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Super Charger - Charge Rate?

Super Charger - Charge Rate?

I have tested Super Charging and I did not see anything near the published rates. One stall topped at around 40kw, another one tested topped at around 48kw and one of the last ones tested was topped out at 60kw. Car had just under 150 miles of charge left when tested. Does the vehicle have to be lower or are the chargers in my area just limited to 60kw Max? This was the location: https://www.tesla.com/findus/location/supercharger/tintonfallssupercharger

tes-s | 2 Janvier 2017

Yes. No.

martin | 2 Janvier 2017

It is winter. Which means it can be cold. And that means that the battery can be cold. If you put the energy app in the instrument cluster you can sometimes see yellow dots at the low and less often at the high end as well. That indicates that the battery is too cold to provide maximum power - both discharging and charging.
This has been discussed very often here in the forums...

martin | 2 Janvier 2017

And, yes, charging is faster when the battery is empty than when it is nearly full. From nearly empty (~10%) to nearly 70% will take roughly 30 minutes and the rest another half hour...

Bighorn | 2 Janvier 2017

*SOC + kW = 125 +/- 7

*may be reduced in cold weather

JayInJapan | 2 Janvier 2017

OP, have you read
http://teslatap.com/?s=owners+manual+companion ? It's highly recommended reading. Where's mclary when we need him?

djmichaelmayhem | 2 Janvier 2017

If you have a performance car, switch it to max battery power about 30 min before going to SuperCharge, that will help the process speed up a little in the winter, not a whole lot but a little.

djmichaelmayhem | 2 Janvier 2017

TeslaTap has some great info for sure!

Jaribbs | 2 Janvier 2017

My service manager also informed me that the SC is a stack of 6 chargers similar that in the car. So not only does a cold car battery slow charging but my service manager said a cold SC also leads to slower charging. The more frequently the SC is used keeps the chargers warmer and they charge vehicles faster. So there is a second side of the equation in the SC temperature to consider as well.

tes-s | 2 Janvier 2017

Your service manager is mistaken - which service center?

djmichaelmayhem | 2 Janvier 2017

@tes-s

I think @Jaribbs is understanding the info a little wrong.
As I understood, not newer, older superchargers use a stack of 12 10KW chargers and that power could be split between 2 cars (A-B Stalls).

In general, if you are plugging into 1A and someone is on 2A, your cars are sharing the charge rate. It gets a little more complicated than that because when you add in SOC, one car could be getting 80KW and the other 40KW.

When using a supercharger, look and make sure you are the only one on that number.... 1A, make sure 1B is vacant if possible. That will help your car get the max power for charging at that time minus variables...

djmichaelmayhem | 2 Janvier 2017

That should have read 1A and 1B
lol!

tes-s | 2 Janvier 2017

@mychol - I was referring to this statement: "my service manager said a cold SC also leads to slower charging"

I do not think that is accurate, based on my experience. Also, the charger is electroronics and it does not make sense it would be impacted by low temperatures. They have cooling fans - heat is a bigger issue.

Bighorn | 2 Janvier 2017

Everybody is partially correct but you're talking about different phenomena. The cold does seem to affect the supercharger rate based on the station being cold. Has nothing to do with either A/B pairing or the 12 stacked chargers.

tes-s | 2 Janvier 2017

ok, but then again I've never been to a supercharger when it was below 10F. Odd that electronics work slower in the cold, or that they would not be warm in seconds.

djmichaelmayhem | 2 Janvier 2017

@tes-s
Thank you for clearing that up.
As much as heat is the batteries enemy it is needed (right temperature range) to flow the electricity efficiently, the cold can effect the charge rate until the lines warm up but at the same time the cold will help reduce the amount of electricity we lose during the friction from the power transfer.

kinda damned if you do damed if you don't...

Bighorn | 2 Janvier 2017

It's not a big effect like having a cold battery. I just see about 10-15 kWs less than expected. There was talk of some stations having battery buffers on site which I could see being limited the same as the car battery, but I don't know if or where that has been implemented.

GHammer | 2 Janvier 2017

Also, the battery doesn't have to be very cold to slow charge rates. I charged at the empty Mountain View CA supercharger late at night after attending an all day event at the Shoreline Amphitheater and was only getting 50kW when my state of charge indicated I should have been getting at least 90kW. Temps were in the mid 50's but the car had been sitting all day (the supercharger is right outside the amphitheater). It took me a little bit to figure out what was going on, I even changed stalls. But sure enough, the charge rate eventually started going up as the battery warmed before I hit the natural taper again.

djmichaelmayhem | 2 Janvier 2017

@Bighorn
my point in going into the 12 Stack was @tommilone understanding of 6 chargers stacked.
And A/B stalls most definitely can effect the rate of witch we charge when 2 cars are plugged in.

