Regen limitation in cold weather

[PhilBa]

Has anyone seen the "Warming Battery" alert? It popped up under the speedometer/wattometer. I did a number of searches and didn't see it. It seems like people are seeing colder temps than I but not the alert. Wish I'd taken a picture of it.

I'm still on 4.5, btw.

 

[jerry33]

Has anyone seen the "Warming Battery" alert? It popped up under the speedometer/wattometer. I did a number of searches and didn't see it. It seems like people are seeing colder temps than I but not the alert. Wish I'd taken a picture of it.

If you have your charging set so that it ends shortly before you drive, you won't see the alert.

 

[PhilBa]

yeah, that would be nice but in this case I don't have access to a charger at that location.

 

[cinergi]

The regen limiting is a lot more aggressive on the newer firmware versions than it was last year. I also have been seeing it last a bit longer while driving before it drops the limit.
I haven't had the 'battery warming' yet this season but was limited quite low the other morning since I hadn't charged and it was ~ 36F when I left for work

Agreed.

 

[mknox]

The regen limiting is a lot more aggressive on the newer firmware versions than it was last year. I also have been seeing it last a bit longer while driving before it drops the limit.
I haven't had the 'battery warming' yet this season but was limited quite low the other morning since I hadn't charged and it was ~ 36F when I left for work

Same here.

 

[Denarius]

Has anyone seen the "Warming Battery" alert? It popped up under the speedometer/wattometer. I did a number of searches and didn't see it. It seems like people are seeing colder temps than I but not the alert. Wish I'd taken a picture of it.

I'm still on 4.5, btw.

That or preheat the cabin.

 

[mknox]

Noticed something else this morning. It was "cool" but not "cold" and I had no regen limit showing on the dash. Nonetheless, I was only getting about 30 kW max of regen when I first set out. It eventually got up to about 45 and after 10 or 15 miles I was able to get the full 60.

EDIT: I started out at about 70% SOC.

 

[scaesare]

Noticed something else this morning. It was "cool" but not "cold" and I had no regen limit showing on the dash. Nonetheless, I was only getting about 30 kW max of regen when I first set out. It eventually got up to about 45 and after 10 or 15 miles I was able to get the full 60.

EDIT: I started out at about 70% SOC.

Interesting.

I've noticed that the dashed "limit-lines" for both regen and max power usage will go away after a while, and then sometime reappear, only to go away again. I assumed it was because the pack temp was right at the threshold of being "warm enough".

However, on a couple of occasions when I went to accelerate (or regen), it appeared I WAS limited still, despite the limit-line being gone. In a couple of instances as the power-usage "needle" swept up the dashed-line appeared "within" the needle-sweep shaded area... as if the acceleration attempt "revealed" where the limit should have been displaying.

All of that to say that in temps where we are on the edge of the threshold for limiting, I think there may be some display/latency anomalies on occasion... once I drive a bit longer and things warm up more, they go away...

 

[cinergi]

The regen limit indicator (the dashed yellow lines) disappears around 45-50 or so ... but regen is still limited, yes. It's unfortunately been this way since day 1. Wouldn't hurt to ask ownership to fix that ... "vote" with an email!

 

[Aphysician]

I had my first experience with regen limiting today, or may be the first that I noticed. I have seen the line few times but didn't know what that meant and it was always at sufficient KW range so didn't notice any change in driving behavior. It suddenly got very cold in Michigan today. Temp was around 15 F, don't know what was it with wind chill. Car was parked for 10 hours. I had no idea regen limiting happens, so drove normally and then realized the change. Thought I might have changed it to low regen, nope not the case. Then I saw the yellow triangle, regen failed. Was scared till I came back and started browsing TMC. I drove for 10 miles or so, but regen never came back. It is scary and dangerous that car behavior changes so much and this suddenly, esp for an unsuspecting driver like me. Tesla needs to educate about this phenomenon. I don't know whether regen limit behavior has been changed in latest release? I upgraded the software as soon as it came out. Good thing is now I know what to expect in frigid conditions. I don't think so it will get any worse than this in winter (Temp wise). I have 60 kWh, and I think not having regen will be a big factor for folks with 60 kWh. There will be significant range limitation. I hit 420 kWh in my commute, which is usually 320 kWh.

