Battery fan problem when supercharging

[goldenstop1]

I am having a problem with supercharging that I am hoping some of you might be able to enlighten me on.

I have a new long range model S. First super charge seemed fine. Cold day. Peak charge rate was 143 kW. But next super charge on a much warmer day was a problem. Peak rate was close to 140, but then it quickly decayed to about 60 kW. This happened a second time, and then I noticed I did not hear any fan noise. So I took it in for a service check, and they claimed that everything checked out OK and that the fan was working, although it was “very quiet”.

Well, on a hot night here three nights ago I tried again. Now it peaked at 117, and again quickly decayed to 60. No fan. But wait! Then I noticed charge rate was climbing, and I heard fan noise! Rate climbed back to 80 and then slowly decayed as I would have expected for the charge level of the battery.

Questions:
1- has anybody experienced fan start delay?
2- the fan is very quiet, compared to my prior Model S. Is this normal for long-range Model S. Or might it be too slow?
3- is the charge-rate decay caused by battery management control sensing overheat, or just battery physics when battery is hot?
4- has battery potentially been damaged?
5- What did I forget to mention or ask? See graphs below of last charging session from “Stats” app.

Earliest available service appointment is set for 10 days from now...

 

[Electric700]

Is yours the Model S Long Range Plus? I know new ones support up to 225 KW at Supercharger centers that are V3+. To reach 50% from less than a 10% SOC, the owner in the video below found it took about 11 minutes on a V3 Supercharger (for normal use and better battery life, charge to 80 - 90%).

You can also hear the fans in the video. Of course the S and 3 are different, but may be the fan sound will help you compare.

The Supercharger center you visited might have had an issue too. It's best for Tesla to check your car's logs so they can compare with the ideal case for fastest charging based on what your car supports. They can check the Supercharger center and connector status as well.

 

[Silicon Desert]

Hmmmm that second graphic is telling you most of what you need to know. As the state of charge gets toward the upper end, then the charge is going to lower. In your case it looks like it occurred around 70%. I would have expected it to not quickly drop until a higher percentage, yet as you probably know there are a whole LOT of variable to consider when supercharging.

 

[JustADude]

Do you recall if there was anyone next to you when charging?

Only the new chargers don't share current with their neighbor stall.

If there was someone next to you charging there and was a v2 charger then that could explain it.

Maybe if you give the address of the charger someone can tell you if that is the case.

 

[Pettway]

Fast forward to today, and for roughly the last month I don't recall hearing my model 3 compressor run high anytime during supercharging. Last week I supercharged at 135-147 kW multiple times on a road trip without any noisy fan or compressor noise.

 

[Snowstorm]

I have a 2017 model S, and the ac compressor definitely goes to max on a hot day when supercharging, sounds like a jet engine. Maybe things got quieter on newer models?

 

[joninurmimetsa]

P85D here and it seems my heat exchanger fan/AC compressor are driven by cabin AC setting. If cabin AC is off, the HE fan and compressor immediately go to 100% duty cycle upon plugging in to SuC. If cabin AC is on, it seems to be in control of the HE fan and compressor and the speed/DC is markedly lower and to some extent based on what the cabin AC settings require.

This is especially noticeable if I turn cabin AC on while supercharging. It will immediately cause HE fan and compressor to ramp down to almost zero and only after a while slowly speed up again.

If it would be driven by actual battery cooling requirements during SuC, it would never ramp down from 100% duty cycle and cabin cooling would simply siphon whatever is needed from the bigger cooling loop.

All above is based on summer temperatures here in GA, so external temperature is easily high enough for the vehicle to use all cooling power it can muster.

Please note that this is 2015 (=older) model and control algorithm is probably different in FL vehicles.
For what it's worth, my car hasn't been hit by charge gate and I get full (adjusted) curve charging power.
-
JN

 

[Lasttoy]

Tesla told me not to run AC during super charging. It uses a lot of your charge. I was having super charging issues, pump 2 was bad.
The coolant system runs according to ambient and battery temp.

 

[AmpedRealtor]

Tesla told me not to run AC during super charging. It uses a lot of your charge. I was having super charging issues, pump 2 was bad.
The coolant system runs according to ambient and battery temp.

Whoever told you that is an idiot. If that were true you'd be losing tons of range when driving with the AC on. When I run AC during charging I've seen it take about 5 kW or less. Turning AC on or off makes no material impact on supercharging time.

 

[Rocky_H]

Whoever told you that is an idiot. If that were true you'd be losing tons of range when driving with the AC on. When I run AC during charging I've seen it take about 5 kW or less. Turning AC on or off makes no material impact on supercharging time.

You're not understanding what the issue is. It's not about the power usage. That would actually be way less than 5 kW. The A/C really is only about 1.5 to 2 kW or so. And you would be correct that removing 2 kW from the 100 or so kW incoming power would be insignificant.

