Superchargers super-slow

[boaterva]

Interesting thread.... I've also seen Bjorn Nyland complain a lot recently about 'slow charging' in his treks all over the place from Oslo. That's definitely not local to his home, and not a USA issue. If the same 'phenomenon' is going on in Norway, it's an interesting data point.

He's been documenting it in a short video and is going to be contacting Tesla. That should be interesting for someone that has a free (more or less) car coming.

 

[boonedocks]

We are about to take our 2nd road trip ever in our 85D and my wife is already complaining that our last trip the supercharger stops were almost twice as long as quoted and we were alone at all stops. The slow SC really is a big deal.

 

[Ulmo]

It is a big deal. This is the first week I've gotten what seems like full SuperCharger speeds, even at places I used to get horrible speeds like Dublin and Fremont, and it is an entirely new experience. I used to think SuperCharging was a place to spend an hour doing nothing, but now with fast charging, the whole paradigm changes to just a fill up mentality like a gas station. It shortens trips tremendously, cutting out hours of extra travel and used up days.

At Fremont right now. Highest kW I've ever gotten. I had no idea it could even go more than 97kW.

 

[Ulmo]

So ... has anyone else also experienced this consistently good speed that I'm experiencing this week?

I charged at two more SuperChargers last night (Harris Ranch & Gustine), and both worked right, again. In both cases, it was deep night during off-peak and less than 3 other cars at both sites.

All of these successfully full speed charges happened during the new reign of the new CIO, and most of them during the remote app API outage. I don't know if those items are at all related.

Is this related to demand charges, electricity costs, etc.? All that hydroelectric power and wind power available, as well as solar power available, right now, might be causing lower prices? That's sure a wild guess on my part.

 

[WannabeOwner]

That should be interesting for someone that has a free (more or less) car coming.

Not sure if you were referring to Bjorn?

My understanding is that in Norway a Competition Prize such as a "Free Tesla Car" incurs a tax charge of 50% of the value of the prize So in Bjorn's case not exactly "more or less free"

 

[wdconnors]

I haven't read all of this thread, but I have never seen top kW charging in the Southeast if you are sharing a stall with someone (1A/1B/etc.).

If you're alone, you get 100kW, if you're sharing with one car, you get 50kW, and if you're sharing with three cars, each car gets about 30kW.

Obviously the time difference when not getting 100kW is a ton and that's the biggest pain point of being on a long trip.

 

[boaterva]

Not sure if you were referring to Bjorn?

My understanding is that in Norway a Competition Prize such as a "Free Tesla Car" incurs a tax charge of 50% of the value of the prize So in Bjorn's case not exactly "more or less free"

Yep, that was the 'more or less' free. Free car, then you have to pay all the tax on it. Even worse that in the USA. If it had been one of those sweepstakes like on HGTV where they give you money to pay some/most of the taxes, then it would be really free.

 

[TexasEV]

I haven't read all of this thread, but I have never seen top kW charging in the Southeast if you are sharing a stall with someone (1A/1B/etc.).

If you're alone, you get 100kW, if you're sharing with one car, you get 50kW, and if you're sharing with three cars, each car gets about 30kW.

Obviously the time difference when not getting 100kW is a ton and that's the biggest pain point of being on a long trip.

This thread is not about paired stalls. We're all aware of paired stalls. It's about superchargers supplying less power than they should when there is NOT a paired car.

By the way you only share with one car. Each supercharger cabinet supplies two stalls. If you were getting less kW than you should, it's unrelated to a third car charging, and is likely one of those slow supercharging sessions this thread is about.

 

[Ulmo]

... and two more good ones today, mid day, 30% full. So, I've experienced good charge speeds in multiple conditions this last week (dead of night, full during commute time, lunch-afternoon, etc.)

I'm liking using my Tesla the way it was meant to be used.

In every case, I also did Chademo charges along the way to reach the SuperCharger network (going in or out).