I have never seen 100+KW from a supercharger that was full.... Only when I plug in and the other half of the pair is vacant,

Tropopause | 2 Janvier 2017

OP,

Remember Bighorn's formula. I use it all the time and it works. However, last week the numbers were not adding up ( I was not paired) so I called Tesla for assistance. They pulled up the vitals of my car and told me my battery was cold. Sure enough about 10 minutes later the rate increased and Bighorn's formula was back in play.

Bighorn | 2 Janvier 2017

@mychol
Jaribbs brought in the 6 chargers to the discussion, though his point was entirely temperature related. A/B pairing effects are well known with a 75/25 split between cars sharing a supercharger. The balance changes as the car with priority is current limited based on SOC but it's a stepwise change based on the 12 discrete chargers.

tom-m | 2 Janvier 2017

@Tropopause I will test again at the end of the week. All the stalls were empty so A/B should not have made a difference but I tried 3 different stalls and I ended up sitting in my car almost 45 minutes total and it never exceeded 60kw nor did get close to a full charge. When I left it still showed about 50 minutes left but I had things to do and could not just sit there much longer. Based on the website it showed I should be able to get around 100 mile replenishment on a supercharger in around 15 minutes. It was taking around 3x that time frame.

Bighorn | 2 Janvier 2017

You don't seem to be following the answers that have been given. You arrived with approximately a 50% SOC, so the max kW you would have seen would be 70, which would drop steadily as charge was added. The website claim of 100 miles in 15 minutes is based on an empty battery getting 120kW i.e 120/0.3kw/mile=400MPH. Range charging to 100% takes a long time especially in the cold and is rarely warranted.

tom-m | 2 Janvier 2017

@Bighorn how can I follow answers to see if anything makes a difference if I have not tried it again. I can only go on my past experience and battery is not low at the moment.

Jaribbs | 2 Janvier 2017

Thanks for the additional SC info everyone. As I am by no means an engineer, I was just regurgitating the facts as best as I understood them from my SM. I use the Milford, CT service center and will ask again to see if I get the same answer.

Bighorn | 2 Janvier 2017

The answers above explained why getting "100 miles in 15 minutes" was an unrealistic expectation on your part. The average temperature there, as you know, over the last days of 2016 was 36. Unless your battery is fully warm, which could take 20-30 minutes of driving, the supercharger will also be limited. Sounds like you're just experimenting to see if your car works as promised, but the conditions don't favor getting an accurate or reassuring result. Curiosity killed the cat can work in mysterious ways. Be careful out there.

tes-s | 2 Janvier 2017

Based on the initial post, looks like it is a combination of cold battery and state of charge limiting the charging rate.

Charge rate going up (40kw, 48kw, 60kw) over time looks like the battery was warming up and charging faster. 150 miles left would be about 60% SOC? The would limit charge rate to well below the 120kW capacity of the charger.

tes-s | 2 Janvier 2017

Heat is needed for electricity to flow? I thought electrical resistance of metals dropped as temperature dropped. But it has been a long time since I studied physics and EE, so things may have changed since then.

luckyj | 2 Janvier 2017

I'm a newbie owner, and here's some numbers from today to help reinforce that temperature (and other things, as folks have mentioned) make a big difference.

I started a drive from NJ to VA. Car was cold since it wasn't plugged in overnight (out of town). I was at 66% but I hadn't stopped at the Cranbury supercharger before, so I figured I'd scope it out. Was there for ~15 minutes, only got up to 37kW. Tried all four stalls, no difference. Next stop, Delaware. Started charging at 35%, 118kW! I was at >100kW for about 7 minutes! Left with 75% and was still going at 70kW. Then, didn't need to, but stopped in Laurel since I had not been there either. Started with 48%, 115kW. Was over 100kW for about 11 minutes. Left with 75% charging at 70kW. These are numbers captured by my own tools to pull the data from Tesla, so this isn't a fish story :)

Phaeton | 2 Janvier 2017

It is the electrolyte and other materials in the battery that need to be warm, not the casing.

luckyj | 2 Janvier 2017

Sorry, for those numbers I should have mentioned I have a new P100D.

Bighorn | 2 Janvier 2017

Thanks lucky, that was my obvious question. Interesting to learn the better charging parameters vs the original 85s. Seems to be about a 20kW advantage.

