Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

New owner, have a question on battery temp management

hahler2

Member
Feb 10, 2017
25
4
South Dakota
Hey guys! Long time lurker, new owner here! I took delivery of my Model 3 stealth about 2 weeks ago. I LOVE the car! It's absolutely fantastic! I don't know why I held off so long in pulling the trigger!

So I live in NE South Dakota. Winter and cold weather is very much a big concern here. I did lots of research on range loss and how to minimize loss in the winter time. I understand the 3 does not have the dedicated battery heater like the X and S do. From everything that I read it seems the best method is to make sure that the car either finishes charging right as it's time to leave, or to raise the charge limit before leaving. This will heat up the battery pack. Also to make sure and preheat the cabin extensively while plugged into shore power. No big deal. I can handle that.

So yesterday we decided to take a little road trip in the car. See how it does in crappier weather and see how the whole supercharging thing works. All that stuff. It was about 45 degree's outside and the wind was really blowing! About 25 to 30 mph! My garage is insulated, but not heated. So about an hour and a half before leaving I raised the charge limit from 90 to 100 percent. A half hour before leaving I started preheating the cabin. Figured I should be good to go. Jump in the car and take off, and I still have very limited regen. Maybe 50 percent. Thought, ok, no big deal. I just didn't charge long enough to warm it up fully. So we drove about 110 miles. Had full regen by the time I had gone 15 miles. Got to our first Supercharger, plugged in, and walked to nearest place to grab some lunch. Finished eating and car was almost done charging (certainly had plenty to make it to the next destination) and jumped in the car and left. Even after supercharging for about 30 minutes, I had limited regen on battery. I guess I would have thought that a Supercharger going into a warm battery would have been enough to keep it warm? So I'm kind of confused on how it all works. Just want to make sure I fully understand all the systems before winter really sets in here and it gets really cold.
 

gilscales

Active Member
Jul 16, 2016
1,684
1,905
Long Beach, CA
I'm in Southern CA, we all start whining when it dips below 60! sorry I can't be any help here but I will grab some popcorn and watch this thread!
 

Feathermerchan

Active Member
Sep 21, 2018
1,169
908
Euless, Tx
Did you charge the battery to 90-100%? If so regen could be limited because of state of charge. ie there is no room for more charge in the battery.

On another note a recent software update added a feature where if you use the navigation to go to a Supercharger and the battery is cold, the car will warm the battery as you drive in preparation for charging. This will make the charging faster.

The car uses the inverter and motor to heat the battery even when standing still or parked. The inverter is ordered to send current thru the motor but produce no torque. The coolant is circulated and picks up heat from the motor and inverter and heats the battery.
 

hahler2

Member
Feb 10, 2017
25
4
South Dakota
I did. I charged to 95 percent. Didn't intend to charge that high, but kids took forever to eat! That explains a lot! I didn't even think about the SoC being to high to add anymore from regen. Thank you!

So you're saying that when it's parked outside and the battery gets to cold, it will start using the inverter to warm the battery? I did not know that! Will definitely have to make sure that it's plugged in at all times in the garage so it can pull power from the wall to do that, rather than the battery pack.
 

Camera-Cruiser

Fully Charged
Dec 4, 2015
773
795
Fullerton, CA
You can’t put more gas into a full tank, or more charge to a full battery. Regen needs space to go. You gave it no space. I wouldn’t worry to much about temp management unless you are an edge case (meaning your daily commute is always using up most of your battery to the point of range anxiety). I charge to 90% daily and set my start time to 3:00-4:30am based on what I need to add to be able to drive at 7:15am. That way pack is warm and I still have regen.
 
  • Helpful
Reactions: Rocky_H

hahler2

Member
Feb 10, 2017
25
4
South Dakota
You can’t put more gas into a full tank, or more charge to a full battery. Regen needs space to go. You gave it no space. I wouldn’t worry to much about temp management unless you are an edge case (meaning your daily commute is always using up most of your battery to the point of range anxiety). I charge to 90% daily and set my start time to 3:00-4:30am based on what I need to add to be able to drive at 7:15am. That way pack is warm and I still have regen.

