Supercharger - Oakhurst, CA (LIVE Feb 2022, 8 V3 stalls)

[willigetit]

Has anyone charged here successfully in the last week since the Washburn fire ?

Thank you

 

[ucmndd]

Has anyone charged here successfully in the last week since the Washburn fire ?

Thank you

There are no impacts or closures from the Washburn fire in Oakhurst proper.

 

[tivoboy]

Charged here last week Thursday, SOC 15% had 250+ for up to 30% and then 150% for up to about 50% SOC.. tried again on Sunday at 20% SOC, couldn’t get more than 50 kWh at THREE different chargers.. do they throttle power on weekend or at various times? At the time I was there, no other users were charging at about 09:45 AM. I should have just charged back up at Fish Camp where I had 125-150 most times.

 

[ucmndd]

do they throttle power on weekend or at various times?

No. Was your battery cold?

 

[Dave EV]

No. Was your battery cold?

This is the most likely explanation - gets cold around there at night.

 

[tivoboy]

No. Was your battery cold?

Well, it had done pre-conditioning for 25 minutes prior to arrival, and was at 12% SOC at arrival. When I arrived there was one other Tesla, after I moved three times I asked them if they had trouble getting power and they were getting 50 kWh but at higher SOC at the time.

 

[ucmndd]

Well, it had done pre-conditioning for 25 minutes prior to arrival

Honestly that’s not nearly enough time for a fully cold battery that has been sitting all night.

You make a good point though for people staying in Oakhurst. If you have enough range to make it up to Fish Camp on your way to the park, you should absolutely charge there vs. Oakhurst. Particularly if your car has been sitting all night. The 600-700 wh/mi you burn to get up the hill will heat the battery much more effectively than preconditioning.

 

[STS-134]

Honestly that’s not nearly enough time for a fully cold battery that has been sitting all night.

You make a good point though for people staying in Oakhurst. If you have enough range to make it up to Fish Camp on your way to the park, you should absolutely charge there vs. Oakhurst. Particularly if your car has been sitting all night. The 600-700 wh/mi you burn to get up the hill will heat the battery much more effectively than preconditioning.

I doubt that. Isn't the preconditioning system dumping about 6-8 kW worth of heat into the battery when it's running?

 

[tivoboy]

Honestly that’s not nearly enough time for a fully cold battery that has been sitting all night.

You make a good point though for people staying in Oakhurst. If you have enough range to make it up to Fish Camp on your way to the park, you should absolutely charge there vs. Oakhurst. Particularly if your car has been sitting all night. The 600-700 wh/mi you burn to get up the hill will heat the battery much more effectively than preconditioning.

You really think 25 min of driving pre-conditioning and 15 minutes of actually charging wouldn’t be enough to bring battery temp high enough to get more than 45-50 kWh at a Version 3 SC?

 

[ucmndd]

I doubt that. Isn't the preconditioning system dumping about 6-8 kW worth of heat into the battery when it's running?

Depends on the config of the specific car of course, but from what I’ve seen the resistive heating elements use about 4-5kw at full tilt. So yeah, practically speaking I don’t think that’s enough time to get a ~1200 pound battery in the 40s/50s to north of 110 degrees where modern firmwares want the cells to be for max charging rate.

 

[ucmndd]

You really think 25 min of driving pre-conditioning and 15 minutes of actually charging wouldn’t be enough to bring battery temp high enough to get more than 45-50 kWh at a Version 3 SC?

Where were you driving from for those 25 minutes?

Of course it’s “possible” the station was having issues. That said, I’ve charged there probably 75 times at this point, at all times of the day and night, and never had an anomalous experience. It’s getting cold here in the mornings. It’s my experience most people vastly overestimate the effect of preconditioning. So…

 

[STS-134]

Depends on the config of the specific car of course, but from what I’ve seen the resistive heating elements use about 4-5kw at full tilt. So yeah, practically speaking I don’t think that’s enough time to get a ~1200 pound battery in the 40s/50s to north of 110 degrees where modern firmwares want the cells to be for max charging rate.

I don't think these cars use resistive heaters. They either run the motors inefficiently or use the compressor or heat pump or some combination of the above.

 

[tivoboy]

Where were you driving from for those 25 minutes?