 

[jerry33]

I had my first experience with regen limiting today, or may be the first that I noticed. I have seen the line few times but didn't know what that meant and it was always at sufficient KW range so didn't notice any change in driving behavior. It suddenly got very cold in Michigan today.

The trick is to set your charging so that it ends about the time you leave. What I do is set it for lower than normal and then start charging the rest of the way as soon as I wake up. About 30 minutes before leaving I turn the pre-heating on as well.

 

[Daniel Scherer]

Max range in cold weather.

Preheat your car 20 minutes before you unplug this uses house power and not battery. Drive easy by watching your kW usage. Try not to exceed 30kW on acceleration. Once up to speed, keep it at or below 20 kW on your dash screen. Turn your power screen on you center panel and set it to 5 mile average and try to get below 333wH. This may only get you to about 60mph on the highway but you will get 3 miles per 1kW. I drop in behind trucks doing 63mph and draft them. This also keeps people from getting mad at you for going so slow. If you get into slippery conditions set your regen to light or you will back pedal your rear tires and may spin out. Use your seat heaters as they use less power. I don't have a sun roof so fogging is a problem. I run my fan on 3, set too defrost and open the passenger side rear window a crack just to circulate air.

 

[brianman]

Try not to exceed 30kW on acceleration.

Note that the gauges are not linear, so that is not the mid-point between 20 kW and 40 kW. FYI.

 

[Aphysician]

@ jerry33, @dan scherer, @brianman

Thank you for your suggestions. I had noticed lately that my energy use was through the roof. I had noticed that car was using a lot of energy when I start it. I think it was a combination to heat the battery and low regen in cold condition. My commute is on shorter side so I can afford to charge every third day, and I thought what was the need to plug the car if I don't need the range. Now I realize that if I would have kept it plugged in then battery would have been kept warm using home power.

Scheduling charging to end just before I leave could be the solution. Stopping charging at lower range and then top off remaining range in morning is a great idea or I can roughly calculate how much charge I will need and just start charging late for that day. This will solve the problem from home to work. I don't have workplace charging and will have to deal with this problem on my way back.

Dan those are excellent suggestions. You must be a pro at it now after your long commutes last winter. I haven't taken out mine on the highway lately and just using local roads to commute. The overall energy use has been creeping up due to Stop-N-Go nature of city commute and my jack rabbit behavior between lights. One important point you made was to set regen to low in slippery condition.

 

[jerry33]

This will solve the problem from home to work. I don't have workplace charging and will have to deal with this problem on my way back.

Even in Michigan it's likely to be warmer when you leave from work than when you leave from home, so some of the difference will be mitigated.

 

[Daniel Scherer]

Note that the gauges are not linear, so that is not the mid-point between 20 kW and 40 kW. FYI.

I was not aware of this but still good to know. Thanks

 

[jerry33]

I was not aware of this but still good to know. Thanks

My understanding is that the midpoint is the slightly heavy dot just below the heavy dot with the number beside it (It's logarithmic).

 

[J in MN]

Even in Michigan it's likely to be warmer when you leave from work than when you leave from home, so some of the difference will be mitigated.

The opposite is true for me. The protection provided by a garage and the heat generated from charging always means a warmer battery and hence more regen in the morning than in the evening after the car has been parked outside all day.

 

[montgom626]

The opposite is true for me. The protection provided by a garage and the heat generated from charging always means a warmer battery and hence more regen in the morning than in the evening after the car has been parked outside all day.

Same here. Except when the outside temp goes from 20 to 40F. I think that is what Jerry33 meant.

 

[Aphysician]

@J in MN, @montgom26

Same here. Battery is warmer in morning as car in the garage. I have long hours at work, and gets cold before I head back home. Jerry is also right as afternoon temp is usually higher than frigid overnight conditions. I think suggestion to end charge just before leaving is the most practical one. I tried it for couple of days and energy use is coming down.