2019.32.1 - New bug or old one (or just my S being weird)

[Gaz_]

So here is my weird one.

1. Update to 2019.32.1
2. Charge overnight to 100% because its 180 miles to the supercharger
3. Leave home with 100% charge and the usual limited regen because the battery is full
4. Get to first stop last night at about 60% charge (I've not reset the charge limit but I'm not charging either)
5. Get in the car this morning to find that I have limited regen again for the first 10 miles

I think the bug is that if you don't change the charge limit down from 100% then when you get in and drive you don't have full regen even when the battery isn't full.

Is this just my S being weird or has anyone else experienced limited regen even when their is battery capacity?

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[Shateam]

What was the ambient temperature at your location this morning?

Regenerative braking will be limited if its too (cold) cool outside until the pack has a chance to warm up a bit. The colder the battery pack, the more yellow dotted lines you'll see on the instrument cluster.

 

[Gaz_]

A completely reasonable 15C, It's never done it at 10C or so degrees, this is the first time

 

[quickstrike12]

Do you have range mode on or off? I believe it sets the allowable batt temp ranges a bit different. Could have been just cool enough for it to limit the regen by small amount.
If a “bug” we’re going to limit Regen due to a set point thinking it was at 100% I would think it would limit regen completely not partially for a short time.

Just a thought.
Another thought is 59f temps maybe the reported but a good wind will make the battery colder than that easily when when parked outside.

 

[VT_EE]

There are a lot of adjustments happening with the BMS including on my Model 3 (based on my observations in my vehicle and reading this forum). I doubt limited regen for a short period in the morning is anything you need to worry about as long as everything else is working fine. I wish Tesla would include information on these changes in release notes so customers won't freak out.

 

[ckoval7]

What was the low temperature overnight? The car starts limiting regen when the battery temperature is around 55F (12.7C). The battery is likely to be closer to the low overnight temp first thing in the morning because it has a lot of mass to warm up.

 

[jerry33]

A completely reasonable 15C, It's never done it at 10C or so degrees, this is the first time

Was 15C the low of the night or just the temperature when you started to drive?

 

[Dithermaster]

The battery is likely to be closer to the low overnight temp first thing in the morning because it has a lot of mass to warm up.

This. I'm from the midwest and can confirm that temperature-limited regen can happen even when the "right now" ambient is quite nice (if it was colder overnight).

 

[Gaz_]

I guess it could be, but first week of September in the west end of London is rarely that chilly I'd have to check the overnight weather somewhere. I'd still consider this "Summer nights", I left the house windows open.

Update: According to the Met Office the low overnight (6am) was 7C but was 14C when I got in the car (11am). So this could be the case, but seems like that should be normal operating temps to me?

 

[jdw]

Tesla has moved to being much more conservative with regen limits over the past few years. It used to introduce limited regen around 8-10C (45-50F) ambient temps, now it seems to start just below 15C (60F). Likely due to increased evidence of lithium plating in the batteries when charging at low temperatures.

 

[jerry33]

I guess it could be, but first week of September in the west end of London is rarely that chilly I'd have to check the overnight weather somewhere. I'd still consider this "Summer nights", I left the house windows open.

Update: According to the Met Office the low overnight (6am) was 7C but was 14C when I got in the car (11am). So this could be the case, but seems like that should be normal operating temps to me?

The battery pack has a large thermal mass.