---

Edit: I spoke too soon. Alone, getting 40kW at 89% SOC, Harris Ranch. But still, it's better than 20kW at 30% SOC like I was getting last week in Gilroy when alone. It ramped down kinda steadily this time.

Yeah, I still think this is better than I was getting, on average.

 

[wdconnors]

Yeah, sorry I wasn't clear.

I am agreeing that there's likely an issue with implicit sharing because in the scenario I referenced, when car three drives away, charging goes up to 50 kW and then 100kW once you're by yourself. Based on everything we think we know, output should be full if you're not sharing an A/B stall.

 

[JClu]

Alone, getting 40kW at 89% SOC

40 kW at 89% SOC sounds pretty normal.

 

[Skotty]

I supercharge almost every week (I travel a lot for work). Some notes.

The best way to absolutely kill your charging rate is to leave your car out in the cold for a long period of time and then supercharge. I've done this numerous times, not really on purpose, but just out of circumstance, and a typical charging cycle is to start low, at about 20 - 40 kW, which increases up to about 60 to 70 kW max, then tapers back off near full back down to maybe 20 kW. This makes for a terrible charging experience. If you have to stay unplugged over a cold night, try to arrange to supercharge that evening rather than the next day.

On a good day with a low battery, I get up to about 110 kW when first plugging in, and that tapers pretty consistently over the charge down to maybe 20 kW near full. At roughly half charge, I'd say the typical charge rate is about 60 kW. Not great, but okay. I would like to see this improve in the future.

If you have a nav destination set, the car provides a nice feature of telling you how long you need to charge until you can continue the trip, and even sends alerts to the phone. This is nice, but I find the estimated time to be overly optimistic. However long it says you will need to charge, it will probably be longer.

I once ran into a charger that was only giving me about 50 kW even though battery charge was low, no other car was there, and the weather conditions were not a factor. I switched bays and started getting 90 kW. Not sure what the deal is, but apparently it's possible for a supercharger to under perform without being totally broke. This happened at a stall at the St. Louis/St. Charles, MO, supercharger maybe 6 months ago.

I once had supercharging fail shortly after starting. I unplugged, plugged into the same stall again, and then it worked fine the rest of the time I was there. So good to keep an eye on it just in case this should happen to you. Would suck to go somewhere for half an hour, get back, and find the car had stopped charging after the first 5 minutes.

I'm not convinced that the first person to start charging at a shared pair really gets priority. I have an anecdotal personal experience that brought this into question. I once proposed getting together with another Tesla owner for a day to run paired charging tests with our cars, but so far no one in my area has been willing to be that much of a geek, so I haven't had the opportunity to do thorough tests to prove it one way or the other.

Overall, supercharging makes long distance travel a reality, but it still needs to improve further in the future if EVs are to take over as the primary form of personal transportation. If it could manage 90 kW average for the entire charge required for the next leg of a trip, that would probably be sufficient. Whether that be accomplished by a higher max charge, bigger batteries allowing lower percentage charges and thus less taper, or improved battery chemistry that reduces required taper, any one or combination of those solutions would suffice.

 

[SeminoleFSU]

Not sure if you were referring to Bjorn?

My understanding is that in Norway a Competition Prize such as a "Free Tesla Car" incurs a tax charge of 50% of the value of the prize So in Bjorn's case not exactly "more or less free"

Gotta love government. But by all means, let's advocate for MOAR! SMH

 

[luckyj]

So ... has anyone else also experienced this consistently good speed that I'm experiencing this week?

Unless my battery was cold, I have yet to experience less than 100kW of power when my SOC was under ~64% and there was nobody on my pair. P100D owner for 3 months with 5k miles on the odometer. Have been to about 13 different superchargers over 800 miles distance across 5 states in the eastern mid-Atlantic area. I'm inclined to think folks who have trouble fall into a normal "slow charge" category. Like a cold battery (or a hot one). Or their SOC is > 70%. Or there is an equipment issue. Or other conditions folks have mentioned.

