Standards they specify . . .

STOP LAMPS - Must be activated upon application of the service brakes. When optically combined with a turn signal lamp, the circuit must be such that the stop signal cannot be activated if the turn signal lamp is flashing.

May also be activated by a device designed to retard the motion of the vehicle.


https://www.ecfr.gov/cgi-bin/text-i...56e89de&mc=true&node=se49.6.571_1108&rgn=div8
 

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This subject has been mentioned more recently. Here’s what it boils down to:

The best hack you’re going to get right now is something like a GearBrake. Essentially, you’ll be adding a motion sensor to your brake lights that will trigger illumination when you slow down.

https://gearbrake.com

The big problem is that the SAM unit will not be fond of this gadget. I guess you could install auxiliary lights and connect the GearBrake to them. You could also try an in-line resistor, but that may impact the GearBrake’s performance.

This thing works with the SAM...but it’s a motorcycle license plate holder.

https://www.amazon.com/gp/aw/d/B00MEQ25X8/ref=cm_cr_arp_mb_bdcrb_top?ie=UTF8

This also works with the SAM, but will not fit in the smart’s existing brake lamp housings.

http://www.mechoptix.com/stoptix-auto/
 

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The regen is so strong you can basically use it to almost fully stop the car, only needing to apply brakes at the last moment.
 
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The regen is so strong you can basically use it to almost fully stop the car, only needing to apply brakes at the last moment.
"so strong" - in a smart ED?

With regeneration paddles, single pedal EV driving is doable in light, predictable, stop and go traffic. Similar results can be had without paddles but as with all things smart - YMMV.

Note, regen is non-existent if your HV battery is at 100%. Also, drive torque and regen (drive motors becomes generators) can cause additional wear ED's rear tires.

Tesla (and others) utilize an accelerometer that triggers the brake lights to illuminate if the force of deceleration exceeds a certain number(?) of G's.

Apparently the following International Rules are followed by most manufacturers?

http://www.unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/R13hr2e.pdf

The relevant paragraph that refers to regen brakes and stop lights is 5.2.22.4 (page 22) which lists deceleration limits for regen.


Below 0.7M/s/s (Meters per second per second, or per second squared) the requirement is for NO STOP LIGHTS.
Between 0.7M/s/s and 1.3M/s/s stop lights are optional, "The signal may be generated."
Above 1.3M/s/s STOP LIGHTS ARE REQUIRED, "the signal shall be generated," i.e. STOP LIGHTS SHOULD BE LIT.


Most EVs with a strong (NOT smart) regen mode work this way, and Tesla's vehicles are no exception.
 

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What's the difference between regenerative braking not activating the brake lights and,
gearing down and using engine braking which also doesn't activate the brake lights...?
Similar in "concept" BUT EV regeneration generally provides more aggressive "braking" (with motor reversing to generator resistance) than the downshift braking of today's smaller displacement ICE engines.

EV stop light regen guidelines (no such for ICE downshifting) go like this . . .

1) Some deceleration is minimal to the point that a brake light is not allowed.
2) There's a window of deceleration where a brake light is optional.
3) Finally, there's strong enough deceleration that a brake light is required.
 

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I wasn't referring to the brake light activation (since when does the U.S. DOT follow United Nations regulations?)
rather, to brake lights not being visible to drivers behind. My 2017 ED doesn't regenerative brake anywhere near as aggressively
as my 2003 Nissan Altima 3.5 l V6 does when shifted down to second gear both, traveling downhill at 50 mph...
 

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What's the difference between regenerative braking not activating the brake lights and,
gearing down and using engine braking which also doesn't activate the brake lights...?
Yeah. But in this age of near-extinction of the manual transmission, who has heard of that?
 

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"so strong" - in a smart ED?

With regeneration paddles, single pedal EV driving is doable in light, predictable, stop and go traffic. Similar results can be had without paddles but as with all things smart - YMMV.

Note, regen is non-existent if your HV battery is at 100%. Also, drive torque and regen (drive motors becomes generators) can cause additional wear ED's rear tires.

Tesla (and others) utilize an accelerometer that triggers the brake lights to illuminate if the force of deceleration exceeds a certain number(?) of G's.

Apparently the following International Rules are followed by most manufacturers?

http://www.unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/R13hr2e.pdf

The relevant paragraph that refers to regen brakes and stop lights is 5.2.22.4 (page 22) which lists deceleration limits for regen.


Below 0.7M/s/s (Meters per second per second, or per second squared) the requirement is for NO STOP LIGHTS.
Between 0.7M/s/s and 1.3M/s/s stop lights are optional, "The signal may be generated."
Above 1.3M/s/s STOP LIGHTS ARE REQUIRED, "the signal shall be generated," i.e. STOP LIGHTS SHOULD BE LIT.


Most EVs with a strong (NOT smart) regen mode work this way, and Tesla's vehicles are no exception.
That’s a wonderful (and unexpected) lesson! Thanks!

Essentially, there’s nothing wrong with how the ED works as it likely abides by current international standards.
 

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What's the difference between regenerative braking not activating the brake lights and,
gearing down and using engine braking which also doesn't activate the brake lights...?
My thought exactly. I can downshift a manual transmission vehicle to almost a full stop quite rapidly with out activating the brake lights.
 

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As a data point, the last time I data logged a track driving day, I achieved a peak deceleration of 0.33G or 3.3 m/s^2 from 6000 rpms down to about 4800 rpms in second gear just from engine braking and aero drag alone. Decel would have been greater in first gear. With a paddle shifted transmission that does rev matched downshifts, these are easy and frequent events even during brisk street driving.
 
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