Battery charging in snow and very cold weather

[RickW]

Hi,

I have owned my Tesla for two years now and I have been meaning to ask this question.
I charge my car to 80% every evening before going to work and leave it plugged in on weekends.
I have a Tesla wall charger.
On days when I know that it is snowing or if the temperature outside gets in the 30's, I have increased
my charge to 90%. If the same happens the following day, I charge to about 83-85%.
I've found that my trip, to and from work, without deviation, usually takes the car from 80% to 68% in the summer,
but in the winter, it will drop to 55-58%. The heater is used (I see no point in sitting in a cold car) and sometimes
the defroster has to be used and I do use Sentry Mode.
I guess the question is do you increase the max battery charge on very cold days (for some of you I understand that will in the teens or 20's)
or do you keep it the same and only make adjustments for long trips?

Thanks

 

[derotam]

Only reason to increase the max charge would be for range anxiety due to extra losses due to winter time. As far as the car is concerned, it doesn't matter. I only charge mine to 60% daily and don't plan on increasing it due to winter, still have plenty of buffer for my drive and end up at probably 30% when I get home in the evening.

 

[GtiMart]

Exactly. My typical daily use is 3-10% in the summer so it won't exceed 6-20% in the winter. I continue to charge to 55% unless I know I need to go farther. The only difference in the battery is that if you let it get cold, there will be up to 5-7% SOC that you cannot use until the battery heats up. As long as you have enough even when counting for that, why would you charge more?

 

[RickW]

Only reason to increase the max charge would be for range anxiety due to extra losses due to winter time. As far as the car is concerned, it doesn't matter. I only charge mine to 60% daily and don't plan on increasing it due to winter, still have plenty of buffer for my drive and end up at probably 30% when I get home in the evening.

Thanks that helps. I think that I'm a little anxious about range if I get caught in a snowstorm or something like that. additionally, I've been reluctant to get the car under 50%. It really stays within that 60-80% range. After reading this, I might just go ahead and let it drop to 40. Thanks.

 

[RickW]

Exactly. My typical daily use is 3-10% in the summer so it won't exceed 6-20% in the winter. I continue to charge to 55% unless I know I need to go farther. The only difference in the battery is that if you let it get cold, there will be up to 5-7% SOC that you cannot use until the battery heats up. As long as you have enough even when counting for that, why would you charge more?

thank you.

 

[Candleflame]

Hi,

I have owned my Tesla for two years now and I have been meaning to ask this question.
I charge my car to 80% every evening before going to work and leave it plugged in on weekends.
I have a Tesla wall charger.
On days when I know that it is snowing or if the temperature outside gets in the 30's, I have increased
my charge to 90%. If the same happens the following day, I charge to about 83-85%.
I've found that my trip, to and from work, without deviation, usually takes the car from 80% to 68% in the summer,
but in the winter, it will drop to 55-58%. The heater is used (I see no point in sitting in a cold car) and sometimes
the defroster has to be used and I do use Sentry Mode.
I guess the question is do you increase the max battery charge on very cold days (for some of you I understand that will in the teens or 20's)
or do you keep it the same and only make adjustments for long trips?

Thanks

When its cold you dont get much degradation from soc. You could literally leave the car sitting at 100% all the time and itll still get less stress than at 25c at 50%

 

[father_of_6]

It really stays within that 60-80% range.

It's actually typically healthier for the battery to sit at a lower state of charge.

For the consumption you stated (at most 30% per day), I would recommend setting it to 60%.

Bump it up the night before when you know you have extra driving to do the next day.

 

[Birdsfan]

I will charge my battery to 90% couple times a week. All the Tesla literature states it's okay to do so, I understand there is A LOT of battery charging information out there. End of the day it's a car that I may keep for 3-5 years, I'm not concerned about it. The Tesla service tech that has serviced my vehicle a few times drive a model X and supercharges it daily, he's had his SUV for several years and told me has hasn't had battery issues. Of course ymmv.

 

[Terpman90]

It's actually typically healthier for the battery to sit at a lower state of charge.

For the consumption you stated (at most 30% per day), I would recommend setting it to 60%.

Bump it up the night before when you know you have extra driving to do the next day.

^^This.^^

I used to charge mine to 90% daily, and watched the fully charged range drop significantly. Now, I charge only to 70%, and the BMS adjusted so that I got most of that range back. The BMS is far better able to determine range when it has data at lower SOCs. My recommendation would be to charge as much as you need to (plus a buffer), and no more.

 

[derotam]

Thanks that helps. I think that I'm a little anxious about range if I get caught in a snowstorm or something like that. additionally, I've been reluctant to get the car under 50%. It really stays within that 60-80% range. After reading this, I might just go ahead and let it drop to 40. Thanks.

