Slow supercharging in hot weather?

[jkliu47]

Apacheguy : similar experience here in Cabazon (on the way to Santa Fe). Charged this afternoon in 110F temps. Started at 116 kW then quickly dropped to ~60kW within 10 minutes. No one else was sharing my charging, but its still relatively crowded - 50% of stalls were occupied.
Fortunately this doesn't change my trip scheduling since the wife is shopping at the outlet shops.

 

[rypalmer]

Apacheguy : similar experience here in Cabazon (on the way to Santa Fe). Charged this afternoon in 110F temps. Started at 116 kW then quickly dropped to ~60kW within 10 minutes. No one else was sharing my charging, but its still relatively crowded - 50% of stalls were occupied.
Fortunately this doesn't change my trip scheduling since the wife is shopping at the outlet shops.

Encountered this in Toronto this evening. Exact scenario. It wasn't really that warm - perhaps 25°.

 

[ThosEM]

Definitely not full proof. I'm at Harris and there is absolutely no indication on my screen that the SpC is throttling. Very frustrating.

Would it really make you feel any better to have an icon that confirms what your charging display is already telling you? I suppose it at least provides an explanation other than malfunction, but that doesn't impress me much...

 

[apacheguy]

Would it really make you feel any better to have an icon that confirms what your charging display is already telling you? I suppose it at least provides an explanation other than malfunction, but that doesn't impress me much...

If I could've known ahead of time I probably would have selected another route.

 

[twonius]

i experienced this at buttonwillow several days ago. The logic of slowing down your charge rate does not affect the amount of power used. Each car will just stay longer and overlap the charging of other cars still using the same amount of power. No peak limiting will occur. It was very inconvenient to have to stay an additional 20+ min to charge. I even moved on to the Tejohn charger (the ones with batteries) and the restricted charge levels were still in effect. I rerouted to the buttonwillow charger since the map indicated the Tejohn charger was operating at reduced capacity (coming down the 99). The map did not indicate reduced capacity at Buttonwillow. So that added additional delay. I was the only person at both chargers. Very annoying .

Same thing happened to me at about 6pm on August 6th. We were only able to charge at about 40kW (hello Chademo)

I figured it was some kind of curtailment since it was about 103F at 6pm.

Although as I recall the pack needs to be cooled as well during supercharging so this this may be a limitation of the car itself. Maybe we'll need to start doing retrofits like the turbo people do and add water sprayers to the radiators

 

[Tdriver]

Looking at this from another angle, many utilities are doing away with net metering so fewer solar panels will be sold and their profits hold. This does nothing to improve the demand on the grid so look for these restrictions to continue every summer.

 

[ThosEM]

I'm in full denial that this could be acceptable. Really, it amounts to fuel rationing. We have further to go than I thought before EVs are ready for long distance travel. Tesla or someone is going to have to make good on the use of batteries to buffer and release energy when needed, or this isn't going to make anyone switch from ICE, and it certainly isn't going to realize the potential for leveling the load on the grid.

 

[apacheguy]

Agree. This is something I already discussed with potential Tesla buyers over the weekend since it affected our travel plans. They were less than enthused to hear that charge rates are severely impacted by weather conditions.

 

[AMPd]

At Harris Ranch now. Started out fine at 114 kW and held for about 60 s. Then it started tanking fast. Now only getting 58 kW. Is this consistent with others experiencing PGE throttling?

Experienced the same thing at Harris ranch a week ago.
I was there around 9-10 pm.
Started out normally then tapered down to 150+ amps and held there until I left.

 

[ThosEM]

I posted this on the Tesla forum also, and someone there claims to have talked with someone at Tesla, and was told that "this is a known issue with some of the newer technology supercharger setups, and is being investigated". The implication is that this is an anomaly and not a new normal, so perhaps I'm extrapolating too far here. The short term workaround is reportedly to switch to another bay. That did work for us at Hamilton Marketplace, once, but appeared to be temporary. How can we get a definitive answer on this from Tesla?

