Cold battery / regen question (issue?)

[Benito1283]

I left for some errands this morning after a very cold night (15F). Cold car - no charging or preconditioning first. I didn’t have any regen, which I expected at first. Instead of green regen line, it went right to gray line and I felt the brake click engage - terrific feature by the way. All fine.

Typically as a keep driving I pretty quickly gain some regen and increases as I continue to drive. I drove for 15 minutes and when I reached my first destination I still had zero regen (immediate break engagement). I parked, went in a store to pick something up, and when I came out I had about 50% regen capacity (dots went halfway from left to middle).

I feel like this is a bug unless there’s something I don’t understand. There’s no way the battery temp suddenly increased when I was in the store. Regen should be added gradually as the battery warms from driving. My energy graph confirm there was no regen on that first drive - no green. Thoughts?

 

[ZenRockGarden]

Usually no-regen is under full-battery conditions (and shows an alert on the screen).

I've never seen it in the cold, but then again I live in a mild climate.

For regen to work, the battery has to be able to absorb the amount of regen energy being generated.

 

[Benito1283]

Usually no-regen is under full-battery conditions (and shows an alert on the screen).

I've never seen it in the cold, but then again I live in a mild climate.

For regen to work, the battery has to be able to absorb the amount of regen energy being generated.

Regen is limited when the battery is cold as well as full. But I did think that absolutely zero regen was a little weird. It wasn’t subzero or anything.

 

[Benito1283]

During the final leg of my errands, my regen gradually increased as I drove, as expected. PS started the whole trip with 65% battery. My hunch is that ZERO regen for the entire first drive was some type of glitch.

 

[Sophias_dad]

FYI, there's apparently(now) a setting so the car will emulate regenerative braking using brakes when the battery is cold.

But yeah, you gotta drive the car pretty hard to warm up the battery. I've been 25 highway miles away from home and still had to beat on it a bit to get full regen braking. A couple errands around town don't have a chance.

 

[Benito1283]

FYI, there's apparently(now) a setting so the car will emulate regenerative braking using brakes when the battery is cold.

But yeah, you gotta drive the car pretty hard to warm up the battery. I've been 25 highway miles away from home and still had to beat on it a bit to get full regen braking. A couple errands around town don't have a chance.

Yep, it’s a fantastic feature and I have it enabled. But I’m referring to absolutely zero regen, totally disabled, then went in a store for two minutes, then 50% regen available immediately on next drive.

 

[Pianewman]

While driving, battery is struggling to increase heat. Stopping after 15 minutes, whatever heat was generated probably spikes after the cold air is stopped rushing around it.

Just a WAG...

 

[240vPlug]

Parked outside overnight in 15F no Regen sounds about right. Even parked in a non heated garage I can only get about 25-50% Regen until I have driven for a good while. If you had the heat on the battery may have warmed up some during your first stop.

 

[GtiMart]

I feel like this is a bug unless there’s something I don’t understand. There’s no way the battery temp suddenly increased when I was in the store.

Yes there is . While you drove, the motors/stators got warmer. That heat is circulated in the battery. The battery is a big mass, it takes a long time to change temperature. When you went inside, the car continued to circulate the glycol, extracting the remaining heat from thors motors/stators and putting it into the battery. The battery continued to heat up without the car spending extra energy in heat. You car does not fall to sleep immediately, it continues to run exactly for this type of thing.

 

[MajorTom]

Yep, it’s a fantastic feature and I have it enabled. But I’m referring to absolutely zero regen, totally disabled, then went in a store for two minutes, then 50% regen available immediately on next drive.

My new Y is doing the same thing. Happened today. Stopped just like you in time to buy a soda and was greeted by regen. My 2020 3 never did this - I would always have some, even if the smallest amount and you could watch it regain dots.

 

[thesmokingman]

I feel like this is a bug unless there’s something I don’t understand. There’s no way the battery temp suddenly increased when I was in the store. Regen should be added gradually as the battery warms from driving. My energy graph confirm there was no regen on that first drive - no green. Thoughts?

 

[ZenRockGarden]

It's like people discovered physics that electrons move slowly in frozen temps or something...

 

[GtiMart]

My 2020 lr awd seems to do this as well now: no regen for a while then all of a sudden, half regen. Must be a software update that changed how regen comes on...

 

[rrrvan]

I never get full regen braking. Always dots. I have tried preconditioning 30-45 minutes in advance and still can't get full regen. I charge up to 80% and the outside temperature is 10-15C which is about 50-60 F. The most I've seen lately has been 3 quarter full regen even when batter is down to 60%. Should I be concerned?

 

[240vPlug]

I never get full regen braking. Always dots. I have tried preconditioning 30-45 minutes in advance and still can't get full regen. I charge up to 80% and the outside temperature is 10-15C which is about 50-60 F. The most I've seen lately has been 3 quarter full regen even when batter is down to 60%. Should I be concerned?

I see your in Vancouver. Sustained temps need to be warmer. Regen will improve as we get into the spring and summer months.

 

[jcanoe]

I never get full regen braking. Always dots. I have tried preconditioning 30-45 minutes in advance and still can't get full regen. I charge up to 80% and the outside temperature is 10-15C which is about 50-60 F. The most I've seen lately has been 3 quarter full regen even when batter is down to 60%. Should I be concerned?

When preconditioning the Tesla Model Y will only warm the battery to 4.5C (40F) as needed for charging but not to 21C 70F) that would be needed for full regenerative braking. Preconditioning for long periods just uses more energy. In most cases you can precondition for 10 minutes or less and the passenger cabin will be fully warmed.

Under Pedals and Driving you can now enable blended friction braking for those times when regenerative braking is reduced or unavailable. You can observe the level of regenerative braking available. The Tesla Model Y will display the regenerative braking being applied in green on the power bar, any friction braking being applied will be displayed in grey. When blended friction braking is enabled the Tesla Model slows as expected when you lift your foot from the accelerator, no surprise when regenerative braking is reduced or unavailable.