Yeah, the no heat while the preheating message is on is more of what I am looking at at least in the past. In the past that could be explained by the car not being able to add heat via the rear stator while at speed. Now that seems to have changed somehow which is what I am investigating in the other thread.
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Longer to charge at home in colder weather?
- Thread starter metroplex
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Yeah, the no heat while the preheating message is on is more of what I am looking at at least in the past. In the past that could be explained by the car not being able to add heat via the rear stator while at speed. Now that seems to have changed somehow which is what I am investigating in the other thread.
I believe the message will appear as soon as the car actively spends extra energy in the stators to generate heat that it sends to the battery. IF you touch the message it disappears but that does NOT stop the car from doing it, it just gives you back that screen real estate.
I *think* that the car can adjust valves and what not to send more heat to the battery without actively generating extra heat through the stators. I think this is what @derotam is seeing.
I *think* that the car can adjust valves and what not to send more heat to the battery without actively generating extra heat through the stators. I think this is what @derotam is seeing.
You have to get the heat from somewhere though, what in the vehicle can generate and transfer the amount of heat required? In a 2018 RWD, the only thing is the stator. In newer vehicles, maybe the heat pump but only in temps where it wouldn't really be required. Get into 20F temps and that heat pump isn't going to do much.
With a stator temp of 20-30C and a battery temp of 16C and limited regen due to cold battery it isn't going to send any heat to the radiator.
So my energy data finally updated (for my utility company). It looks like 2.2 kWh was used initially to heat the battery, because the total charge was 9.4 kWh and that didn't make sense to me since I only used about 7.2 kWh for driving. So the first 45 minutes I had a charge estimate of about 4.5 hours and right after this ~45 minutes, the estimate went back to what I'd expect at about 2.5 hours. Ambient temperatures weren't that cold either. It can dip down to -10F or so in SE MI during winter with wind chills even lower than that. We rarely go over single digits (F) during winter.
10C on the battery is not close to full regen, more like close to no regen.
Well check ScanMyTesla again @derotam. Two years ago you would have been right. LAst year they adjusted those values quite a bit. From memory, active heat was just at 7C and residual heat would get to around 10C, at which point I saw a good 50kW of regen out of a total of 85kW. To me that is good regen. I'll check again soon, now that the cold is upon us.
I did before I made my comment. This morning my battery was at 14C and I had severely restricted regen. I do not remember what the regen amount was but I had at least 10 dots of limited regen on the power bar. I am still trying to figure out recording data in SMT as I think they took out the native recording ability.
Please watch your terminology. "Active Heat" to me would be a point where the car starts actively heating the battery in order to avoid damage. Back in 2018/2019 in SMT it showed the car reporting that value to be -7C. Unfortunately while I was testing the temperature in my area never got cold enough for me to check the actual operation of that.
As I am doing now, you might want to avoid going "from memory" and retest everything before making additional comments.
The active heat temperature I stated comes from SMT, and that value changes depending on various conditions. It will be higher when navigating to a SC I believe. I am pretty sure it's used when conditioning in the morning too.
I park in a heated garage and my battery is around 11-12C in the mornings. I have no regen dots when I leave in the morning and I believe max regen in SMT is 85kW (but I will double-check soon)
Yes, I will start looking at SMT again and take new notes this winter.
Do you have one of the new LFP batteries?
I park in a heated garage and my battery is around 11-12C in the mornings. I have no regen dots when I leave in the morning and I believe max regen in SMT is 85kW (but I will double-check soon)
Yes, I will start looking at SMT again and take new notes this winter.
Do you have one of the new LFP batteries?
Nope all my data is concerning a 2018 Model 3 LR RWD and I usually make that statement when I put out data. I am fully aware that things could be different with different chemistries so it is always good to reference the tested vehicle configuration when reporting data.
If you haven't been looking at SMT data then how do you know your battery has been at 11-12C in the mornings or are you making that statement from memory as well?
Damn man you are being rough... Can we just try to help each other?
I do check SMT from time to time, I just don't start it on every drive. I remember a morning this week or last where I did check. I made a note about double-checking specifically because you were dismissing my memory and requested I check again.
I do check SMT from time to time, I just don't start it on every drive. I remember a morning this week or last where I did check. I made a note about double-checking specifically because you were dismissing my memory and requested I check again.
Not trying to be rough or mean. One of your past statements made it sound like you haven't been looking at SMT for a while, that's all.
I am all about helping each other out, I just want to have the data to analyze to be able to more completely figure out what happens when and under what conditions. I had it all figured out in 2018/19 but it's all changed now even on my 2018 LR RWD. Now I just have to figure out how to get SMT to write a log file again.
I gathered some data while going out for lunch today. Here's SMT as I stepped in the car:
Battery at 7.5-8C, 59.5kW of regen, and no regen dots on the bar. Outside temp -1C, battery SOC 50%. As I drove the max regen value would go up while accelerating and back down as I used regen to slow down. I saw it go up to 69kW at one point with the same battery temp. I only drove for 2km.
As I got back in the car ~30 min later to come back to the office, my SOC was now at 48% and at that point the blue snowflake had appeared. SMT was now showing:
0C outside temp. Still not dots on the regen bar.
My car is a 2020 LR AWD model 3. I'm running 2022.40.4.
Battery at 7.5-8C, 59.5kW of regen, and no regen dots on the bar. Outside temp -1C, battery SOC 50%. As I drove the max regen value would go up while accelerating and back down as I used regen to slow down. I saw it go up to 69kW at one point with the same battery temp. I only drove for 2km.
As I got back in the car ~30 min later to come back to the office, my SOC was now at 48% and at that point the blue snowflake had appeared. SMT was now showing:
0C outside temp. Still not dots on the regen bar.
My car is a 2020 LR AWD model 3. I'm running 2022.40.4.
The algorithm that controls regen is based on much more than just temperature. I took the car up a mountain on a warm day (warm enough that I had to have the AC running and was wearing a T-shirt and shorts when outside of the car) and I saw regen get limited on the way down. Seems it will only let you push a certain amount of energy into the battery in a short period of time before it lowers the peak; I saw the dotted line appear on the regen portion of the power bar while coming down the mountain, after I had been descending a steep hill for a long enough time and using regen all the way down. And yes, once it hit that limit, it refused to do any more and I had to use the friction brakes.
Yes, absolutely, it is not only temperature. I just explained what happened to me at lunch where I had partial regen (because of temperature) but it would go up when I accelerated and down when I used regen without the battery temp changing at all. That also applies when warm as you indicate.
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