 

[gavine]

Sorry, but this is flat-out incorrect. The biggest problem is that you are using units terms incorrectly. Normally, I won't be a stickler about using terminology wrong, but that's why you're not getting it right in this case. @thecloud also gave a correct explanation on this.

Power is a term that means a rate per second that energy is being used or moved. Watt is the usual term for that (or kilowatt). A Watt is 1 Joule per second. Energy is a different quantity. Energy may be measured in Joules, or as you are more familiar with, kilowatt hours. Notice that you take the power, which is energy per second, and multiply it by the amount of time to get the amount of energy. When you said, "Each car will just stay longer and overlap the charging of other cars still using the same amount of power.", that is not right. You mean the same amount of energy.

So anyway, these peak demand charges that the utilities have to deal with aren't about the total amount of energy. They are about the fastest rate that they are having to deliver it. And slowing down the rate at the Superchargers definitely does reduce those peak power levels.

If I had a penny for every time someone said kilowatt-hours instead of kilowatts.....that's like equating gallons of gas to horsepower.

 

[ThosEM]

I have now consulted with Tesla Roadside Assistance and learned the following:

• There are a number of stalls in any number of superchargers that are flagged for poor performance for various reasons, at any given moment.
• The information about which stalls are bad is not made available to travelers in any way except for them to call Roadside Assistance and get the info that way.
• We are invited to call for each supercharger we approach to get this information.
• Tesla is doing the best it can to keep things running smoothly. In some cases this may involve repairs of the equipment or relations with specific utility companies. Whatever that means...

Bottom line: I'm not going to take my Model S to Maine this year, after doing so 3-4 times previously, because there is no assurance the trip will not be hugely prolonged by difficulties with the superchargers that gave me troubles this past weekend.

IMHO, this problem is an existential threat and a crisis for Tesla. If these expensive cars are found to be incapable of long distance travel (in hot weather or other specific common conditions) it's game over. A short term solution would be to get the stall condition information into the NAV system so drivers can see what they are facing at each supercharger. The longer term solution is perhaps not practical, because it involves placing batteries larger than those found in the cars at each supercharger to accumulate energy and release it at high rates as demanded by travelers. Of course that might even suggest use of solar cells to charge the batteries, as was once advertised by Tesla.

 

[ArtInCT]

ThosEM, I was recently up to Maine, stopping at the Milford, CT, Auburn, MA, Seabrook, NH and Augusta, ME superchargers. They were all essentially empty of traffic and icing and each provided 290+ Amps and 350V+ at initial hookup. Running smooth. I think you can trip up that way with some amount of confidence.

 

[ThosEM]

ThosEM, I was recently up to Maine, stopping at the Milford, CT, Auburn, MA, Seabrook, NH and Augusta, ME superchargers. They were all essentially empty of traffic and icing and each provided 290+ Amps and 350V+ at initial hookup. Running smooth. I think you can trip up that way with some amount of confidence.

How hot was the weather when you traveled? Maybe I just have to get through NJ?

 

[thecloud]

Well, it's not the rate at initial hookup that folks are reporting as the problem, but the fact that it proceeds to drop down to about half of that initial rate, turning a 30 minute supercharger stop into a hour.

But even if that's the case temporarily while Tesla gets it resolved, I think it's hyperbole to say it renders the car "incapable of long distance travel." Any temporary inconvenience we experience causes us to scream about Tesla's continued viability, but there was no decline in sales last year after the 2-hour wait at the Tejon Ranch supercharger got publicized. (That got fixed by opening another supercharger up the road.)

I think ThosEM's ideas are good ones: if we could see real-time stall utilization information and per-stall status in the Nav system, we could make a more informed decision about what route to take. (Chargepoint can do this in their app for L2 chargers, so it's certainly possible.) And why don't more superchargers have solar-cell canopies and battery storage? Has it been proven impractical by Tejon and Barstow, perhaps?

 

[ThosEM]

I don't mean to be apocalyptic, but if my experience last weekend was endemic in hot weather, it would amount to a level of energy rationing that has not been seen since the oil crisis days when we would be faced with long line waits to get fueled up. I can assure you that I am going to have an uphill battle to persuade my spouse to try a long trip again after this bad experience.

