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First Winter with my S: battery questions

First Winter with my S: battery questions

I purchased a model S in the spring and am heading into my first winter with the car and trying to understand how cold temps affect range and battery.

We had a cold night in the teens last night. I got in the car this morning showing 97 miles of range, drove one mile to go shopping and the car showed 92 miles of range. I shopped for an hour and the car showed 88 miles of range. I drove one mile back home and went back out 3 hours later and the car showed 80 miles of range. The 30 mile average was showing ~450wh/mi. Temps were around 30.

Again, i am a winter Tesla newbie, so perhaps this is normal. Basically, i am trying to figure things out and set expectations as far as range in colder temps.

Does the above seem normal?

Should i be expecting to lose 5mi every time i stop the car for a bit, and another 10+ each cold night?

Bighorn | 12 décembre 2019

In the winter, I plug in at night and keep a higher SOC than in the summer. Scheduling the charge to happen right upon morning departure will help warm the battery. A cold soaked battery uses a lot of energy to heat itself. Garages are very helpful if it keeps the battery from assuming outdoor temps.

nbrianjohnston | 12 décembre 2019

Perfectly normal. Cold weather usually decreases available range in the pack by +/- 20%. Preconditioning the car, to warm the battery a bit before you leave helps, but in winter you will use more energy because the battery has to be kept warm. You may also be running your heat, headlights, windshield wipers, rear defrost, etc.

garyjtate | 12 décembre 2019

Plug it in.....

AERODYNE | 12 décembre 2019

Colder temps also mean the air is more dense, increasing air drag.

Having an app like teslafi will show you if your range is limited by cold. You will see a lower battery percentage in blue text.

When it warms up, you will regain a percentage point or two, less phantom drain....

Anthony J. Parisio | 13 décembre 2019

I always assume the car will go 1/3 less range than is says in the winter. This has been a safe estimate for me over the past 5 years. I have found what others have written in this post to be very true.

greg | 13 décembre 2019

Very helpful replies, thanks all.

Two follow-up questions:
1. Several people have mentioned plugging in the car at night/keeping it plugged in. This would seem to break the "For maximum battery longevity, Start charging charge at 20% and charge to 80%" rule if my car already had a high state of charge. So lets say its a cold day and I'm at 70%. Should i be plugging the car back in to keep the battery from having a reduced charge from cold?

2. Is there a way to make the car pre-condition/heat the battery while its still in my garage before i leave and drive in the cold? Would doing so help reduce loss of range?

jimglas | 13 décembre 2019

keep your car plugged in
1/2 hr before your leave, preheat the interior and seat and charge your car for 15 minutes to warm the battery
At least that's what I do.

Bighorn | 13 décembre 2019

Start charging at 20 is not a thing. Replenish your losses every day, ideally scheduled to happen before departure.
Using the app to turn on climate before departure will preheat the battery as well. You mitigate range loss by being plugged in.

reed_lewis | 13 décembre 2019

...A plugged in Tesla is a happy Tesla.

A Li-Ion battery is not like a Ni-CD or Ni-Mh battery. You want to plug it in every time you can.

As to your trips, the first few miles when the car is very cold will use a LOT of power. As the car warms up, it will use less. The best thing is to pre-heat it for about 30-45 minutes before you depart and you will get better range. But if your trips are short, then do not worry about it. Just plug it in whenever you can.

Reds Tesla | 13 décembre 2019

Have a new S in Boston and would say I lose 40% on cold days with short trips. Disappointing but this is the reality. An ICE car driven 5-10 miles in the cold gets TERRIBLE milage as well. We can't beat physics, but Tesla does a terrible job being honest about this issue.

A few tricks I believe are true:

1. Tesla technician told me

a. turn off the wake for summon (autopilot menu) feature if I'm not going to use it. Keeps the car in a more "active" state that will cause more
phantom drain at night.
b. Turn off cabin overheat protection in the winter- again, this may increase phantom drain because the car is more
active.
c. Checking on your car with the app "wakes it up" and causes a bit of drain. The more you check, the faster it
drains.

2. Use Range Mode unless you can't get enough heat in the car.

3. Don't forget to turn on your Navigation to guide you to a Tesla Charger- Car is programmed to warm the battery faster when it is navigating to a charger.

Keep telling Tesla to give us an option on the App/car to just warm up the battery and see it's status. If you go to a supercharger with cold battery, it is very frustrating how slow it will charge.

