Cold Weather Supercharging

[Skotty]

I've had some opportunities now to supercharge is very cold weather.

It should be noted that I typically charge after my car has been sitting outside for awhile. Usually I spend at least a half day at an office (sometimes as much as a full day 24 hrs) before driving a short distance to the supercharger. So most of my experiences have been on a somewhat cold soaked car. I suspect the situation is better for normal travel without the long periods of sitting out in the cold unplugged.

The charging rates I have experienced have been anywhere from 16 kW up to about 70 kW, much lower than warm weather charging. The kW rate tends to start low and slowly climb while charging, before tapering back off when near full. Starting at about 35 to 40 kW seems common. The time it started at a measly 16 kW it was very cold and the battery was near empty. Temperature ranges during this sampling have been from about 5 F up to maybe 30 F.

Another note: the car is regen limited when first heading out after the car has been sitting in cold weather. Regen capability slowly climbs as you drive the car, but it can start at almost nothing.

I have a 2014 P85.

I don't view this negatively or positively. Just interested in what can be expected.
Would like to hear what others have experienced in this regard.

 

[Chrisizzle]

As you've noted, the car won't even let the regenerative braking charge the car when batteries are cold. So, yes... supercharging is slower when batteries are cold. You'd get better results of you warm the battery prior to charging.

 

[Barry]

Plan your time to charge immediately after your drive, while the battery is still warm.

 

[Villa-Lobos]

Traveled all thru Canada in 0-10F never a problem as the charge rates often started at 350 mi /hr but always charged right after driving the car for at least an hour. As Berry says always charge after you drive so the battery can handle what the supercharger can give it.

 

[bonaire]

When very cold, cells should be warmed up for best longevity. Battery University is a little extreme here when describing cold temp charging - but read link below. It's a good idea to keep an EV plugged in, especially in winter, so the battery TMS (temperature management system) works off the grid power.

Charging at High and Low Temperatures

 

[wraithnot]

I've had some opportunities now to supercharge is very cold weather.

It should be noted that I typically charge after my car has been sitting outside for awhile. Usually I spend at least a half day at an office (sometimes as much as a full day 24 hrs) before driving a short distance to the supercharger. So most of my experiences have been on a somewhat cold soaked car. I suspect the situation is better for normal travel without the long periods of sitting out in the cold unplugged.

The charging rates I have experienced have been anywhere from 16 kW up to about 70 kW, much lower than warm weather charging. The kW rate tends to start low and slowly climb while charging, before tapering back off when near full. Starting at about 35 to 40 kW seems common. The time it started at a measly 16 kW it was very cold and the battery was near empty. Temperature ranges during this sampling have been from about 5 F up to maybe 30 F.

Another note: the car is regen limited when first heading out after the car has been sitting in cold weather. Regen capability slowly climbs as you drive the car, but it can start at almost nothing.

I have a 2014 P85.

I don't view this negatively or positively. Just interested in what can be expected.
Would like to hear what others have experienced in this regard.

Here's my experience

"It's hard to figure out exactly how battery temperature affects supercharger rates because we don't have direct access to the battery temperature. But I learned the hard way to always supercharge right after arriving at a destination rather than waiting until the morning when it's cold outside. At rapid city, I got 120 kW for a bit, but decided to call it a night and finish the next morning. The next morning after a somewhat cold night the charge started at something like 30 kW despite a really low state of charge and maxed out at 50 kW before the taper started lowering the rate again."

Opinions on Supercharging rates/reporting

 

[bonaire]

wraithnot, Exactly - based on the various things I've read, there are some issues within the chemistry itself of Lithium Plating going on during very cold charging cycles. Some of these issues were all part of that infamous situation brought to light by John Broder in winter 2012-2013 and overnight range losses due to cold soaks. Don't be a "Broder" and do charge right after driving and not after a long cold soak. And here is the story: Stalled on the E.V. Highway

 

[Skotty]

Here's my experience

"It's hard to figure out exactly how battery temperature affects supercharger rates because we don't have direct access to the battery temperature. But I learned the hard way to always supercharge right after arriving at a destination rather than waiting until the morning when it's cold outside. At rapid city, I got 120 kW for a bit, but decided to call it a night and finish the next morning. The next morning after a somewhat cold night the charge started at something like 30 kW despite a really low state of charge and maxed out at 50 kW before the taper started lowering the rate again."

Opinions on Supercharging rates/reporting

Good advice. Hard for me to personally follow though. A typical work trip for me has me staying for 2 days in a place where charging basically doesn't exist, with the exception of the supercharger station. I could charge as soon as I arrive, but it's a less efficient travel route. Might be worth it for the faster charging though. Still, I'd probably have to top off before heading back home, even if I charge after I arrive (due to 1 or 2 days of driving around town with a long trip home in the cold) and there's really no way to fix that.

Thanks for the link to the other thread.

 

[Boourns]

According to Doug's recent post, preheating the cabin with the phone app also begins to warm the battery. It is a bit wasteful, but I wonder if the car would charge faster if you preheated the cabin for a few minutes before you left. Of course you'd want to make sure you have enough charge to get to the SC and also that the quicker supercharging speed would positively offset the extra time it took to recoup energy used to preheat.

 

[andrewket]

Plan your time to charge immediately after your drive, while the battery is still warm.

^ this. If possible, you would have better results driving to the SuC in the morning and then going to work.

 

[wweiss]

2013 P85 (145K miles): Just bumped into this limitation this morning in CT, 13F and car left out all night. Brought into a warm garage and HPWC'd @ 80A and... nothing - until 35min later when gradually the counter ticked up towards the full 57mph @ 80A

 

[scottm]

Well.. it wasn't doing nothing.. it was heating the battery until it could take on charge... and then it did.

When I know I'm going to be supercharging soon, I'll make sure the range mode = OFF in the car as I'm driving along, so car is more liberated in applying more heat to everything... including the batteries.

This helps get up to higher charge currents sooner in the cycle, when I do arrive at SC.

So even if I'm at 30% and I know it takes 25% to get to destination on a mild day... kick range mode to OFF for the whole trip... as a form of "pre-heating for the purposes of charging"