Warming battery icon in app

[pt19713]

What’s interesting to note is that if you start to precondition the cabin and it’s cold enough that battery heating icon will show up. Now if you stop the cabin precondition the battery STILL will heat for approximately 20 to 30 minutes before disappearing in the app. I've gotten the front motors to 210F, which is the cap, but that took 30 minutes.

Teslafi will report the vehicle is “charging” and estimated completion will be 30 minutes.... even if you have the charge limit set to 75% and your SOC is 75%. It either is a bug, or the vehicle appears to warm the battery for a set amount of time or to a set point temperature...

Depending how long the pre-conditioning was for, the motors can get quite hot. 15 minutes will get the front motor to signs 190F, the rear will get to around 170F. This will continue to warm the battery for 10-15 minutes.

I've gone grocery shopping, spend 10 minutes in the store, come out and my battery is at the same temp as when I went in because the motors were around 120F (after they dropped from 190F from the pre-conditioning).

 

[acarney]

Depending how long the pre-conditioning was for, the motors can get quite hot. 15 minutes will get the front motor to signs 190F, the rear will get to around 170F. This will continue to warm the battery for 10-15 minutes.

I've gone grocery shopping, spend 10 minutes in the store, come out and my battery is at the same temp as when I went in because the motors were around 120F (after they dropped from 190F from the pre-conditioning).

I preconditioned for maybe a minute, no longer than two minutes.

 

[zannman]

I did a precondition yesterday at around freezing temperature to see the effects. Cabin heated and maximum battery drop by 10-15 minutes per TeslaFi. Car still pulling too much from 30A plug until 45 minutes to restore charge, presumably for stator heaters. I left precondition on and returned to full charge setpoint at approximately 55 minutes.

Unfortunately I didn't check any Battery Temperature readings in ScanMyTesla, but the battery heat icon was gone when turning off Precondition at approximately the 1 hour point. I'm assuming the battery had time to get to setpoint temperature.

 

[acarney]

I did a precondition yesterday at around freezing temperature to see the effects. Cabin heated and maximum battery drop by 10-15 minutes per TeslaFi. Car still pulling too much from 30A plug until 45 minutes to restore charge, presumably for stator heaters. I left precondition on and returned to full charge setpoint at approximately 55 minutes.

Unfortunately I didn't check any Battery Temperature readings in ScanMyTesla, but the battery heat icon was gone when turning off Precondition at approximately the 1 hour point. I'm assuming the battery had time to get to setpoint temperature.

Almost 6kWh is a large amount of energy, I should hope that would be enough to get the cabin and battery up to temperature.

 

[Koolio46]

There are a lot of factors, but an hour of pre-conditioning is a bit overkill for most situations. If temps are around freezing and the car is parked in a garage, 15-20 minutes will be fine. This will use around 2 kW of energy to get the battery temps to around 65-70F. No need to spend 60 minutes and 8 kW to get the batteries to 80-85F. It'll just end up cooling off to 65F.

I precondition for 20-30 mins when my car is in my garage. Seems to heat things up quite well.

If it were outside overnight in the cold, I’d probably do it for 30-45.

 

[rmh9]

I've wondered whether it makes sense to precondition for so long, and what the optimum timing is based on ambient temperature.

As someone who loves one pedal driving, I see the benefit with the regenerative braking, but often wonder whether you use more energy preheating than what you'd get back in a 20-25 minute commute back home in traffic at the end of a work day. I plug the car in every night and use the "scheduled departure" charging method (with preheat on weekdays) so my morning preheat/precondition is straightforward, but my car is unplugged out in the cold all day at work so I have to use the app (or not) before leaving there.

If anyone knows of any article(s) out there that include the actual number crunching, I'd love to know what the optimum solution would be, based on facts rather than my suspicions. Everything I've read from Tesla is vague on this topic.

 

[spokey]

If I'm following, mine doesn't seem to do that. Turned on Climate in the app. The battery and defroster(?) light up. Turn it off and the two turn off in a few seconds. Start/Stop in TeslaFi appear to have the same results. I'm on 2020.48.30 FWIW. My charge is currently set to 79.

I've stopped pre-conditioning except for myself. I was do a 1/2 - 1 hour charge and then right before leaving turning on climate. I had a TeslaFi schedule to set a lower charge at 11:00am (past any normal departure). Plug it in when I get home, then pop the limit up in the morning. I don't use scheduled departure as I don't have a schedule. I have now set heating on for 9:35 on Wednesday to leave at 9:45.

