Is this supercharge speed normal?

[awww]

Sounds like what I experienced during the December cold spell. Around -10C outside at the Comber supercharger, arrived at 22% and charge rate topped out at 85kw before tapering. The car was plugged into a level 1 outlet all day (surprisingly got like 45km of range in 12 hours at 12A) and driven on the highway for over 30 minutes on route.

 

[Darthbenji]

Dude it’s -13 today. It’s going to be slow no matter what.

It likely depends on the temperature. The rate of heat loss from an object is proportional to the difference in temperature between it and the outside world. So the colder it is outside, the faster the rate of heat loss. There is a maximum amount of heat that can be pumped into this system from the motors (something like 7kW), so as the system warms up, heat loss will increase, and eventually an equilibrium will be reached and the pack will no longer continue to warm up. So it may be that your battery can never reach the optimal temperature in extremely cold temperatures, even with 7kW being pumped into it.

That being said, if you do not receive maximum rate at a Supercharger, and it's very far off the max rate, it's usually worth trying a different one right away, if you think your battery is warm.

Thanks.

 

[Big Earl]

Thanks. I wonder how much heat loss is from the plastic pipes with coolant in them and how much is from the battery itself? Someone should get some foam pipe insulation and put it on all the pipes! There would be no way to measure the improvement though. My guess is that it's a significant source of loss but maybe the battery surface itself dominates.

Heat loss through the coolant hoses is minimal compared to the heat loss from the thin metal battery pack. There isn’t enough room in the pack for a bunch of insulation, so it will shed heat quickly.

Also keep in mind the wind chill effect from driving on the highway. While wind doesn’t cause an object to drop below ambient,* it does cause the object to shed heat and reach equilibrium with ambient more quickly. So traveling at highway speed will cause the battery’s heat to dissipate at a faster rate than if the car was stationary.

*evaporative cooling can cause an object’s temp to go below ambient

 

[AlanSubie4Life]

Heat loss through the coolant hoses is minimal compared to the heat loss from the thin metal battery pack. There isn’t enough room in the pack for a bunch of insulation, so it will shed heat quickly.

Guess someone should glue a bunch of Thinsulate to the bottom of the pack and report back.

3M Thinsulate (TM) SM200L Acoustic Thermal Automotive Insulation for van and car | eBay

Probably going to need to put a waterproof barrier on it too, and it's going to hurt your ground clearance (expands to 1/2").

 

[Kevy Baby]

I drive about an hour navigating to a super charger...

I might be missing something, but you're not driving an hour to a Supercharger just to charge and then an hour back home are you?

 

[Darthbenji]

I might be missing something, but you're not driving an hour to a Supercharger just to charge and then an hour back home are you?

Ha ha ha. No. I was going about 20 minutes beyond it and knew I wanted to charge there so I used it as the destination.

 

[rrolsbe]

I would assume a fair amount of heat is being lost from the traction motor(s) and inverter(s) housing surfaces at very cold temps not just from the coolant lines and traction battery surfaces.