Slow supercharging in hot weather?

[ThosEM]

900 km with stops at E Brunswick and W Hartford, no problems. Rates stayed above 60 kW through 60%, unlike last weekend at Hamilton and Newark. So it's not my car, and utility limits or just too much heat are suspect. Will be in for drive unit whine service on 12 Sept. and will press for information...

Wouldn't it be nice if rate stayed above 80 kW through 80%!

 

[apacheguy]

Wouldn't it be nice if rate stayed above 80 kW through 80%!

Several 90 kWh owners have reported something close to that. It's unclear why the 85s don't see it since it's just a taper algorithm change.

 

[ishop4more]

When I was charging at Waco,TX midday yesterday at 103F, I noticed that the rate never went above 250mph even at low SOC. I have seen 300mph earlier on other occasions at cooler temps, and so it was a surprise to me.

Now I am wondering if it was throttled.

I was charging in Columbus on Saturday when the weather was in the mid 80s. I got up to 320 mph at times, but when I started, I only had 8% range left. It charged much faster than on Thursday evening when I was at about half range.

 

[DrManhattan]

I've put 5000 miles on my S in the last 6 weeks or so. Lots of Supercharging stops. It's been very hot out on almost all of my trips. Usually 100 degrees plus. I've seen a lot of throttling. I would say 2/3 of the time I get 200 mi/hour or higher which is fine. But every 1/3 time I get 150 or lower (with no other cars charging).

I've experienced charging suddenly stop for no reason. Several superchargers that won't charge. In Nevada none of the chargers were working until I tried the last stall which finally worked. This was in Prim in 115 degrees.
I have not had to wait, and only saw 1 spot where there was a line: Mt Shasta.

The Supercharging experience has been a little frustrating for me so far - but in the end I have always made it with some delay. It would be great to see a more reliable experience and quicker stops.

 

[MITE46]

I've been thinking about this issue...does anyone think it could be the SC gear overheating? Last week at Harris ranch, I started on 1A at 120kw then after 10 minutes it drop down to 60kw. So I unplugged and proceeded to 3A, went at 100kw for 10 minutes then dropped again. I moved to 4A then eventually 5A.

Worked for me, but yes quite ridiculous?

 

[ThosEM]

Completed our trip from Annapolis to Portland ME and back, with good charging rates all around (E. Brunswick, W. Hartford, back to W. Hartford, then Hamilton Twp.) and no need to make extra stops.

At Hamilton I initially tried the same charger #3 that I used a couple of weeks ago with horrible results, but switched to side B. It did exactly what it did two weeks ago: started at 115 kW but by the time I was out of the bathroom (5 min), it was down to 22 kW. I switched to charger #1, and it operated normally, staying above 60 kW beyond 60%. Departed for home with 80%. I called Tesla and reported that the same charger was still acting in the same way and they said they would address it "right away".

For those wondering if their charge rates are as they should be, I strongly recommend switching to energy units rather than distance units for your SOC display. When you use distance, the system reports out your total AVERAGE charging rate since initiating the session, rather then your instantaneous rate as it declines. The effect of that is to smokescreen the actual charging rate, which is read out directly when using energy units (kW). I suspect many of us may be getting poor charging rates, but if we use distance units, it is very difficult to compare from one visit to the next, since your initial rate of charging dominates the average rate over the session, and depends strongly on the beginning SOC.

 

[rypalmer]

For those wondering if their charge rates are as they should be, I strongly recommend switching to energy units rather than distance units for your SOC display. When you use distance, the system reports out your total AVERAGE charging rate since initiating the session, rather then your instantaneous rate as it declines. The effect of that is to smokescreen the actual charging rate, which is read out directly when using energy units (kW). I suspect many of us may be getting poor charging rates, but if we use distance units, it is very difficult to compare from one visit to the next, since your initial rate of charging dominates the average rate over the session, and depends strongly on the beginning SOC.

Agreed that rated range is a poor metric for charging, but if we think Supercharging is limited by heat dissipation somewhere along the stack, I'd advocate comparing amps, not kW. The battery voltage ranges of the different sized batteries varies quite a bit, with the max voltage ranging from ~350v (60kWh) to ~425v (90kWh). The heat generated in the handle would depend on current only, not voltage. The maximum power deliverable is a function of maximum current (~300 amps, it would seem) and the voltage of the battery. You could be drawing 10 volts instead of 425, and still be generating the same waste heat.

