Large Drop in Charge When Parked in the Cold

[jerry33]

I've never seen a parking facility anywhere in the New Hampshire or Massachusetts area with a block heater plug and we get temperatures like that almost every winter.

My experience is in Canada and the Western U.S. Bad assumption on my part that the East would be similar for similar conditions.

If the car can't be left in cold temperatures for several days without being plugged in, fine, but Tesla should make that very clear.

Agreed. First we need to make sure it's just not a temperature inducted artifact on the display.

 

[Johan]

MikeK: I wish you luck with this and Merry Christmas!

 

[kendallpb]

I'm not a battery expert, but you may be able to calculate an approximate voltage sag based on temperature and translate that into a range compensation. I'm not looking for a pefect compensation, but something's better than nothing.

If nothing else, some kind of warning like "Battery cold--range estimate may be lower than actual range; range estimate will correct itself as the car warms up" or something, so folks know not to panic.

If this is the issue, I mean.

 

[DaveVa]

The important question here is if the car has actually consumed all those "miles" (kWh) during the cold night OR if range just seems depleted at first due to the battery being cold and the battery system due to this reads a lower voltage, maybe also changes in impedance etc. which makes it think that the SOC is lower than it is/will be read once the battery comes up to proper operating temperature.

After 20 or so miles my rated range gained about 15 miles (80 to 95). I don't know if it would have gained more than that, because I was able to plug in at that point.

 

[dennis]

Tesla's plug it in every night has that kind of meaning.

Correct me if I am wrong, but doesn't the Model S only initiate charging when you plug it in and terminate charging once the battery has reached the requested capacity? If you leave the car plugged in and go away for an extended period, what will cause the car to re-initiate charging to replenish the charge lost to conditioning the battery?

 

[MikeK]

I've been told that the car will use "shore power" to keep itself topped up and to keep the battery within operating temporary ranges.

 

[Larry Chanin]

I had V4.0 software an went to friends house. Arrived with 145 miles rated range. When leaving 16 hours later range had dropped to 102 miles rated range. Car was uncovered in the driveway overnight with cold temperatures and high winds. I have sleep mode enabled - so this is not the normal "vampire load" issue with the displays. It's just likely what the car needed to do to keep the batteries warm - both regen and power were limited in the morning.

I'm all for Tesla maximizing care of the battery pack, however it is important to communicate expected behavior. I could have plugged in to a 120v outlet at my destination, but didn't since 145 miles range was plenty to get home (100 was just enough).

Have others seen similar behavior? Will v4.1 be different?

Hi Dave,

I had a similar experience.

Two nights ago I parked my Model S overnight at a hotel without plugging in. It was cold for Florida, it dipped into the high 40's. I had 160 miles of rated range when I parked it and the next morning it displayed 130 miles. At the time I had the impression that regeneration was greatly reduced. That morning we drove just a few miles and then I went to a friend's home nearby to charge at a NEMA 14-50 outlet for an hour or so.

I didn't closely study the charging process, but I do recall noticing the range was now 140 miles, then just a short time later it was about 165 miles. I didn't check my watch during this process, but my impression was there wasn't sufficient time to add that much range at typical charging rates. I of course don't know, but I believe perhaps the heating of the battery during charging caused the car to recalculate range higher rather than charging actually adding that much more energy.

I had version 4.0 of the software at the time and I had the "KEEP DISPLAYS POWERD" feature in the OFF position.

I reported this behavior to our local service manager and he said he was opening up an engineering case.

Larry

 

[PRJIM]

My Model S is parked in the dead of winter at the Buffalo-Niagara Airport for the next 7 days. Fingers crossed.

 

[jerry33]

Correct me if I am wrong, but doesn't the Model S only initiate charging when you plug it in and terminate charging once the battery has reached the requested capacity? If you leave the car plugged in and go away for an extended period, what will cause the car to re-initiate charging to replenish the charge lost to conditioning the battery?

My understanding is that it will occasionally restart the charge to keep the battery topped up (assuming standard charge). I think it's only once a day or some similar interval.

