"Less energy is available due to cold battery" trying to charge

[Graffi]

LESSON TO BE LEARNED:

Stop at Supercharger for a high level charge prior to parking overnight in freezing temperatures. This way, even with a cold soaked battery you can start to drive which will warm up battery and cause the rated miles remaining to increase as you drive.

NEVER park overnight in freezing temperatures at a very low charge level. You my be spending a good portion of a day or more just trying to warm up the battery so you can start charging to get to the Supercharger. Imagine that you only have a L-1 or 120v outlet to plug into. In that case you will have to pay for a tow truck to carry you to the Supercharger.

 

[yobigd20]

Yet another example of 30A public L2 charging being woefully inadequate for cold climates.

had nothing to do with the amount of power on the charger. the car itself would not PULL more than 1A until it was over 10% SoC.

Do you know, why the car didn’t want to warm the battery? I understand, that it didn’t want to charge coald soaked battery, but why the car didn’t want to warm the battery?

no idea, and the Tesla guy on the phone just kept saying this is normal for a cold soaked battery until its back over 10%

What about actually charging the car and running the heater concurrently?

we tried this while Tesla was remotely connected and monitoring the car. the theory was that the cabin heater blasted at max would indirectly help warm the battery pack so it could get out of being in cold soaked state. unfortunately, having the cabin heater on had 0 effect on the battery temp, and we had it blasting for a long while. Having it on did *not* drain the battery at all either. Basically the battery pack was still being charged using only the same ~1A to trickle charge the battery pack while the rest 29A was being used for the cabin heater but having the cabin heater did not warm up the battery pack. For about an hour he was able to see an increase of charge state from 5.2% to 5.4%, while the temperature of the pack remained exactly the same with no increase.

This was user error

oh please, i'm an early adopter (VIN 05837) have had the car over 5 years and driven more than 163k miles on it. I've probably got more experience here with all the little quirks of this car than 99% of any other Tesla drivers, especially given the early build and all the fun stuff that none of you later models had to deal with. I have driven this car from 100% to 0-3% on countless occasions, in the freezing cold and in the summer heat. Never once have I had this happen. This 'cold-soaked' state is something new due to a software update, i'm just not sure which version they added this slower charging < 10%. It has to be fairly recent in the last year or so.

LESSON TO BE LEARNED:

Stop at Supercharger for a high level charge prior to parking overnight in freezing temperatures. This way, even with a cold soaked battery you can start to drive which will warm up battery and cause the rated miles remaining to increase as you drive.

NEVER park overnight in freezing temperatures at a very low charge level. You my be spending a good portion of a day or more just trying to warm up the battery so you can start charging to get to the Supercharger. Imagine that you only have a L-1 or 120v outlet to plug into. In that case you will have to pay for a tow truck to carry you to the Supercharger.

yea well that goes without saying. However an L1 or a 120V would have made no difference here, since it would still only charge at ~1A. and there was actually a 120V outlet at this location too, and we did try it. The result there was that instead of it pulling ~1A (it must have been between 1 and 2A because it would flicker back and forth but mostly stay on 1A), but on the 120V 15A outlet it would only pull ~2-3A, which from what the Tesla guy could see in the readings was charging the car almost exactly the same rate as it was when it was pulling 1A 240V from the L2 charger. So the outlet type/power available made no difference here.

Since i'm wayyyy past warranty, when the car shut down a few weeks ago it cost me $440 to tow it to the service center. Given that, I opted for the hotel room instead and keeping it plugged in for 10 more hours which only cost me $125. I'm cheap. well, that and the in-laws were visiting so there was no real good reason so race home any sooner haha

 

[AWDtsla]

No one mentioned this life hack (or has no idea), but if you are wedged for charging while parked at a charger:

1. Put it in drive.
2. Press the brake hard
3. Floor the throttle
4. Hold it for long enough to heat the pack.
5. Don't sue me if you crash.

You'll be dumping ~6-7kW of heat into pack coolant loop from the motor and inverter, in addition to the pack heater. Since you're at a charger, you won't worry about running the pack to empty. I've done this in traffic on the way to supercharger to dump ~11kW of heat into the pack while at a light.

 

[MP3Mike]

2. Press the brake hard
3. Floor the throttle

Does that really work? I thought you would get a "both pedals depressed" warning and the car doing nothing.

 

[AWDtsla]

Does that really work? I thought you would get a "both pedals depressed" warning and the car doing nothing.

You get the warning. But it still turns a bunch of battery energy into heat.

 

[hiroshiy]

I have one last question to @yobigd20 .

Maybe I missed something but you stated that the battery temp didn't change when you blast your cabin heater. That sounds strange to me and contrary to common knowledge. Did you turn off Range mode at that time of blasting? That is very important I think to redirect some of the cabin heat to the battery
.

 

[SSedan]

Sounds like with the battery at such a low state of charge the battery heater wouldn't run in any meaningful way.

Far as cabin heat it is not reasonable to think cabin heat will make it down into the battery in any large amount even if someone on the phone at Tesla said so, people answering the phone, aren't answering the phone because of their engineering skills. Internal resistance on the battery while running the heater will do more warming. Some might say same difference but I prefer to understand things not just accept them.

