how long should it take to precondition?

[crackers8199]

we're on a month or so long road trip right now without anywhere to charge where we're staying, so we're pretty much exclusively using superchargers for now. the nearest supercharger is about 20 miles from where we're staying...and whenever we need to charge, i always navigate to it. this usually gives it 20+ minutes or so to precondition.

also, we've stopped at this same supercharger on this trip while we were further away...and it had almost an hour to precondition. in both cases, the car still complained once we got there that the battery temp was low and charging was slower because of it.

so my question is: if even an hour of preconditioning isn't enough to bring the battery up to temp...what's the point? what is the formula to find the magic number as to how long it needs?

 

[DuncanM]

we're on a month or so long road trip right now without anywhere to charge where we're staying, so we're pretty much exclusively using superchargers for now. the nearest supercharger is about 20 miles from where we're staying...and whenever we need to charge, i always navigate to it. this usually gives it 20+ minutes or so to precondition.

also, we've stopped at this same supercharger on this trip while we were further away...and it had almost an hour to precondition. in both cases, the car still complained once we got there that the battery temp was low and charging was slower because of it.

so my question is: if even an hour of preconditioning isn't enough to bring the battery up to temp...what's the point? what is the formula to find the magic number as to how long it needs?

Which M3 do you have? You can always use the app to tell the car to precondition the battery before departure, but my RWD takes a long time to precondition whilst on the road and won't do it when the SOC is less than 20% which is frustrating, to say the least.

 

[crackers8199]

Which M3 do you have? You can always use the app to tell the car to precondition the battery before departure, but my RWD takes a long time to precondition whilst on the road and won't do it when the SOC is less than 20% which is frustrating, to say the least.

2018 RWD LR

if it won't precondition less than 20%, that probably explains most of what i'm seeing. each time i try to run the battery down as low as i can (within reason) before spending the time to drive to the SC. we usually only have to charge once a week, we are staying in a small town with everything pretty close to where we are, and the town does have a level 2 charger i can use if we're out for dinner or lunch near it.

 

[GtiMart]

I've seen the car precondition while under 20% SOC so I don't believe that is a hard rule. The car might not precondition if it believes that will let you stranded...

The battery is a huge mass (1000+ pounds) so it takes a long time to heat. I believe the battery needs to be at 112-120F for an ideal supercharging speed. On cold nights your battery might be starting from 50-60F so it will take a long time. One hour isn't surprising.

EDIT: I see mention of a RWD model... that only has one motor so it cannot generate as much heat as a dual motor, which means it takes even longer.

 

[BigNick]

Did the pre-heatpump Model 3s use the resistive heater to warm the battery at all?

I know my old 2015 Model S P85DL had "Max Battery" which was later named "Ludicrous+" mode, and on a cold (near freezing) day, it could take more than an hour to reach maximum performance temperature which is similar to ideal Supercharging temp and that was using the resistive heater to warm the battery.

 

[GtiMart]

Model S and X have a dedicated battery heater "in the pack". That is not the case for Model 3 and Model Y who use the motors to generate heat that is circulated in the pack (superbottle system). These do NOT use the PTC cabin heater for that purpose. The 2021+ model with heatpump have an octovalve that can circulate the coolant differently. Even then, I believe motors are used to generate heat for the battery but the heatpump might also be used...

 

[BigNick]

Model S and X have a dedicated battery heater "in the pack". That is not the case for Model 3 and Model Y who use the motors to generate heat that is circulated in the pack (superbottle system). These do NOT use the PTC cabin heater for that purpose. The 2021+ model with heatpump have an octovalve that can circulate the coolant differently. Even then, I believe motors are used to generate heat for the battery but the heatpump might also be used...

Thanks for the correction.

 

[804son]

You can also, take a little bit of a long way to the supercharger and drive it hard. Yo-yo the throttle to help generate heat.

 

[Park2670]

Correct, pre-heatpump Model 3 only used the motors to generate waste heat. And also correct, its a huge chunk of metal. It will take a long time to heat up.

I recently transitioned from a RWD Long Range to a Performance with dual motors and with heat pump. And it still takes a long time to precondition when its cold outside.

The good news is the car will only charge as fast as it has been programed to. If its too cold, it will charge slower and not damage anything.

 

[tivoboy]

With the 2018 M3 RWD LR, how long should pre-conditioning really take on a drive? I had a drive yesterday, 112 miles on highway at 75 mph, it was pre-conditioning the ENTIRE time for 90 minutes, used 18.1 miles to pre-condition the battery. Seems REALLY excessive. I’ve often route to a TOWN near the SC, and only routed to the SC when within about 50 miles, so it uses less battery for pre-conditioning. I always get to the SC and managed 254kw so max input so not really sure why the car tends to try and PC, and waste so much energy. At my rate of speed and usage, that’s about 4.5 kw just wasted.

 

[A2be]

With the 2018 M3 RWD LR, how long should pre-conditioning really take on a drive? I had a drive yesterday, 112 miles on highway at 75 mph, it was pre-conditioning the ENTIRE time for 90 minutes, used 18.1 miles to pre-condition the battery. Seems REALLY excessive. I’ve often route to a TOWN near the SC, and only routed to the SC when within about 50 miles, so it uses less battery for pre-conditioning. I always get to the SC and managed 254kw so max input so not really sure why the car tends to try and PC, and waste so much energy. At my rate of speed and usage, that’s about 4.5 kw just wasted.

You need to provide a bit more information for informed people to speculate.

What was the outside temperature during your 112 mile drive? What temp was the car stored in during the 10 to 16 hrs before your trip?

I had a 2019 M3, and it used the inefficient electric means of heating things, a PTC air heater. By my 2022/2023 Model Y's, they are using the much more efficient heat pump system (with octovalve; to collect heat from nearly a dozen different places in the car and reuse it where needed). The newer system can easily use up to 2/3rds less electricity to provide heat.

So the temp environment, and the inefficient type of heating system in a 2018 M3, are both something for you to think about in answering your question.

 

[tivoboy]

You need to provide a bit more information for informed people to speculate.

What was the outside temperature during your 112 mile drive? What temp was the car stored in during the 10 to 16 hrs before your trip?

I had a 2019 M3, and it used the inefficient electric means of heating things, a PTC air heater. By my 2022/2023 Model Y's, they are using the much more efficient heat pump system (with octovalve; to collect heat from nearly a dozen different places in the car and reuse it where needed). The newer system can easily use up to 2/3rds less electricity to provide heat.

So the temp environment, and the inefficient type of heating system in a 2018 M3, are both something for you to think about in answering your question.

Avg. outdoor temp for the drive was 54, overnight low (vehicle was stored outside) was 45.

 

[jjrandorin]

I dont know how long it should take to pre condition, however I do know that during what passes for winter here (I am in SoCal, which is generally warmer than NoCal) I can drive 40-45 miles at 80-85 mph and still have regen dots on my display at the end of that drive, when I get to work.