You're saying you want the car to keep the battery warm enough to absorb full regen **all the time**? If you're parked in a cold garage for any length of time this is going to be a decidedly non-trivial amount of energy used to keep the pack warm. I have doubts that most people would want to use that much electricity consistently....
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You're saying you want the car to keep the battery warm enough to absorb full regen **all the time**? If you're parked in a cold garage for any length of time this is going to be a decidedly non-trivial amount of energy used to keep the pack warm. I have doubts that most people would want to use that much electricity consistently....
So, a question relevant to what happens when you actually start moving. I've see the heating and cooling graphic around the forums and always wondered if the heat created from the motor can keep the battery warm DURING driving. Can anyone confirm that? Preheating sounds like a great idea to condition the battery for the charge. What happens during the long drive?
ThosEM
Space Weatherman
There is the option to unplug the car, which I noted. But a user selectable option in software would be nice I agree, especially if needing to correct the option remotely.
huntjo
Member
you're basically asking for the worst Vampire drain ever, which is what we had for the first month of ownership. My car charged to 90% at the airport, then the public charger automatically turned off since it was "done". Then 7 days of freezing weather (lots of which was sub zero Farenheit) took my battery to like 20% SOC just by keeping its systems running and warming itself. They changed the threshold to allow the battery to get colder when not in use (since it doesn't harm the battery to be a little cold) and then heat up once you start (to take advantage of some waste heat anyways).
Nowadays, you Tesla young'n's take your energy conserving systems for granted. Especially with your newfangled "apps" with the phones that can wake up the car and preheat it before you get there so the battery is heated a bit as well. If you want the car closer to full regen etc, just keep "range mode" off for your HVAC systems, and "energy saving mode" off for your displays. As mentioned above, keep it plugged in and schedule it to complete the charge around the time you want to leave (btw we also did not have scheduled charging for a couple months- that was a software update). For icing on the cake, you can preheat the car 15 mins before leaving as well.
In recent software versions, it draws power from the wall. (This will probably reduce the rate at which the battery is charging, unless you're at a very high-powered charger.) Since I don't use the app, I've taken to just propping the door of my car open for an hour before heading out. I can't do that if I'm not at home, obviously.
Charging shortly before leaving eliminates the rather annoying "Battery is warming" bleeping messages which I normally get on every single drive anywhere. I need to complain to Tesla that this is not the sort of thing which should show up as an alert -- I've taken to ignoring it and as a result I'll probably ignore any ACTUAL warnings about ACTUAL problems with the car.
...time to phone Tesla and watch my bug reports sink into the black hole which is Tesla's non-responsive software team.
Can you rephrase? My understanding is that while plugged in the car won't ever be in drive, as such "regen" will never be in play.
LOL I spend most of the winter without full regen available.
Preheating doesn't seem to get the pack much above 30 kW regen levels, no matter how long you preheat it. You need to actually drive for a while at highway speeds to get full regen back.
Right. If it's below about -8C the regen limit line will be around 30 kW. Above that and two preheat sessions does get rid of the line--assuming you are not in range mode. They really need to fix that so that when plugged in it's never in range mode.
Note that's when parked outside.
This is the common believe, and in fact what the Ownership hotline says, however, this apparently is not true. I have had very specific conversations with my local SC Manager on this matter given that I saw no demonstrable benefit to 'pre-heating' the car as it pertained to the battery and regen. Below is a direct quote from my local SC manager pertaining to this issue:
"Yes, pre-warming is still advisable as it prevents the large loss of range and the additional heat may provide a little, barely noticeable effect on the regen, so the cold weather routine is still best, but the regen benefit is not accurate as it s [sic] more about the battery retaining proper operating temperature thus increased range. I will read through the forums though as it sounds like there is a lot of pertinent information out there!"
This was in response to my suggesting that the pre-warm routine as it pertains to the battery is really useless. The pre-warm does cut down on battery usage, but only to the effect of reducing the initial energy required to bring the cabin up to temp - but has no impact on the battery warming up. Earlier in the email conversation, he explained why using the iPhone app to pre-warm the cabin has no impact on the battery and regen:
"For the Tesla, because the coolant actually travels through the drive motor and so forth, operating the car gets all the components up to temp. I will make sure I am standing alone correct on this, but every experienced manager (also with technician backgrounds) I have talked to in the last hour or so has confirmed what I am saying. I am waiting for something in writing from Cali as we “speak”!"
What he is referring to is that for the battery to come up to proper temp, the car has to be operated, specifically when referring to my question of "So that means, there is effectively NO WAY to ensure the battery is properly 'warmed up' such that in cold temperatures, the car will be able to be driven immediately without regen limitation", his response was:
"Not exactly, the battery warms up effectively, but regen limitation is completely normal to a varying period of time regardless depending on the ambient conditions. My best traditional internal combustion comparison to this is that I warm up my truck when it is freezing out for about 20 minutes, it certainly helps and the truck is warm, but there is still a brief period of time where things aren’t quite as warm as they are after driving it for a minute….Not sure if the last part helps, but delayed regen is normal despite the pre-warm scenarios."
So in a nutshell, while it is advisable to pre-heat the cabin to reduce if not eliminate the initial power consumption required to bring the cabin up to temp, it has very little, if any impact on the battery.