I believe the cabin and battery heat are completely separate systems, so there is not heat to "redirect".

 

[hacer]

oh please, i'm an early adopter (VIN 05837) have had the car over 5 years and driven more than 163k miles on it. I've probably got more experience here with all the little quirks of this car than 99% of any other Tesla drivers, especially given the early build and all the fun stuff that none of you later models had to deal with. I have driven this car from 100% to 0-3% on countless occasions, in the freezing cold and in the summer heat. Never once have I had this happen. This 'cold-soaked' state is something new due to a software update, i'm just not sure which version they added this slower charging < 10%. It has to be fairly recent in the last year or so.

All that experience and you're still reckless. By your own admission, you've run the car out of power; that's a rookie mistake as was parking in the cold for 2 days with a low battery.

 

[ucmndd]

had nothing to do with the amount of power on the charger. the car itself would not PULL more than 1A until it was over 10% SoC.

240V charging at 1A would take ~16 hours to raise an 85kwh battery from 5 to 10%. Was that really your experience?

 

[yobigd20]

240V charging at 1A would take ~16 hours to raise an 85kwh battery from 5 to 10%. Was that really your experience?

yep. from 6:30pm to 9am.

 

[yobigd20]

Does that really work? I thought you would get a "both pedals depressed" warning and the car doing nothing.

this doesn't do anything. yea you just get the error about having both pedals depressed.

 

[AWDtsla]

this doesn't do anything. yea you just get the error about having both pedals depressed.

Check your power draw.

 

[Brass Guy]

I imagine that might work with launch control, but I tried it with mine (a few years ago actually) and it did not draw that much power until after I lifted the brake. (Launching that way was actually slower than just stomping the accelerator.)

 

[AWDtsla]

I imagine that might work with launch control, but I tried it with mine (a few years ago actually) and it did not draw that much power until after I lifted the brake. (Launching that way was actually slower than just stomping the accelerator.)

I've defined "that much power" above.

You're basically doubling what you're getting out of the pack heater, for what that's worth.

 

[Brass Guy]

I've defined "that much power" above.

You're basically doubling what you're getting out of the pack heater, for what that's worth.

Agreed; I forgot the details of that post.

 

[jaguar36]

All that experience and you're still reckless. By your own admission, you've run the car out of power; that's a rookie mistake as was parking in the cold for 2 days with a low battery.

Running the car out of power with 8 miles remaining is not a rookie mistake at all. If anything its a mistake of to much experience. I've run the car down to below 8 miles a few times, always with the expectation that I have 8 rated miles of energy left, not 0.

Same with expecting the car to actually charge at a low power state. I've had a cold battery charge slowly before, but never 1 amp slowly. I agree that that is a new change and it doesn't make any sense why it wouldn't heat the pack.

 

[mspohr]

Thanks for the information and explanation from Tesla guy. I have seen reports of cold soaked and very low SOC battery, accepting very low current for charging. Last week I had like 6 degrees Celsius and about 0% battery left. There was a blue frozen sign on the dash. I connected to 64A HPWC and it started to charge at 64A from the beginning.
Maybe the temp is not that low in my case?

Also I wonder what would have happened if you had driven the car a few miles to warm the battery a little bit and charge.View attachment 279288

Bjorn has a video where he accelerates and slows down using regen to warm up the battery in a -17C car. Seems to be successful.

 

[rpo]

The issue here is that the car should be able to use shore power to run the battery heater. The fact that it is attempting to charge from 5% to 10% at only 1 amp is ridiculous. The only reason I can think of is the battery heater is not capable of varying its power consumption which could mean that it could pull more power than the outlet the OP was using and therefore *could* have drained the battery to 0 before warming the battery sufficiently to charge.

Thoughts?

 

[MP3Mike]

The issue here is that the car should be able to use shore power to run the battery heater. The fact that it is attempting to charge from 5% to 10% at only 1 amp is ridiculous. The only reason I can think of is the battery heater is not capable of varying its power consumption which could mean that it could pull more power than the outlet the OP was using and therefore *could* have drained the battery to 0 before warming the battery sufficiently to charge.

Thoughts?

I thought that the battery heater was 5kW. He was plugged in to a 30A outlet, which even at 207 volts should be 6.2kW. So that shouldn't have been the problem. But I wonder if you are on the right track, maybe Tesla has the cut-off at a 40A connection before it will allow the battery heater to turn on when the pack is cold-soaked at a low SoC. It sure would be great if Tesla shared these kind of details.

 

[rypalmer]

I've never had a L2 ramp that slow at low states of charge, and trust me I've been in that situation plenty. I've had pesky low states of charge when Supercharging but never while on L2 (this is a known bug, AFAIK). IMHO 29 amps were going to the battery heater, leaving virtually nothing to actually charge the car. Running the cabin heater would exasperate the issue. It reiterates my point that 30A L2 charging in cold climates is insufficient. One way to test this theory would be to cold soak the battery below 10% SoC, next to a 48A charger. I may try this sometime and report back.