We've all encountered long gas lines in certain limited times and places, but the understanding is that such is to be endured and will go away. Even if Tesla and others build a lot more fast charging points, and even if they keep them working well and inform us when there are localized outages, a pervasive spectre of utilities shutting them down in hot weather over wide regions, to preserve their grid integrity, is going to cast a pall over this technology. I hope Tesla has a plan for addressing this. I'm sure we are all subject to notifications of "gold days" when the weather gets hot, soliciting us to shut off all unnecessary power use. Our utility company pays us to save power at home on such days. It's easy to foresee a collision between legions of new Model 3 owners (and other EVs) and the utility companies in coming years. That isn't going to work itself out naturally.

 

[TexasEV]

I don't mean to be apocalyptic, but if my experience last weekend was endemic in hot weather, it would amount to a level of energy rationing that has not been seen since the oil crisis days when we would be faced with long line waits to get fueled up. I can assure you that I am going to have an uphill battle to persuade my spouse to try a long trip again after this bad experience.

We've all encountered long gas lines in certain limited times and places, but the understanding is that such is to be endured and will go away. Even if Tesla and others build a lot more fast charging points, and even if they keep them working well and inform us when there are localized outages, a pervasive spectre of utilities shutting them down in hot weather over wide regions, to preserve their grid integrity, is going to cast a pall over this technology. I hope Tesla has a plan for addressing this. I'm sure we are all subject to notifications of "gold days" when the weather gets hot, soliciting us to shut off all unnecessary power use. Our utility company pays us to save power at home on such days. It's easy to foresee a collision between legions of new Model 3 owners (and other EVs) and the utility companies in coming years. That isn't going to work itself out naturally.

I think your concern is overblown. Tesla is having maintenance issues with some supercharger stalls. It will be fixed. Chill.

 

[ArtInCT]

How hot was the weather when you traveled? Maybe I just have to get through NJ?

It was about 10 degrees cooler up there vs here in CT, high 70's to low 80's.
I did notice in Seabrook, NH, that as my battery became hotter after about 12 minutes on the SuperCharger that my fans on the car kicked in and the charge amperage did lower as a result (but the voltage kept climbing slowly). When the fans turned off the amperage went up again. This appears to be typical behavior on my car. I think that the car's battery pack and controller must signal the SuperCharger to back off a tad. But I was charged to 90% within 40 minutes. By the time my wife walked to the restroom area and back and I did the same (also got a coffee) well the car was charged.

In Seabrook NH, a Penara is right across from the SuperCharger and in Augusta, there are a few restaurants within walking distance. In all three locations, the chances of being Iced are almost impossible as the SuperChargers are no where near heavy traffic locations but are out of the way so to speak.

In Augusta ME, a large group of Harley riders came over to see the Tesla and talk about it with us. (probably there to see my wife actually). They were really interested in the car and asked some great questions. I have always found cycle riders to be friendly, knowledgeable, (as well as seeking knowledge) and very down to earth folks.

I had the HVAC off on the car while at the SuperChargers, so the fans came on to cool down the traction battery during the recharge sessions, I recon.

I hope this information helps you amigo.

 

[apacheguy]

The battery generally does not get hot enough while SpC that it would decrease your charge rate appreciably. Even when the fans first come on, the battery is still passively cooling. Only when it gets up to 50 C does the chiller/compressor come online. The battery generally cools quickly with the chiller on.

 

[ThosEM]

Thanks all for your perspectives. ArtinCT, my car behaves the same way normally, lots of AC noise in hot weather even when the cabin AC is inactive. In last weekend's case, though, the charge rate was pitiful. If the AC system were inoperative, I could understand this, but that's clearly not the case.

Today I'm heading for Maine from Annapolis in the afternoon, with fingers crossed that I get through NJ into New England with a single stop at either E Brunswick or Edison. One additional stop at W. Hartford or Auburn should do it for normal conditions. I'll report back how it goes.