TeslaTap.com | 2 Janvier 2017

@tommilone - perhaps I missed it, but I didn't see which model you have. the 60/70/75 models have a maximum charging power of 105 kWh, and they will taper off a bit quicker than the 85/90/100. This is due the 350 v pack in the lower capacity cars, whereas the larger packs are 400v.

tom-m | 2 Janvier 2017

@TeslaTap.com I have a 90D, I will try to drain it low and see if I can get any speeds over 60kw if the battery is low.

tom-m | 2 Janvier 2017

Is there an equation to demonstrate this? For example under 40% will you see a 100kw charge but over 50% a 60kw, etc?

Bighorn | 2 Janvier 2017

I posted the equation above.

tom-m | 2 Janvier 2017

@Bighorn you posted... *SOC + kW = 125 +/- 7

Can you put that in simple terms?

If you are at 30%, 40%, 50% etc., what charge rate should you expect if at an empty station and you are the sole vehicle?.

luckyj | 2 Janvier 2017

Here's a little more detail of my charging at Laurel:

Minute Power SOC (%)
0 114 48
1 114 50
2 115 52
3 115 54
4 115 56
5 113 58
6 110 60
7 107 62
8 105 63
9 101 65
10 97 67
11 93 68
12 88 70
13 84 72
14 79 73
15 75 74
16 70 75

lilbean | 2 Janvier 2017

A little? Nice documenting!

luckyj | 2 Janvier 2017

Hehe...thanks go to a python script :)

Tropopause | 2 Janvier 2017

The P100D should be able to charge 15kW faster within the limits of the Supercharger, vs. the 85 series.

Pack Mule | 2 Janvier 2017

@TeslaTap. Non-software limited 70Ds are not limited to 105kW max charging. Can't speak directly to the newer 60/75 models but I think it's a fair assumption they aren't either. My 70d (Oct 2015 build ) has seen 116 kW charging numerous times. Amperage capabilities on this model seems to be higher, as the car readings were showing at least 320A (I need to check my notes). This seems to be the divergence from the larger batteries. The differences in charging times to a fixed rated mile target is due to the taper starting at a SOC that represents a lower rated mileage.

OP, your observations are normal. Chill out and listen to the advice you've been given. Battery temp and SOC (%) are dictating the charging rate you are seeing, with some normal variation.

Bighorn | 2 Janvier 2017

On my equation, 30% would be 95kW +/- 7 so 88 to 102. Tend to see the higher end at low SOCs and low at high SOCs.
Your arrival at 50% therefore should have been 68-82kWs, but since it was cold, less. I arrived with 34% after a fifteen minute drive and only got 19kW because the battery wasn't warm yet. You likely need a road trip to see expected charge rates.

kevin | 2 Janvier 2017

Bighorn's formula doesn't apply to the software-limited S60. It charges slower on the low end and faster on the high end.

NKYTA | 2 Janvier 2017

It also does not apply for A batts limited to 90kW max.

Pack Mule | 2 Janvier 2017

@kevin. Did you try scaling Bighorn's formula to account for the software limited capacity, i.e. multiply your SOC by 0.8 then add that number to the charging power?

p.c.mcavoy | 2 Janvier 2017

For those that are visual, here's a graph with data I've over the past couple months supercharging.

https://drive.google.com/open?id=0B7_eZCwFA_8gNlVNQng1SS0wa00

Vehicle is 2016 refresh MS 90D. All the data was collected with Visible Tesla. The kW values were derived by simple formula of kW = volt * amps (VisibleTesla reports volts/amps, not power). Most of these started charging shortly before the line in the graph starts (how quickly I can get to a good wireless spot to start logging). The very top line, taken from the Lafayette, IN SuC actually started at around 25% SOC. The lower lines, where you can see the power flatlined in the 70kW range were due to the battery being colder, although not always to the point where the yellow limited regen line was shown.

None of the cases represent paired stalls.

YMMV ...

kevin | 2 Janvier 2017

@Pack Mule
Scaling the 60 kw battery would work on the high end, but not on the low end. You can see that with this chart:

https://www.youtube.com/watch?v=qXizAtlZGQY&t=457s

Haggy | 3 Janvier 2017

Statements with "up to" don't tell you what's typical. Humans can be up to 9 feet in height. If you find somebody taller than that, it will disprove my statement. What's typical depends on location and circumstances.

tom-m | 5 Janvier 2017

Brought car down to 22% and went back to Supercharger. Checked multiple stalls and max I could get was 54kW. Not sure if it's the station or vehicle but I can never get over 60kW.

GHammer | 5 Janvier 2017

What was the outside temperature and how long did you drive before charging?

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