Now this is interesting

[gpsman]

In hybrid cars (that have electronic throttle) if your foot is on the brake even a little bit (enough to trigger the brake lamp for example) the electric drive motor is disabled and the gas engine goes to idle.

You can’t rev the engine to warm it up faster, and it makes it near impossible to smoke the tires.

On the Chevy Bolt, you CAN press the throttle and brake at the same time. You CAN run the electric drive at full output and drag your hydraulic brakes at the same time.

So here’s the question and why I tried this experiment in the first place.

We just had an unusually cold night and I had to park outdoor all night.

My battery is only 40% and I want to visit a DCFC right away and then get on with my day.

Is it helpful to do a few full throttle pulses follwed by a few full regen pulses to internally heat up the battery on the way to the DCFC?

At 32 degrees F I think DCFC rate is about cut in half.
It begins to slow down at below 60’F.
But it is battery temperature that matters, not the outdoor temperature.

 

[WetEV]

But it is battery temperature that matters, not the outdoor temperature.

Wouldn't a battery temperature readout be useful?

(Hello GM!)

 

[EldRick]

It takes a LOT of heat to warm a half-ton of battery. A couple of quick regens and accelerations is only going to burn a kWH or two at most, and most of that isn't going into heating.
Unlikely to have much effect.

 

[Zoomit]

Sure, it's not very civil but rapid acceleration and regeneration is a fast way to heat up the battery to accept a faster DCFC rate. Here's a good example shown with a Tesla.

https://www.youtube.com/watch?v=c1C-tPkevIA

 

[gpsman]

Zoomit- thanks.

That’s pretty much what I thought.
In the Ford Hybrids at least, this was a proven method programmed into the car using NiMH batteries.

We would observe the car doing several deep discharges and deep recharges in cold weather.
Usually 3 to 6 times would do it.