 

[Jaff]

Dave, unfortunately you have learned the hard way...first rule of cold weather "EVing" is "if you can plug in, even if it's only to keep your pack warm, do it".

I drive my Roadster all year round...my trip house to office is about 3 kms...I installed a 110 volt plug behind my office for the express purpose of keeping my pack warm...only takes a minute to plug in, so, if you can plug in, there's no reason not to do it...

 

[Larry Chanin]

My understanding is that it will occasionally restart the charge to keep the battery topped up (assuming standard charge). I think it's only once a day or some similar interval.

Unless there is something specifically amiss with my car, topping off occurs much more frequently than daily. I'm guessing its probably at least hourly.

Larry

 

[dennis]

Unless there is something specifically amiss with my car, topping off occurs much more frequently than daily. I'm guessing its probably at least hourly.

Larry

I don't believe that is happening with my Model S. Since 4.X has not yet downloaded, I am still losing 10 miles/day. My charging usually completes around midnight, and when I unplug the next day, the indicated range varies, but is always less than that of a standard charge. And the later I unplug, the less range I have. That is what prompted my query.

 

[PRJIM]

I don't believe that is happening with my Model S. Since 4.X has not yet downloaded, I am still losing 10 miles/day. My charging usually completes around midnight, and when I unplug the next day, the indicated range varies, but is always less than that of a standard charge. And the later I unplug, the less range I have. That is what prompted my query.

If the vehicle is plugged in for 5 days the amount of usable range is reduced by 30-40 miles. If you were to check on the range after an overnight charge, the range should be- I am guessing- between 220-240 miles. The longevity of the battery is tied to the SOC. The optimal usable SOC is 40-60%. This is probably the reason your car is bleeding miles.

 

[montgom626]

If the vehicle is plugged in for 5 days the amount of usable range is reduced by 30-40 miles.

I am unclear why a plugged in MS would lose charge?

 

[mdh]

this topic is rather concerning... I hope someone gets a response from TM.

 

[dennis]

If the vehicle is plugged in for 5 days the amount of usable range is reduced by 30-40 miles. If you were to check on the range after an overnight charge, the range should be- I am guessing- between 220-240 miles. The longevity of the battery is tied to the SOC. The optimal usable SOC is 40-60%. This is probably the reason your car is bleeding miles.

I believe my car is bleeding 10 miles per day because it is keeping the displays powered since I don't have 4.X. That said, assuming a standard charge (240 miles), at what point of bleed-off should I expect the system to re-initiate charging of the battery, assuming the car has been plugged in continuously because I am away on vacation?

 

[montgom626]

Have we gone off topic??

Have we gone off topic??

The title of the thread is

Large Drop in Charge When Parked Unplugged in the Cold

Now we have moved to

Large Drop in Charge When Parked plugged in the Cold??????????

 

[dennis]

I don't think we are off topic. The question I posed was whether keeping the car plugged in would in fact keep the battery charged, since I haven't seen that happen with my Model S.

 

[PRJIM]

I believe my car is bleeding 10 miles per day because it is keeping the displays powered since I don't have 4.X. That said, assuming a standard charge (240 miles), at what point of bleed-off should I expect the system to re-initiate charging of the battery, assuming the car has been plugged in continuously because I am away on vacation?

I believe the car will try to keep the SOC in the 60% range. This would be the equivalent of "storage mode" that is present in the Roadster. I have 4.0 and my vehicle still loses at least 7 miles a day when plugged in. Are you on 1.15.4?

 

[dennis]

I believe the car will try to keep the SOC in the 60% range. This would be the equivalent of "storage mode" that is present in the Roadster. I have 4.0 and my vehicle still loses at least 7 miles a day when plugged in. Are you on 1.15.4?

I am on 1.15.14. My car was delivered on 10/30, and neither the Menlo Park service manager nor Ownership have been able to determine why I haven't received the 4.0 upgrade.

Do you have any guess on what 60% SOC represents in terms of "ideal" range?