Model S Cold Weather Charging

[APD1080]

For the past 3 days I have had some very bad results using the supercharging station at Cranberry, PA. We own a 2016 Model S 90D. On 3 consecutive days (January 6, 7 & 8) I have tried to charge with dismal results. The outside temperature on those days was 15-20F. My car is in an unheated garage. when I plug in the charging rate the cat shows was 4 kW (on the 6th), 11 kW (on the 7th) and 0-1 kW (on the 8th). on all 3 days I stayed plugged in for at least 1 hour and the charge rate never improved. Another thing was the estimated time to full charge was 40 minutes (on the 6th with 100 miles to go and at 12 mi/hr (4kW)), 50 minutes (on the 7th with 140 miles to go at 38 mi/hr (11kW)), and 50 minutes (on the 8th with 150 miles to go at 2 mi/hr (0-1 kW). The same information is on the Tesla phone app which shows amps instead of kW (the car used to show volts and amps but it seems the latest update changed it to useless kW.

Has anyone else experienced this kind of issue with low kW at supercharging stations? I think I have a problem with the car.

 

[Chopr147]

May be the obvious answer but it's the cold weather. I think it's the battery protecting itself.

 

[kort677]

if the battery is cold it will limit charging at a SpC, if you live there why aren't you charging at home?

 

[APD1080]

The SpC is close to a Starbucks and other restaurants that I frequent so it is easy to just plug in and get a full charge when I am out an about. However I do not see how 15-20 F temperature should cause such a significant drop in SpC performance. The charging rate is less than home charging. If this is truly the case of battery protection then how does anyone in Canada when the temperature gets to negative degees F charge?

 

[juliusa]

Normally the battery is warm when you arrive at a supercharger on a trip, so it charges at full speed even at 0F temperatures. For people that park on the street or other places where they cannot charge overnight, it is a challenge.

 

[APD1080]

How long do you have to drive to get a "warm" battery. On the 7th I drove for ~45 miles before stopping to charge. I did not have the "blue battery" restriction so I do not know at what temperature is is "too cold". It woudl seem to me that after 45 minutes of driving and never getting the "blue battery" restriction that my batteries should be warm enough to charge faster than what I get on a 220V 50 amp home charge.

 

[DarkMatter]

What was your state of charge? On the 7th you arrived warm, and had the highest charge rate. However if you were in the top 20% of the battery you still could have been in the taper. Superchargers really do work best from a low SoC with a warm battery, the ideal conditions for road trips. Regular L2 charging should be your go-to if possible.

 

[APD1080]

On the 7th I was at 120 miles ~40% of charge so I should have been on the high rate slope. I should not start to taper off until around 220 miles. Being an engineer I have been tracking the various charge rates versus start miles and have never been this slow a rate. One woudl think that once the batteries are "warm" (what ever that temperature is?) then the rate of charge should not be impacted by the outside environment temperature. On the flip side, if I am in the southwest and have a few days of +100 F does that mean the charging rate will be reduced because the batteries may get too hot? Is there an optimal temperature range for battery charging? i.e. Goldilocks not to hot and not to cold.

 

[rypalmer]

on all 3 days I stayed plugged in for at least 1 hour and the charge rate never improved.

You might be suffering from an issue I encountered last weekend: Use L2 charger instead of Supercharger when battery is cold with very low SoC

If you have the chance, try plugging into a L2 charger first, and see if that warms the pack effectively first, and report back.

 

[Larry]

The SpC is close to a Starbucks and other restaurants that I frequent so it is easy to just plug in and get a full charge when I am out an about. However I do not see how 15-20 F temperature should cause such a significant drop in SpC performance. The charging rate is less than home charging. If this is truly the case of battery protection then how does anyone in Canada when the temperature gets to negative degees F charge?

Better yet charge at home prior to leaving and the battery will be warm. Superchargers should not be used for locals to charge. See multiple threads about this please.

 

[Rocky_H]

Another thing was the estimated time to full charge was 40 minutes (on the 6th with 100 miles to go and at 12 mi/hr (4kW)), 50 minutes (on the 7th with 140 miles to go at 38 mi/hr (11kW)), and 50 minutes (on the 8th with 150 miles to go at 2 mi/hr (0-1 kW). The same information is on the Tesla phone app which shows amps instead of kW (the car used to show volts and amps but it seems the latest update changed it to useless kW.

First off, it's a little humorous to see you refer to kilowatts as "useless", since the rate that the battery refills scales exactly with the power in kilowatts, rather than either volts or amps by itself. So to know if a charge rate is sensible or not, you really do need to check kilowatts.

Anyway, there's not something wrong with your car. This is an effect of the battery being cold and needing to heat up some before ramping up the charging rate. You're overlooking something in your data.
100 miles to go at 12 mi/hr (4kW): That would be 8.3 hours, but the car says 40 minutes

140 miles to go at 38mi/hr (11kW): That would be 3.6 hours, but the car says 50 minutes

150 miles to go at 2mi/hr (0-1kW): That would be 75 hours, but the car says 50 minutes.

Notice how the estimated completion time knows (and tells you) that the rate is currently low, but will be rising up to much higher levels later, so it will take a reasonable total time--not 3 or 8 or 75 hours?

Also, not your fault because this is confusing, but the volts, amps, and kilowatts rates are all realtime instant readings, but the miles/hr reading is a hand-waving average through the duration of the charging session. So if a charging rate is starting off slow and rising up to higher rates later, that miles/hr number is going to look kind of low.

 

[brucet999]

I charged at Fountain Valley yesterday morning at SOC 15% and battery temp of 20ºC (68ºF). Initial charge rate as only user on station pairs was 48kW. Tesla support told me that charge rate is limited when battery temp is 20ºC or lower. Sure enough, the rate increased after a few minutes, but never to the expected 90+ kW, only to 66 kW, then gradually dropped to 30 kW as SOC got into the taper zone.

 

[dgpcolorado]

Did you, by any chance, have Range Mode on? Just wondering.

 

[APD1080]

After months of my efforts bugging Tesla support/engineering Tesla finally determined (in January) we had 1st a bad battery coolant pump. After that was replaced there was some improvement on the charge rate and battery temperature but not back to what we experienced when we picked up the car. Not happy I continued my quest and in March Tesla determined I had a bad fuse box. It was replaced and an AMAZING thing happened...the charge rates improve dramatically, back to what we had initially experienced (20+ mi/hr) and battery temperature issue has disappeared. I appreciate everyone's thoughts on why we were experiencing the charging difficulties the bottom line the car and battery shoudl perform as designed and anything less is unacceptable. Tesla needs to improve how the work with their owners when it comes to technical issues as we know our car better than Tesla engineers do. We drive it everyday and learn the car and know when something has changed our is not right.