Not enough regen braking

Cold weather really puts a damper on regent braking. Try setting your charge level lower and use scheduled departure. Parking car in garage helps too.

 

There are at least 3 different levels of reduced regen (which you can readily observe on the energy/regen bar on the display), and the reduced regen warning only pops up when regen is almost at 0. Which requires temps near or below freezing, in my experience.

 

I just got the warning. Parked outside. Temp in 50s. Needed to brake for a few times but it got better after a while...

 

Can someone explain how outside temps reduce regenerative braking?

 

Sure. Cold outside temperatures mean cold battery temperature after the car has been parked. Lithium ion batteries can’t charge when their temperature is below freezing. Regeneration starts to taper off as the battery temperature approaches decreases. Regen will be restored as the battery warms up either through driving or through active heating.

 

Just a reminder from the Model S Manual (Page 66, 10/30/19 version, 2019.36.1) about Regen braking, especially for those in cold and snowy climates:

"Warning: In snowy or icy conditions Model S may experience traction loss during regenerative braking, particularly when in the Standard setting and/or not using winter tires. Tesla recommends using the Low setting (see To Set the Regenerative Braking Level on page 66) in snowy or icy conditions to help maintain vehicle stability.

The Energy app displays real-time feedback on the amount of energy being gained by regenerative braking. You can also display the power meter on either side of the instrument panel by choosing Energy using the scroll button on the steering wheel (see Steering Wheel on page 44).

The amount of energy fed back to the Battery using regenerative braking can depend on the current state of the Battery and the charge level setting that you are using. For example, regenerative braking may be limited if the Battery is already fully charged or if the ambient temperature is too cold.

Note: If regenerative braking is limited, a dashed yellow line displays on the power meter."

 

Yes, Tesla has cocked up firmware recently.
>4°C cell voltage makes the BMS deny any charging
and
then fuc*d up preheating, even if it's cold outside and you preheat for an hour, the coolant heater is NOT on, so the trip starts with cold battery.

I reported it via service center, who knows if or when tesla gets the message, but it is annoying as H here north.

 

I see a warning icon next to the energy readout only when regen limits are about to end. What is up with that?

 

I think everyone who isn't in the far south is seeing this. The power meter shows you a dashed line indicating regen is limited and how much it is limited. I don't recall if there is a warning message, although that would be a good idea. That first time you take your foot off the gas pedal and the car keeps careening towards the stop sign or red light is a bit unsettling. Heck the Navigate on Autopilot makes me acknowledge that I could move to a different lane. Why not a warning message and acknowledgement when you start the car before you start driving?

 

Minnesota here. I went thru last winter with my model 3. The car is garaged when not in use and will still not see full regen until next April due to our cold. Just normal to fully protect the battery. Btw, the ability to pre warm my car and the seats up here is golden. It’s a great cold weather car.

 

Model 3 forum and the 3 doesn’t have a battery heater.

 

Not sure what you are trying to say. The model 3 does have a battery heater. It is the motor. The run the motor in a way that makes heat without turning the wheels. The cooling system removes the heat from the motor and uses it to warm the battery. It may not be a separate electric heater, but it is still an electric heater.

 

Would scheduled departure help with regen if the low temps are in the 40/50s?

 

Short drive to store yesterday, its about 4C outside, car was garaged, fully charged.
On the way back home, down a 10% grade road, there was no regenerative braking at all.
You could really feel how heavy the car is as it tries to accelerate going downhill under its own weight.
Its quite a shock to experience when your used to generative braking.

 

I live in Los Angeles and I get the regen warning.

 

Our Tesla that parks inside the garage never got regen warning. The one that parked outside got it every morning. Our garage is pretty warm though.

 

For the man that needs more projects....Elon!
a Battery Heating Blanket for cold climates!