Yeah that totally makes sense. I just had a complete brain fart and didn't think about that.

As far as charging, that's exactly what I plan on doing, and how I have it setup at the moment. I'm not overly worried about temp management as most days the car won't be driving far enough on a day to day basis for it to be an issue. I just like to understand how all the systems work.
 
  • Like
Reactions: gilscales

derotam

Member
Oct 31, 2018
825
702
Oak Hill, VA
So you're saying that when it's parked outside and the battery gets to cold, it will start using the inverter to warm the battery? I did not know that! Will definitely have to make sure that it's plugged in at all times in the garage so it can pull power from the wall to do that, rather than the battery pack.

So someone can tell me I am wrong...if they have data to share...but there is a statement in the manual about not leaving the car in ambient temps below -22F for over 24 hours at a time. Because of that statement, I am going to assume(because I can't test it), that the car is not going to use battery power while parked to warm the pack(using motor heat).

Also note, that generally, you aren't going to be able to charge if the pack is below 0F, and from batteryuniversity.com "According to research papers, the allowable charge rate at –30°C (–22°F) is 0.02C"

Some people have said that if you turn on the cabin heat that that would warm up the pack, but I think that is only going to be due to either the discharging of the pack, or heat transfer from the floor/pack physical connection. Again, I could be wrong, but I never saw anyone provide data to support anything else.
 

RobC

Member
Apr 4, 2016
106
63
Philadelphia PA
Some people have said that if you turn on the cabin heat that that would warm up the pack, but I think that is only going to be due to either the discharging of the pack, or heat transfer from the floor/pack physical connection. Again, I could be wrong, but I never saw anyone provide data to support anything else.

Im pretty sure turning on the cabin heat only preserves battery charge by drawing the heating power from the shore line. It might have some slight affect on battery temp but cant imagine it is much more than charging alone.
 

derotam

Member
Oct 31, 2018
825
702
Oak Hill, VA
Im pretty sure turning on the cabin heat only preserves battery charge by drawing the heating power from the shore line. It might have some slight affect on battery temp but cant imagine it is much more than charging alone.

Absolutely. But that didn't stop a lot of "just turn on cabin heat to warm up the pack" statements that were made last winter. We will have a whole new round of various winter related "issues" this year I am sure.
 

rrolsbe

Member
Feb 18, 2017
233
129
Albuquerque
From memory follows is my limited experience with traction battery heating last winter. BTW, I was born in SD and lived all over the state through the 8th grade which was a long time ago. My Model 3 stays parked in my garage unless I am out about town or on a road trip. When the garage temperature got down to around 47F, part of my 24A @ 240V charging power was used to heat the battery using the traction motor. When the temperature got down to around 40F, all of this power was used for a 10 to 20 minute time period to only heat the traction battery. Then the charging slowly ramped up to the normal 22MPH charge rate and the traction motor stopped creating heat (no sound at rear of car). When the car is awake the traction battery/coolant temperature does appear to raise slightly due to the power being drawn. I verified this by using my handheld IR temp reading device pointed at the Superbottle. AFAIK, the traction battery is not actively cooled/heated unless the car is being driven or actively being charged; however, I though if the temp was below -22F? or above 120F? the BMS would use traction battery and/or shore power to maintain a safe temp. If not enough shore power is being provided to maintain a safe temp range or the car is not plugged in, the traction battery will eventually deplete which could ruin the battery/brick the car. From what I have read on the forums, the traction motor uses a maximum of around 7 to 8KW? for heating proposes. On a cold SD night parked outside during a blizzard at -30F, I am not sure that would create enough heat to keep the traction battery temp above -22F? Forum members please feel free to correct anything incorrect is this post as I want to understand correctly as much as possible about this topic.
 
  • Informative
Reactions: go2realize

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top