You aren't going to get blindsided with not enough energy to get home if you just pay attention to how your energy usage trends. You can reduce your max charge a bit, drive for a couple days at x outside temperature and see where you are at the end of the day and then lower the charge level again if you are comfortable.

Personally I think my limit is 20% at the end of the day. If I'm going to be below that, then I would raise the charge limit a bit. Where does 20% come from? Just picked a value...it's like saying I won't let my gas car go below 1/4 tank or whatever amount before getting gas.

 

[GtiMart]

Same here. When I got the car I would charge to 80-90% in winter, only to end back home at 77%... After one winter I understood that I didn't need it. I was also doing it to get more performance as the car is faster when the SOC's higher... but temperature trumps it all, a cold battery is slow whatever the SOC. Since then I'm doing something similar to @derotam

 

[father_of_6]

Personally I think my limit is 20% at the end of the day. If I'm going to be below that, then I would raise the charge limit a bit. Where does 20% come from? Just picked a value...it's like saying I won't let my gas car go below 1/4 tank or whatever amount before getting gas.

I was a bit range-concerned in the beginning (never anxious though), but at this point I'll go as low as -1%. At about 3 miles per %, that's not too long of a walk home.

 

[Tonedog77]

landed at a few supercharger this past weekend when it was 10 degrees outside with 2% and then on the way home a few days later 4%. living on the edge lol

 

[rotom3]

I did this at first due to range anxiety, but it was just that - range anxiety. I only increased it minimally (85-90% instead of my normal 80%), but I ended up not really needing the extra range. Didn't hurt to at least try it out for a bit

 

[Stew-2]

It’s interesting how we all have our routines lol. My commute is around 42 miles and I normally daily charge to 50% although I did bump it up to 53% a few weeks ago due to the cold weather just to give me a little peace of mind.

My schedule changes week to week and with my commute I can get two days of driving at 50%, and this has saved my bacon a few times when I’ve forgot to change my scheduled charge time when my new schedule comes out.

I’ve been charging like this almost since it was new, 10 months ago, and there’s no apparent degradation yet. Tonight I got home with 104 miles(33%) remaining, 104/0.33 extrapolates to 315.15 miles at 100%

Yeah I’m giving up some performance driving in the lower half of the battery but I’m just commuting, plus when I do charge higher on special occasions it’s extra fun! I tend to keep my cars for a long time so this works for me.

 

[KenC]

I did this at first due to range anxiety, but it was just that - range anxiety. I only increased it minimally (85-90% instead of my normal 80%), but I ended up not really needing the extra range. Didn't hurt to at least try it out for a bit

Yep, I got mine in the middle of winter, Dec 2018, so I started keeping my SOC at 90%. Then by March, I dropped it to 80%. Then in the Summer, reading some of the threads here, about degradation, cathode cracking and anode plating, I dropped my level to 60%, since I only have a <30mile commute. So, 60% to 50% and back. Since then, I've kept it at 60% at home, and whatever charge I need on roadtrips.

Anecdotally, it's been great. Still have 76.4kWh out of 77.8kWh when new, now just 4yrs + 1 day old.

As you can see I got home with 49%, a little lower than my norm, but it was a blue snowflake day. Battery pack was 42F.

 

[WhtLghtning]

Good info in here. I just purchased a used 2019 that only has 15k miles. I commute 50m a day plus other activities with my kids daily. I charge to 80 and get home at night with just under 40%. If I know I won't be driving much, or at all, I charge to 60% and leave it in the garage.

Thinking of dropping to 70% and running 70% to 30%...

 

[WhtLghtning]

Also, I am yet to drive in warm weather so things may change in march!

 

[reefer_bob]

I'm commuting ~130 miles total a day. It generally takes 50-55% charge in total. I try to charge to 70% (while at work) so I can get back to work the next day and still be over 20% SOC. Depends on traffic/temperature/rain/etc.

Now during the winter (mild winter in nor-cal), I'll trickle charge my car at 230v/5a when my electricity rate goes off peak at home, and pre-condition before I leave for work. I'd rather do the pre-con while plugged in and not take those extra bits of charge.

I don't trickle charge or schedule departure in the summer.

 

[father_of_6]

Good info in here. I just purchased a used 2019 that only has 15k miles. I commute 50m a day plus other activities with my kids daily. I charge to 80 and get home at night with just under 40%. If I know I won't be driving much, or at all, I charge to 60% and leave it in the garage.

Thinking of dropping to 70% and running 70% to 30%...

I suspect once you're more comfortable with the car, you'll end up running 60-20%, or 65-25%. That's even healthier for the battery.

Once the warmer weather comes your range will definitely improve.