Battery warming in cold climates - how much energy?

[Moderatefan]

Tesla Model 3 Road Trip
This post states ~134 miles/day may be lost in -13F while parking. Can others chime in with their loss numbers and respective outside temperatures?

Also, do we know what will happen to the battery in the cold after it's fully drained?

 

[streetskooler]

I think you converted kilograms to pounds not kilometers to miles.

Anyway the range lost is about 33 miles which is a lot but that’s pretty cold weather.

 

[Moderatefan]

I think you converted kilograms to pounds not kilometers to miles.

Anyway the range lost is about 33 miles which is a lot but that’s pretty cold weather.

That's per 6 hours, so if warming is continuous we should times 4. If we assume the battery freezes solid and then only takes 33 miles to unfreeze, then it's much better. I think we need to see losses over time in the same temperature to better understand what happens. Unless it's in the M3 documentation somewhere.

 

[streetskooler]

Ah I see you’re right, my apology. Hopefully as more deliveries are made outside of sunny California we’ll get more info on colder climates. It’s 11 degrees Fahrenheit now where I’m at so I’m interested to know

 

[gregincal]

That's per 6 hours, so if warming is continuous we should times 4. If we assume the battery freezes solid and then only takes 33 miles to unfreeze, then it's much better. I think we need to see losses over time in the same temperature to better understand what happens. Unless it's in the M3 documentation somewhere.

Warming is not continuous. It happens only when you start the car (power will be limited until the battery is warm, but the software deducts the range up front). The amount lost will be the same after 6 hours or 24 hours or one month. The battery stays cold and the car warms it when you get in to drive. That's why people call it a "cold soak", because the battery gets really cold and takes a lot of energy to warm up.

 

[gregincal]

Ah I see you’re right, my apology. Hopefully as more deliveries are made outside of sunny California we’ll get more info on colder climates. It’s 11 degrees Fahrenheit now where I’m at so I’m interested to know

Plenty of people already own Teslas in those climates. The Model 3 isn't that different.

 

[Moderatefan]

I think there was something technically different about battery warming in M3 compared to S/X, but would need to look this up.

I did find these notes in the old manual:

Discharging the Battery to 0% may permanently damage the Battery. To protect against a complete discharge, Model 3 enters a low-power consumption mode when the charge level drops to 5%. In this mode, the Battery stops supporting the onboard electronics to slow the discharge rate to approximately 4% per month. Once this low-power consumption mode is active, it is important to plug in Model 3 within two months to avoid Battery damage. When the low-power consumption mode is active, the auxiliary 12V battery is no longer being charged and can completely discharge within 12 hours.

For better long-term performance, avoid exposing Model 3 to ambient temperatures above 140° F (60° C) or below -22° F (-30° C) for more than 24 hours at a time.

That's temperatures we have in the Northeast right now.

 

[Moderatefan]

I think couple of things here I saw in the past made me suspicious: Tesla Model 3: Exclusive first look at Tesla’s new battery pack architecture

For example, it got rid of the external battery pack heater and instead, it heats the pack only using heat provided by the powertrain even when the car is parked....Tesla apparently judged the system efficient enough to not include an external battery pack heater in the Model 3 and replaced it virtually entirely through software.

Even when parked, Tesla’s software can send a request to the powertrain inverter to start powering up and pass the appropriate currents to the motor in order to produce enough heat to warm the cells – all while not producing any torque so the Model 3 doesn’t move.

But I don't see anything explicit about continuous charging, so could be it's a non-issue. If you don't expose it for more than 24 hours to extreme cold(per manual) and have at least some range left before parking outside.

 

[gregincal]

I think there was something technically different about battery warming in M3 compared to S/X, but would need to look this up.

I did find these notes in the old manual:


That's temperatures we have in the Northeast right now.

Yes, but notice they say “for long term performance”. They are just warning you that parking your car unprotected for long periods in those temperatures could lead to some battery degradation, not that anything catastrophic will occur. The battery degradation will occur exactly because they aren’t using energy to heat the battery when it’s left parked.

 

[david_42]

No big deal for us, but looking at the new manual, I can't find anything about the battery being kept warm if the car is plugged in. I can see letting the battery cool if it is not plugged in, but if it is I'd think it would be advantageous to keep it warm (above freezing at least).

 

[DavidP]

Yes, should be really helpful if the battery kept warm when plugged inside a 110V outlet. So never worried about cold loss, wherever you are (110V always near).

Hoping they will improve the performance in cold temperature.

 

[Mags]

I just got a new-to-me 2013 Tesla S85. "Nur Tessa". Yup, over the moon! And I am concerned about the above post by Moderate Fan which states " For better long-term performance, avoid exposing Model 3 to ambient temperatures above 140° F (60° C) or below -22° F (-30° C) for more than 24 hours at a time." We have been having some pretty cold temps.... below - 30 degrees C for a few days in a row. Ours is an unheated garage. The only way I can think of avoiding exposing our car to that is to by overnight parking at a heated garage downtown, or drive south! How do the rest of the cold weather folks handle that?

 

[gregincal]

I just got a new-to-me 2013 Tesla S85. "Nur Tessa". Yup, over the moon! And I am concerned about the above post by Moderate Fan which states " For better long-term performance, avoid exposing Model 3 to ambient temperatures above 140° F (60° C) or below -22° F (-30° C) for more than 24 hours at a time." We have been having some pretty cold temps.... below - 30 degrees C for a few days in a row. Ours is an unheated garage. The only way I can think of avoiding exposing our car to that is to by overnight parking at a heated garage downtown, or drive south! How do the rest of the cold weather folks handle that?

Note that it just says "for better long term performance". i.e. you might get some extra battery degradation, but it's not clear how much it really matters. Also, if you just activated battery preheating once a day (or actually drove the car) that should solve any problems.