I find the heating piece is quite quick. I think it was 41 inside when I went out tonight and got to 69 in the exactly 5 minutes I gave it (just happened to be testing this out and wanted to see how far it got in 5 minutes).

While I prefer regen, I've also decided that I need more practice with less regen as I plan to not do anything in the snow. I'm thinking full regen is a skid waiting to happen. I might switch to low regen for ice/snow

 

[pt19713]

If I'm following, mine doesn't seem to do that. Turned on Climate in the app. The battery and defroster(?) light up. Turn it off and the two turn off in a few seconds. Start/Stop in TeslaFi appear to have the same results. I'm on 2020.48.30 FWIW. My charge is currently set to 79.

I've stopped pre-conditioning except for myself. I was do a 1/2 - 1 hour charge and then right before leaving turning on climate. I had a TeslaFi schedule to set a lower charge at 11:00am (past any normal departure). Plug it in when I get home, then pop the limit up in the morning. I don't use scheduled departure as I don't have a schedule. I have now set heating on for 9:35 on Wednesday to leave at 9:45.

I find the heating piece is quite quick. I think it was 41 inside when I went out tonight and got to 69 in the exactly 5 minutes I gave it (just happened to be testing this out and wanted to see how far it got in 5 minutes).

While I prefer regen, I've also decided that I need more practice with less regen as I plan to not do anything in the snow. I'm thinking full regen is a skid waiting to happen. I might switch to low regen for ice/snow

15 minutes is sufficient in most temperatures. Even if you have a few dots, ie 6, there's so well over 80% brake regen. The line isn't linear on the display. Most of the time when I still have a few dots, I look in the SMT app and it'll display the actual max brake regen value and I'll still have about 60-65 kW. Max is 78 kW.

 

[SSedan]

Some folks seem to be oblivious that much of the country goes way below freezing.
This winter has been warm sofar but most years Green Bay has seen sub-zero by now as in F not C. Most years I will see -15f at home and have seen -25f a few times.

If the pack chills to 28f it only needs a few degrees to begin getting regen, if the pack falls to low single digits it needs 30degrees of rise.
You live in a place that tickles 30f daily it is a world of difference from areas where we might have a week where we barely reach 10f.

So be more forthcoming with temps you are talking about when you say "10 minutes is enough"

 

[pt19713]

Some folks seem to be oblivious that much of the country goes way below freezing.
This winter has been warm sofar but most years Green Bay has seen sub-zero by now as in F not C. Most years I will see -15f at home and have seen -25f a few times.

If the pack chills to 28f it only needs a few degrees to begin getting regen, if the pack falls to low single digits it needs 30degrees of rise.
You live in a place that tickles 30f daily it is a world of difference from areas where we might have a week where we barely reach 10f.

So be more forthcoming with temps you are talking about when you say "10 minutes is enough"

I say "most temps" because I'm not going to fully detail every temperature and regional difference. There's been numerous posts talking about duration based upon temps and it's a waste of time to repeat the information over and over. People can look at the data and make adjustments accordingly for their own situation. If it takes me 18 minutes in 26F temps, obviously it'll be longer for colder temps. None of us can make that judgement call for you. If you want more precise data for your situation, make a small investment in the datalogging apps and hardware and add your metric data to the community to cover the owners in colder regions.

Are you parked in a garage and if so, what's the temp in the garage?

 

[mswlogo]

I've wondered whether it makes sense to precondition for so long, and what the optimum timing is based on ambient temperature.

As someone who loves one pedal driving, I see the benefit with the regenerative braking, but often wonder whether you use more energy preheating than what you'd get back in a 20-25 minute commute back home in traffic at the end of a work day. I plug the car in every night and use the "scheduled departure" charging method (with preheat on weekdays) so my morning preheat/precondition is straightforward, but my car is unplugged out in the cold all day at work so I have to use the app (or not) before leaving there.

If anyone knows of any article(s) out there that include the actual number crunching, I'd love to know what the optimum solution would be, based on facts rather than my suspicions. Everything I've read from Tesla is vague on this topic.

Well there can’t be a study because it depends on how much regen you have on your commute.

My math says, unless you live on top of a mountain, there is no way in hell you’ll save enough on regen to justify all that heating.

Also keep in mind coasting is the most efficient form of regen. Regen has a charging loss penalty, coasting does not.

So add up all the heat you generated with brakes you used on your commute with no regen. And compare that to 30 minutes of 6kw or more. Which do you think is more energy?

It’s not even close.

 

[pt19713]

Some folks seem to be oblivious that much of the country goes way below freezing.
This winter has been warm sofar but most years Green Bay has seen sub-zero by now as in F not C. Most years I will see -15f at home and have seen -25f a few times.