Would love to hear other tidbits that people have learned.

Bighorn | 13 décembre 2019

Range mode turns off the battery heater so not a great plan if trying to get to improved efficiency.
Navigating to a SC preheats the battery on the Model 3, but not on my Model S, but it is a 2013.

jordanrichard | 13 décembre 2019

Reds Tesla, "....but Tesla does a terrible job being honest about this issue.", just how are they not being honest?

Are they supposed publish range numbers for every 10 degree increment? Does GM publish different MPG numbers based on where one lives and at what temperature?

There is a degree of expectation that a buyer has done some research before buying a car.

Reds Tesla | 13 décembre 2019

Jordan is correct that the buyer do their research before buying an electric car, but if you advertise a car with a range of 363 miles, which is really about 300 miles (if you charge to the recommended 80%) another loss of 40% brings this to about 175 miles. Because you don't want to drain your battery too low, 175 miles becomes 125miles if you leave only 50miles on the range. The bottom line is to always keep your car plugged in when not in use. The sales people I dealt with in the Boston are do not emphasize this at all, but tout it's impressive range of 360+ miles.

It would also be helpful if someone would clarify the differneces between the model S and 3 for pre-heating the battery. Some think that it is only the 3 that warms up the most by navigating to a Tesla Supercharger, but I was told by a Tesla technician this is true of both models. Not sure what is the answer?

greg | 13 décembre 2019

The "keep the car plugged in" comments are a pretty significant departure from what i thought i had read previously. At some point, i was told to charge the car when it gets to 20% and charge it up to 80% because...
1. this limits the total number of charge cycles, which significantly increases battery life (in years)
2. Keeping the battery at 80% or less is best as far as reducing capacity loss over time

This stuff was beat into my head, and i've literally only been charging maybe once or twice a week because of it. So the new gospel is:
- plugin every night and charge to (80%) so you always have a fairly full battery?
- this won't affect battery longevity or capacity loss?

Can't thank you guys enough for the help.

Bighorn | 13 décembre 2019

@greg
If Tesla had one identifiable tag line, it would be “A plugged in car is a happy car.” I think they were delivering cars with that hang tag. Not sure where you got so far led astray. 20% only seems to come up when folks try to recalibrate their rated range figure. Glad you got that sorted.

bhanuk99 | 13 décembre 2019

Tesla sent a notification called 'Winter driving tips from Tesla" thro the App this evening . Very timely tips that also includes the winter tires and a paid service for anti-ice window treatment.

AERODYNE | 14 décembre 2019

I can second BH on most of his points. Most important, you do not have to go down to 20%, even to recalibrate the BMS. I have never been below 27%.

Don't know what year the OP's car is, but Elon and JB have tweeted the following, summarized below:

For Max battery life, say 20 years, store the car at between 50 and 62%, and try to operate the car mainly from 30 to 70%. (I set the car at 55%, have left it for months, with a calibration error of only 3 miles which goes away as soon as I charge up to 70%)

As far as cold weather, here is what worked for me.
Parked outside at a hotel topped off at a recent SuC , SoC over 50%. Outside temps in the 20's, I plugged in using a 120v outlet. Set scheduled charging a few hours prior to departure. Set the charge limit to 70%. 15 min before departure, stop charging and turn on heater.

AERODYNE | 14 décembre 2019

Also, your phone app should have a new message dated yesterday, regarding cold weather driving. Easier read that this thread.

AERODYNE | 14 décembre 2019

"Than this thread"

Bighorn | 14 décembre 2019

@greg
Right from the Tesla blog:
“Leave Your Tesla Plugged In
We always recommend leaving your Tesla plugged in when it’s not in use. This is especially helpful when it’s cold as staying connected helps your battery retain the heat it needs to operate efficiently and leverage regenerative braking.”

https://www.tesla.com/support/winter-driving-tips?utm_source=notificatio...

CarlE_P439 | 14 décembre 2019

I keep my car plugged in overnight. Therefore turning on climate control does NOT warm up the battery in the morning (since energy is drawn directly from the outlet and not from the battery when the car is plugged in). So I find the most effective way to warm the battery and therefore ALWAYS have (some) regenerative breaking right away NO matter how cold it is to do the following: In the morning, using the App, increase the charging capacity beyond whatever % you normally set it for. Then select “Start Charging” if you use timed charging and the battery will be most effectively warmed up. And you won’t get that irritating notification, “Limited Regenerative Braking.”