 

[ThosEM]

Agreed that rated range is a poor metric for charging, but if we think Supercharging is limited by heat dissipation somewhere along the stack, I'd advocate comparing amps, not kW. The battery voltage ranges of the different sized batteries varies quite a bit, with the max voltage ranging from ~350v (60kWh) to ~425v (90kWh). The heat generated in the handle would depend on current only, not voltage. The maximum power deliverable is a function of maximum current (~300 amps, it would seem) and the voltage of the battery. You could be drawing 10 volts instead of 425, and still be generating the same waste heat.

Maybe that is why Porsche is saying they will use an 800 V pack? I wonder where they will suggest charging it?

You make a good point that we all can read the current instantaneously, regardless of which SOC display units are running, and maybe even multiply out the power. But my main interest is how much energy is going into my battery and not how much is going into the cabling. ;=)

 

[ThosEM]

I've been thinking about this issue...does anyone think it could be the SC gear overheating? Last week at Harris ranch, I started on 1A at 120kw then after 10 minutes it drop down to 60kw. So I unplugged and proceeded to 3A, went at 100kw for 10 minutes then dropped again. I moved to 4A then eventually 5A.

Worked for me, but yes quite ridiculous?

It's not just ridiculous, but downright ludicrous, to be out in an asphalt parking lot with no shade/cover moving a car around in 100+F weather. Or do Californian SCs actually have covers over them? At least when you go to a gas station, you are generally under cover and the pumps that are out of order are marked by the attendants.

This is not a problem that Tesla can safely ignore, IMHO.

 

[rypalmer]

Great news! Got a call from Tesla Service Centre this afternoon... they have acknowledged an issue with Supercharger handles at certain sites - that a sensor in the handle may be overreacting to heat. A tech is coming "this week" to take a look apparently. It will be pretty obvious if the handles get replaced at Toronto, so I'll be sure to report back.

 

[gaswalla]

Doesn't make sense to me - I've been supercharging since day 1 - almost 4 years now. Never had this issue until this summer. What changed?

 

[miimura]

Doesn't make sense to me - I've been supercharging since day 1 - almost 4 years now. Never had this issue until this summer. What changed?

It could be wear and tear. Over time, the contacts in the handles get dirty or wear out, increasing the contact resistance, which creates heat. If there is thermal monitoring in the handle, then it could be triggering the reduced power after 10 minutes of high-amp charging. Moving to another stall would start charging on a cold handle, but if it has the same wear, then it would also ramp down. So, it seems that new cables are the answer. It also makes sense that we see these issues in California and the Eastern Seaboard since those are the stations that get the highest use and therefore the most wear and tear.

 

[CSFTN]

I asked a related question in another forum - but never answered. I am going to ask again, this time in relation to post #52 above.

Do the contacts of a charger need occasional cleaning? How would one know, how would one do it? Anhydrous alcohol and a q-tip?

 

[MITE46]

Back at Harris ranch. This time 81F outside. Started out 120kw then quickly dropped to 60kw. Came back and opened the door and it shot up to 90kw. Very strange.

Maybe pack is not getting enough cooling? Suspension is set to low.

 

[MITE46]

A couple of experiments yesterday...50F outside temperature...ramped up to 110kw relatively quickly then sudden drop to 50kw. I was able to repeat this 3 times at Tejon ranch yesterday. It seems related to the nozzle temperature, once it exceeds 120F it takes a nose dive...

In each case the nozzle started out at 50F and then ended up at 120F within 10 min or so? Perhaps dirty contacts?

But this was never a problem before 2016...must be a software update or something?

 

[MITE46]

Hmm I take it back...charged at Gilroy at 110kw for a solid 15 minutes with handle temp at 120F...recovered 90 miles very quickly.

 

[twonius]

Perhaps it's just the variables of the rate of charge curve as well as other cars but i feel like supercharging speeds will need to become more predictable as demand increases.

Since we actually pay for supercharging in the price of the vehicle, i sometimes wonder if I should be more annoyed with unexpectedly slow charges as I'm not getting what I paid for.

 

[apacheguy]

Perhaps it's just the variables of the rate of charge curve as well as other cars but i feel like supercharging speeds will need to become more predictable as demand increases.

The rate of power delivery at superchargers used to be extremely predictable and consistent at least in my experience.

 

[MITE46]

Superchargers in California seem to be much faster now. Anyone feel the same? In getting 110kw in both harris and tejon ranch in 93F degree weather for at least the first 20 minutes.

 

[hickin]

I did 5 hours of driving on 6/12 and had no problem getting 110 kilowatt charging rate at the Kingston NY station when it was literally 100 degrees outside. Was pleasantly surprised to get that charging rate.