ThosEM
Space Weatherman
Not sure about others, but for me, I don't really care whether I have regen. or not as I head out on a cold day. If it is icy/slippery, it's actually helpful NOT to have regen working very much since it can break loose the back of the car just by taking ones foot off the accelerator.
My concern is with what happens when the "Battery is warming" warning comes on, which can easily be 10-15 km of very high power consumption totaling 5-6 kWh of power, until the thermostat is satisfied with the battery temperature. That reliably comes when the regen limit rises to 30 kW in my car, which can take a while, as I've noted.
I'm really pretty upset that there does not seem to be a definitive and reliable way to do that warming on shore power when it is available, even though we were admonished that "A plugged in Tesla is a happy Tesla" when we took delivery of the Model S. I've written my DS asking that shore power warming (or cooling in hot weather) be made the default unless it is deactivated by owners who don't want to spend the energy on it, OR that scheduled charging should get an option for "Complete charging by HH:MM hrs" (departure time), if it truly requires charging to be underway.
There's are related suggested features for that on Teslatap, and I hope those concerned will go there and vote them up:
Battery and Charging | TeslaTap
My concern is with what happens when the "Battery is warming" warning comes on, which can easily be 10-15 km of very high power consumption totaling 5-6 kWh of power, until the thermostat is satisfied with the battery temperature. That reliably comes when the regen limit rises to 30 kW in my car, which can take a while, as I've noted.
I'm really pretty upset that there does not seem to be a definitive and reliable way to do that warming on shore power when it is available, even though we were admonished that "A plugged in Tesla is a happy Tesla" when we took delivery of the Model S. I've written my DS asking that shore power warming (or cooling in hot weather) be made the default unless it is deactivated by owners who don't want to spend the energy on it, OR that scheduled charging should get an option for "Complete charging by HH:MM hrs" (departure time), if it truly requires charging to be underway.
There's are related suggested features for that on Teslatap, and I hope those concerned will go there and vote them up:
Battery and Charging | TeslaTap
I agree with most of this. Furthermore, there should be a means to 'warm up' the battery fully when its plugged in. In addition, the ability to turn on/off Range Mode from the phone app should be available as this does impact cabin warming.
That said, i think having full regen is important, as wh/mi average is really dependent on regen, and so if you don't have it, one will inevitably not get the rated mileage or efficiency - don't forget you can always turn off standard regen in favor of very little regen.
The problem with this hypothesis is that it doesn't match the observations:
A comparison of two days last winter
Common data for both days:
Temperature: -8 C
Parked: Outside
Charging from 02:30-05:15
Range gained: 55 miles
Charging amps: 32
Range mode: off
Energy saver mode: on
Day with no pre-heating:
Power limiting about 300 kW
Regen limited to less than 15 kW
When starting to drive battery is heating message is on
Day with two pre-heating cycles:
No power limiting
Regen limited to about 30 Kw
The conclusions that might be drawn:
1. The instrumentation is badly broken.
2. The hypothesis is incorrect. (To be fair, it probably is correct in Southern California where cold never happens.)
The general manager at the local service centre said that my lights were adjust perfectly every time I complained about how low they were set. After three tries to get them adjusted right (and each time the GM said there was no need to adjust because they were correct), someone from the factory came and and got them aligned correctly (and showed the staff how to set the headlights). The tire alignment was also "perfect" according to the general manager, but the tires said otherwise (both front and rear). Sorry, but I'm going with the observations.
ThosEM
Space Weatherman
Furthermore? That was the main point of my post.
But I took it further:
That is, battery thermal conditioning should BY DEFAULT be automatic while plugged in, unless the owner chooses otherwise.
Isn't that implicit in the idea that "A plugged in Tesla is a happy Tesla"?
That would necessarily take care of enabling regen in cold weather, at least when departing from shore power.
My 2¢...
This may be from a service manager, but it is simply WRONG. I do this daily all winter. If I fully preheat I get half regen. If I don't reheat I get ZERO regen. Regen clearly benefits significantly.
It most certainly DOES warm up the battery. Impact on regen is obvious. Impact on Wh/km is even more obvious, i.e. factor of two difference in extreme cold.
That is correct. You will not get 100% regen after full preheating. Getting 100% regen requires driving the car. However preheating does give you 30 kW regen or 50%, which is a LOT better than zero.
As I have already demonstrated, this is false. I have empirical evidence that is clearly to the contrary. And this is my second winter, so I have plenty of empirical evidence.
However, simply plugging in the car is not sufficient. It must be either actively charging or the cabin preheat has to be activated via the remote app. Those two methods are the only way to engage the pack heater while the car is stationary.
LXAwolf said:
Hi LXAwolf - for some reason you "reported" my post instead of replying to it. However since I'm a moderator (though not in this section) I saw it anyway.
The simple answer is, "no". I do not have the cold weather package. That package was not offered until nearly a year after my Model S was delivered.
The cold weather package adds heated wipers, heated rear seats, and an upgraded defroster grille. Tesla Service installed the upgraded grilles in all the early Canadian cars. I don't have any other features of the package.
I'm pretty sure the battery pack heater behavior is the same for all cars. Especially since Tesla promoted the pack preheating as one of the key features of the Remote App.
I've owned Tesla vehicles since 2010, and I learned early on that you can't always depend on what employees tell you about how the car works - even senior people. It's not that they would deliberately mislead you; it's just that they don't always fully understand all of the myriad details of the car's engineering. It's a pretty complex machine.
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