Regen braking capped at charging level or battery capacity?

[kman42]

I think I understand this, but just want confirmation. I’ve noticed that I get the regen braking reduced message a few minutes after starting every drive in the morning (I live on the top of a small mountain/ big hill). I know this can occur when the battery is near capacity, but I’m only charging to 85%. Is it the case that regen braking actually uses the charging cap rather than 100% battery capacity as its threshold?

 

[Grabthar]

It also depends on temperature. In cold weather, you can get limited regen at even lower SoC

 

[wynnek]

I think I understand this, but just want confirmation. I’ve noticed that I get the regen braking reduced message a few minutes after starting every drive in the morning (I live on the top of a small mountain/ big hill). I know this can occur when the battery is near capacity, but I’m only charging to 85%. Is it the case that regen braking actually uses the charging cap rather than 100% battery capacity as its threshold?

I don't think it uses the charging cap because I regularly charge to 75%, but never see that message.

 

[Fourdoor]

Yeah, somewhere between 85% and 90% (in warm weather) is where you start getting that message, it doesn't mean regen is eliminated, just that it is reduced, and the left edge of the left bar will be dots instead of being solid... the higher your state of charge goes the more dots / less solid line you have indicating that you have less regen available.

Keith

 

[Land Shark]

Try limiting charge to 80% and let us know.

 

[SpicyPaneer]

I get the same message at 79% charge on cold days at 32f after the new software update. I never had this issue prior to the new software update. I feel the new regen systems is not grabbby when you let go of the accelerator pedal. Seems it has a more coasting vs jerky slow down.

 

[jjrandorin]

Is it the case that regen braking actually uses the charging cap rather than 100% battery capacity as its threshold?

No, it doesnt use the charging cap as a regen threshhold. It limits regen to protect the battery from being charged at full regen for a variety of reasons, like temperature of the battery, or capacity of the battery.

 

[240vPlug]

Right there are different scenarios where Regen will be limit. One less common case is when you doing a lot of hard acceleration and hard Regen. The more you do that you may notice Regen is limited.

Most common cause of limited Regen when charged <90% are cooler temps. I notice it below 45-50 F . The colder the temps the more it's limited.

Lastly at a high state of charge the battery is limited in the rate of charge and so also Regen to protect the battery.

 

[kman42]

Switched to 80% charging cap instead of 85% and haven’t seen it again.

 

[kman42]

Somewhat related question. Does regen breaking use Tesla vision or USS to stop for cars in front of you, stop signs, or lights? I.e. does it use its sensors to adjust the rate of stopping?

 

[240vPlug]

Somewhat related question. Does regen breaking use Tesla vision or USS to stop for cars in front of you, stop signs, or lights? I.e. does it use its sensors to adjust the rate of stopping?

AP or TACC use vision to adjust vehicle speed which includes both Regen and friction brakes. Regen does not use any of those sensors on its own to my knowledge.