If the pack chills to 28f it only needs a few degrees to begin getting regen, if the pack falls to low single digits it needs 30degrees of rise.
You live in a place that tickles 30f daily it is a world of difference from areas where we might have a week where we barely reach 10f.

So be more forthcoming with temps you are talking about when you say "10 minutes is enough"

Here's what I've posted a few times in other threads. You can use this info and make adjustments for your situation.

"Cold weather, battery pre-conditioning, 18 minute duration. Warning, lots of nerdy tech stuff below.
I've been logging my data with the Scan My Tesla App and finally got a chance to log info with temps below freezing. The legend doesn't appear to be too legible so if you can't read it, here's what each value is along with some context.

* Outside temperature 26F, temperature inside my garage 47F, as shown in green.
* Front Stator motor started at 62F, shown in blue.
* Rear Stator Motor started at 62F, shown in pink.
* Battery inlet temp started at 51F, shown in red.
* Cell Temp Mid (battery pack) started at 52F, shown in black.

In the first image, you can see the front and rear motors quickly warming up with the front motor being warmer while the vehicle is parked. The highest I've seen the front motor get is 210F. What's happening is the refrigerant is passing by the motors and the heat is picked up via conduction. The Octovalve is then distributing the refrigerant, as needed, so initially some of the heat is sent to the heat pump to warm the cabin, and then routed to the battery pack. As long as the battery inlet temp is greater than the battery pack temp, the battery pack will warm up. The reverse is true, if the inlet temp is lower than the pack temp, the battery will go down in temp.

After 18 minutes:
* Front Stator motor started at 62F, finished at 190F
* Rear Stator Motor started at 62F, finished at 162F
* Battery inlet temp started at 51F, finished at 75F
* Cell Temp Mid (battery pack) started at 52F, finished at 69F
Some notes, observations: Each motor draws 3.5 kW max while pre-conditioning, so the dual motor Y will need 7 kW to pre-condition. With the other things running, such as the heat pump, screen, seat warmers, etc it'll typically be around 7.7 kW while parked and pre-conditioning. You'll need at least a NEMA 14-50 and 32A to keep up with this type of draw. Anything less will pull from the battery and not from the grid."

 

[zannman]

Well there can’t be a study because it depends on how much regen you have on your commute.

My math says, unless you live on top of a mountain, there is no way in hell you’ll save enough on regen to justify all that heating.

Also keep in mind coasting is the most efficient form of regen. Regen has a charging loss penalty, coasting does not.

So add up all the heat you generated with brakes you used on your commute with no regen. And compare that to 30 minutes of 6kw or more. Which do you think is more energy?

It’s not even close.

I don't precondition much. I hope we're not all paying the battery heating penalty to benefit what the heat pump cars need, a reasonable battery temperature to provide cabin heat and some regen. Based on a couple of recent trips, I'm pulling some major KWs early in the trip - way more than cabin heating would need. I don't remember having this behavior last winter, although it's possible the battery didn't have time to cold-soak as much. Perhaps a 2020.48.x change?

 

[jsight]

I don't precondition much. I hope we're not all paying the battery heating penalty to benefit what the heat pump cars need, a reasonable battery temperature to provide cabin heat and some regen. Based on a couple of recent trips, I'm pulling some major KWs early in the trip - way more than cabin heating would need. I don't remember having this behavior last winter, although it's possible the battery didn't have time to cold-soak as much. Perhaps a 2020.48.x change?

The few times that I've had battery preconditioning turn on, it was very noticable. There was a lot of noise as it ramped up in preparation for supercharging and the consumption was at least double the norm.

 

[PagodaY]

I did an experiment today and did not pre-condition my MY before I left. I DO live on the top of a mountain (900' elevation drop to the main road).

Temp was in the low 30s.

When I do precondition for 20 minutes, at the bottom of the mtn I can be as low as - (minus)150wh/m. Today, without pre-conditioning I was about 50wh/m. It made a huge difference. Of course I have to get back up that hill on return home so that will suck up any efficiency advantage, but I consider the fact that I don't have to use brakes a major plus!

 

[tccartier]

It is new to the Y. I've never seen it before now.

Pretty sure it's been there and you just never had occasion for it to be on. Remember it's not the ambient temperature it is the core temperature of the battery pack which is a pretty large thermal Mass roughly a thousand pounds or more so it doesn't change temperature significantly within a matter of a few hours just because the ambient temperature changes. My battery heater icon came on today when I turned on climate to precondition.