Battery Pre heat Charge Time Saved Supercharging

[dusty22]

If the battery is fully preheated enroute to a Supercharger, what is the average percentage of time one can expect to save while charging from 20% to 80% ? I know that many factors are involved such as 150 vs 250 vs 300, weather and such.

 

[Big Earl]

It depends. I’d say 5 to 30 minutes. In extreme cold, it would be more.

 

[LoudMusic]

Comparing a battery that has low state of charge and is preconditioned which can do >240kw for say 5 minutes, versus a battery that has low state of charge and is NOT preconditioned such that it only gets <80kw, it's going to take 3 times as long DURING that initial 5 minutes. So an additional 10 minutes. During that time it will be warming up the battery and hopefully make closer to 'normal' speeds for the remainder of the charging session. But maybe not! It could still be slower than a fully warmed battery making the longer portion of the charging session even longer.

So long as preconditioning the battery doesn't prevent the vehicle from arriving at the charging station, I see no reason to not precondition every single time.

 

[Max Spaghetti]

Really depends on ambient air temp (well, battery temp, but ambient air temp will have a big effect on battery temp).

I rocked up to a 3rd party 350kW charger recently with the car having been outside in 30C all day, and it jumped straight up to 145kW with no pre-conditioning (at about 45% SOC). I don't normally do that - I just decided at last minute to add a bit of charge as I was driving past.

I don't think it would have gone as high in winter temps.

Having said that, there is the factor of what the battery will allow, and what is good for the battery. Just because the car will allow a certain charge rate doesn't mean it's great for longevity to do that all the time. It will be better for the battery to have been preconditioned.

 

[rrolsbe]

Really depends on ambient air temp (well, battery temp, but ambient air temp will have a big effect on battery temp).

I rocked up to a 3rd party 350kW charger recently with the car having been outside in 30C all day, and it jumped straight up to 145kW with no pre-conditioning (at about 45% SOC). I don't normally do that - I just decided at last minute to add a bit of charge as I was driving past.

I don't think it would have gone as high in winter temps.

Having said that, there is the factor of what the battery will allow, and what is good for the battery. Just because the car will allow a certain charge rate doesn't mean it's great for longevity to do that all the time. It will be better for the battery to have been preconditioned.

I agree with your last paragraph but also think Telsa probably priorities getting you down the road as fast as possible even though charging with a slightly cooler battery might not effect long term degradation. My 2018 RWD Model 3, when properly pre-conditioned prior to DC fast charging, would almost always continue sending 4kW of energy to the rear motor stator for at least 20 min during a charging session. Maybe this was necessary but not sure if the additional cost of another kW+ of energy was justified? Early on Tesla only charged for the energy actually added to the traction battery but even then it is possible some small amount of energy was being squandered? If I remember correctly, early on, Tesla did not even pre-conditioned in route.