 

[trmmcd]

I just completed a road trip that included reuse of the same SC and fairly extreme temperature variation. In advance I added TeslaFi analytics to give me a more factual basis for my analysis. My big conclusion is that there really are a ton of variables that very significantly impact charging experience. While the SC maintenance issues are likely real, the more likely variations have to do with the complexities of weather, charge level and overall battery management.

While I collected a lot of data, the comparison that best highlights the issue was an outbound stop compared to the return stop at the exact same charger. The location was the Berlin VT SC which is very new and utilizes the new pull thru design.

On the outbound leg, I began with 99% battery from my home charger. I arrived at the Berlin stop with 12% remaining battery. I had a fantastic charging experience - 169 miles added in 39 minutes - for an effective charge rate of 4.3 miles per minute. The temperature was about 32F degrees.

Over the weekend - I had a bunch of shorter charges at S. Burlington. It was extremely cold 1F to 10F all weekend. I was eating miles quickly - about 50% efficiency overall.

On the return trip home - Tesla navigation had me stop at the same Berlin SC. A very different experience, but also lots of variables. I arrived at the stop having only driven 40 miles to get there. The temperature was much colder than my original visit - now at 10-15F. I used the exact same stall. I arrived with 60% battery. I left with a 90% charge, but it took 52 minutes with an effective charge rate of 1.79 miles per minute.

I have always know that the SC slows down as the charge progress - but this slow down was so dramatic I was surprised. Interestingly though - the Tesla navigation correctly predicted the required charge time at 50 minutes. The next trip - I will go out of my way to begin the return trip with a full charge. That is not always easy to do given the complexity of getting a charge at a destination - but likely worth the extra thought effort to avoid a necessary stop with a relatively high starting charge level.

Lastly, one of the SC's along the route was identified as having reduced service levels. I think this would have been a more natural stop than Berlin but I think the nav avoided it because of the reduced service status. I had never seen this before but was encouraged that Tesla incorporated this level of status reporting.

 

[boonedocks]

We just finished up a trip from Atlanta to Ocala FL, hopefully our last road trip in our 85D unless the EPA never releases our 100D :/, and the SuperChargers were far better than our last trip to Orlando in October '16. That trip all of our stops were by ourselves and no other Teslas present and were terribly slow never topping out over 50kWh AT ALL STOPS This trip same stops and we were getting 111kWh or better when charging first started AT ALL STOPS!!! I am not a conspiracy theorist but I do believe Tesla Corp has done something to kick the charging up between those two trips.

 

[trmmcd]

I just had a couple of great super charger stops - averaging over 4mi/minute gained - the best I have experienced in a while. I also had one very poor charge experience - called Tesla - and was told that that particular SC had intermittent issues and was scheduled for service.

I did recently see where Tesla has just submitted a patent for a safer charging method. I also seem to recall two relatively recent instances (last six months or so) of car fires at an SC. Did they perhaps change the SC algorithm while they investigated those fires?

Apart from the maintenance issue - which is clearly a problem - I now have more confidence in the effectiveness of SC stops. Hopefully that trend continues.

 

[AWDtsla]

Sounds like a software problem. I've seen the highest supercharging rates I've ever seen this weekend, so they've obviously been changing the code, because it used to be very ugly before. 292A from 13% to 42% (111kW) tapering slowly to 41kW at 79%.

 

[SomeJoe7777]

292A from 13% to 42% (111kW) tapering slowly to 41kW at 79%.

That's about right -- the way it's supposed to be.

Just as a rough guide, use the following thumb rule when at a supercharger to determine if your car is charging at the rate it should:

125 - [Current state of charge in %] ~= [Charge rate in kW]

Examples:

If you're at 15% state of charge, you should be getting around 125 - 15 = 110 kW.
If you're at 80% state of charge, you should be getting around 125 - 80 = 45 kW.

This thumb rule is roughly accurate to within about 5-10 kW in most of the state of charge range for 85 and 90 kWh batteries.

If it's off by a significant amount, something's wrong, try to change stalls.

 

[apacheguy]

You cannot apply this rule evenly to both 90 and 85 since these packs have a significantly different taper profile.