The real effect is that if you are making the car try to divide cooling systems by trying to chill the cabin with the HVAC system, it is not able to use that exclusively to keep the battery cold during the charging process, which generates a lot of heat during high speed charging, and it can lower your Supercharger power by 10 or 20 kW or more to make sure the battery doesn't overheat so that you can also have A/C in the car.

I've seen the difference, so this is a real thing, and the person who informed about it is not "an idiot".

 

[goldenstop1]

Thanks for all the comments. The Tesla service folks are unable to reproduce my problem at their service center. Informally (wink-wink nudge-nudge) they agree that the data I provided shows incorrect charging rate behavior, but they don’t have a solution. In their tests, fan/cooling behaved correctly. They suggested trying a different Supercharger, which I have already done. I normally charge at home, but since it’s a new vehicle I tested Supercharging, expecting to get similar or better results than with my prior (90D), and discovered this issue. Now I’ve been doing Supercharging testing enough that I’m worried about running into the rumored(?) Supercharger rate throttling. I only have 2,000 miles logged so far but don’t know when that kicks in.

I will start taking 650 mile road trips from NJ to NC this fall so hope to get this resolved by then. Thanks for your interest.

 

[airborne spoon]

The real effect is that if you are making the car try to divide cooling systems by trying to chill the cabin with the HVAC system, it is not able to use that exclusively to keep the battery cold during the charging process, which generates a lot of heat during high speed charging, and it can lower your Supercharger power by 10 or 20 kW or more to make sure the battery doesn't overheat so that you can also have A/C in the car.

if the battery needs more cooling it will disable the cabin AC and push it only to the battery and the cabin will warm up since it's only recirculating old air.
When my louvers failed me a month or so ago if i supercharged the cabin AC wouldn't work until the next day because it was trying to cool the battery but wasn't getting airflow thus slowing the battery cooling down.
When i disconnected the power to the louvers and opened all 4 of them manually i could SC with the AC on and have no issue.
So basically you can have the cabin AC on while SC and have no issue with speed. But when the battery needs more cooling it will cut the AC. That happened a few times even when my louvers did work just because the outside air was 115-120F and it needed all the cooling it could get so the cabin AC stops and redirects itself to the battery.

 

[AmpedRealtor]

You're not understanding what the issue is. It's not about the power usage. That would actually be way less than 5 kW. The A/C really is only about 1.5 to 2 kW or so. And you would be correct that removing 2 kW from the 100 or so kW incoming power would be insignificant.

The real effect is that if you are making the car try to divide cooling systems by trying to chill the cabin with the HVAC system, it is not able to use that exclusively to keep the battery cold during the charging process, which generates a lot of heat during high speed charging, and it can lower your Supercharger power by 10 or 20 kW or more to make sure the battery doesn't overheat so that you can also have A/C in the car.

I've seen the difference, so this is a real thing, and the person who informed about it is not "an idiot".

I have supercharged with cabin cooling on and off. In my case there was zero difference in charge speed. The car's cooling systems are more than capable of handling peak supercharging while cooling the cabin. If it needs more cooling for the battery, it will reduce cabin cooling and throw an alert. Basic stuff.

 

[Rocky_H]

So basically you can have the cabin AC on while SC and have no issue with speed. But when the battery needs more cooling it will cut the AC. That happened a few times even when my louvers did work just because the outside air was 115-120F and it needed all the cooling it could get so the cabin AC stops and redirects itself to the battery.

I have supercharged with cabin cooling on and off. In my case there was zero difference in charge speed. The car's cooling systems are more than capable of handling peak supercharging while cooling the cabin. If it needs more cooling for the battery, it will reduce cabin cooling and throw an alert. Basic stuff.

Yes, those can also happen too in other conditions. I have heard plenty of people reporting that in extremely hot conditions, where it will totally stop the A/C from cooling the cabin for a while in favor of the battery. I am not denying that happens also. But there are times, as I described, where it will try to balance between both if it can, to give the driver the cooling they are demanding for themselves, while also trying to keep up some cooling for the battery, and it will reduce the charging power sometime to be able to maintain that balance when it can if it's not having to sacrifice too much from either.

Both cases do actually happen.

 

[TespaceX]

I know this is an old thread and unsure whether OP still has the car, but I’m in a similar situation and wanted to see if OP had found a solution.

I recently had a new replacement 90 battery, but since the replacement, my charging has been capped at 80kW (even at a V3). No fans ever come on now, whereas it did before with my original battery. And, Tesla tells me it’s normal. I’ve tried all the various resets with no luck.

 

[Lasttoy]

My car is an original built late 2012. I have 3 pumps, 3 diverter valve. Mine is a nightmare when u look at it. When I first got it, one day supercharging I though it was going too explode. Both front vents were open, all fans running. I called help desk. ,""Your car is too hot, max pack cooling is turned on"". My antique is gen 1 of everything, except I did Infotainment upgrade. My car charge goes down faster at night with lights and AC on. I have the HID lights , they take a lot of juice. I think Tesla has really improved this entire system. Like. I have no such thing as fast charging.