Of course it’s “possible” the station was having issues. That said, I’ve charged there probably 75 times at this point, at all times of the day and night, and never had an anomalous experience. It’s getting cold here in the mornings. It’s my experience most people vastly overestimate the effect of preconditioning. So…

Yes, was driving the entire time, maybe 3 min sitting. Just south of the main gate.
The Thursday prior I was there, had 250+ for up to nearly 30% SOC.

 

[ucmndd]

I don't think these cars use resistive heaters. They either run the motors inefficiently or use the compressor or heat pump or some combination of the above.

So again, what you mean by "these cars" is relevant. My 2016 Model S most definitely uses a resistive heater. As do early Model Ys and Model 3s before ~2020.

That's best case for preconditioning... the heat pump and/or waste heat from the motors is going to produce far far less.

 

[ucmndd]

Yes, was driving the entire time, maybe 3 min sitting. Just south of the main gate.
The Thursday prior I was there, had 250+ for up to nearly 30% SOC.

So you were driving down SR41 south into Oakhurst on a cool morning?

That's basically coasting, not drawing any significant energy from the battery for propulsion... nothing that would heat the battery in any significant way. In fact my wh/mi is usually negative between Fish Camp and Oakhurst.

What year/model/config car do you have?

 

[STS-134]

So again, what you mean by "these cars" is relevant. My 2016 Model S most definitely uses a resistive heater. As do early Model Ys and Model 3s before ~2020.

It uses a resistive heater to heat the cabin. The superbottle system uses only the motors to heat the batteries. There's no way to get heat from the PTC heater to go to the batteries.

That's best case for preconditioning... the heat pump and/or waste heat from the motors is going to produce far far less.

Not really. It's not "waste heat" from the motors as much as it is INTENTIONAL heat. It intentionally "stalls" the motor to overheat the stators and then uses the coolant to remove the heat that it (intentionally) created and deliver it to the battery. Bjørn saw the stators reach 55°C with the car sitting still.

 

[Dave EV]

So you were driving down SR41 south into Oakhurst on a cool morning?

That's basically coasting, not drawing any significant energy from the battery for propulsion... nothing that would heat the battery in any significant way. In fact my wh/mi is usually negative between Fish Camp and Oakhurst.

What year/model/config car do you have?

I have all the same questions - especially the specific car you have.

I assume that on Thursday you were driving into Yosemite and had been driving for a few hours and charged before heading to the park. Battery would have been nice and warm by that point, for sure.

Then you did a bit of driving spread out over a few days in temps from ~40-50F during the day and around freezing at night. The battery was likely cold soaked after sitting all night and near freezing.

Then ~30 min of driving on the way to the Supercharger (just to confirm, you had the Supercharger set as your destination and the car said it was pre-conditioning for Supercharging in the nav?).

Maybe the battery got back up to 50F? That's way too cold for fast Supercharging. Even 60-70F is cold enough to significantly throttle Supercharger speeds.

I really do wish the car would tell you what is the current limiting factors on charge speed, whether it's temperature, SOC and/or Supercharger so one can better identify if it's worth trying different posts or not.

 

[ucmndd]

It uses a resistive heater to heat the cabin. The superbottle system uses only the motors to heat the batteries. There's no way to get heat from the PTC heater to go to the batteries.

This is true for the 3/Y, but S/X prior to 2021 have a dedicated battery coolant heater. So again... details matter here.

See section 2 of this post:

Using Tesla thermal management system parts - EVcreate

Use Tesla parts in your electric car conversion to reduce costs and increase quality. Learn how to reuse Tesla thermal management system parts in your build.

www.evcreate.nl

 

[cpa]

In our 2014 S85 the battery does not warm sufficiently during the cooler months for a 35-minute drive to a Supercharger. I drive to Bakersfield and back several times during the year. When I leave home in late fall through early spring at 8:00 and arrive at Traver by 8:40-ish, the rate that I receive at 15% is around 70kW and dropping quickly once the preconditioning ceases. I dial into the Traver Supercharger upon departure.

On the return trip the ambient temps are higher, perhaps around 55. The 90-minute drive from Bako to Traver sufficiently warms the battery with minimal preconditioning so that the rate in the afternoon is closer to 90.

I think Tesla needs to be more candid about preconditioning so that we know why we are receiving a much lower initial charge rate.

 

[ucmndd]

Supercharging is hard.