HPWC Charge handle temperature @ 80 amps

[MyJoule]

I just checked my cable/handle area while charging at 64Amps after about 30 min of charging in a 91F degree garage, the temperature according to my non-contact thermometer was 170F. The handle itself at the button was 134F. I called the service center in Scottsdale and asked if this was ok, and was told it's not a problem ---it's pretty hot in AZ and to not worry about it.

I guess I'll take their word for it.

 

[AmpedRealtor]

I just checked my cable/handle area while charging at 64Amps after about 30 min of charging in a 91F degree garage, the temperature according to my non-contact thermometer was 170F. The handle itself at the button was 134F. I called the service center in Scottsdale and asked if this was ok, and was told it's not a problem ---it's pretty hot in AZ and to not worry about it.

I guess I'll take their word for it.

Ditto. I swear you could fry an egg on the nozzle here in Arizona when charging at 80A, but was told the same thing - it's normal, heat is additive, don't worry about it.

 

[MyJoule]

AR- thanks, We should be ok as long as it stays dry- the cable is rated for 105C(Dry) and 60C(wet) at least that is how it's marked. That's 221F and 140F .. As long as it's not raining in my garage I guess I'll ignore it. I'm going to look at the contacts for dirt tonight though.

 

[MyJoule]

My wife's S85 after charging about 1 hour is also showing quite high temps- The cable is 180F near the connector. I think I'll call Tesla again about it. this really seems too high to me Meanwhile I'm going to go crank down the current from 64Amps to 45Amps ( that way both chargers still share the load )

 

[Dave EV]

I charge an average of 1 hour a day at 240 volts and 80 amps. Each month that translates to 4.1 kWh of wasted electricity, and at my current electrical rate it costs me $0.42 to heat the cable. Before I finished this calculation I was considering shortening the power cable by 15 ft to reduce energy waste and to tidy up that garage since I do not need 25 ft to reach the charge port. This would save me 83 watts and a whopping $0.26 a month.

Instead of using a shorter cable, you could just charge at 60A instead of 80A and cut the energy loss in half. Just bump it up to 80A when you need full speed. Go all the way down to 40A and you'll cut the energy loss by 75% (~30W of loss instead of ~130W).

The main question is the charging overhead in the car fixed or will it also go down a proportional amount at least? Often there are fixed overhead charging costs (like cooling pumps) and those cooling pumps can pull 100W on their own. So while your cable may stay cooler, the overall energy used remains the same or higher.

Of course, if the thermal management system needs to kick into overdrive to keep the pack cool, then you could save even more energy.

 

[MyJoule]

I just got a call from Chris at the Scottsdale service center. he said that is too hot and that they would be sending someone to replace it- meanwhile I will run at 45 amps as I stated above until they change it out. I'm impressed with the service from Tesla.

 

[MartinAustin]

I keep my car in the garage of my house in Austin, Texas. The ambient temperature in there on a hot day can be 92F. (this is while it's in the mid-70's inside the air-conditioned parts of the house) My HPWC cable+handle already got replaced under warranty, last year. I had the exact same problems described above. The HPWC handle always gets very hot, and I typically keep a towel around that I can use to grip it and depress the button to get it out of the car. The end of the rubber cable that connects to the car plug was SO hot that I could not touch it without burning myself - that's when I measured it with one of those laser thermometer things and saw that it was like 135F.

The Tesla engineer agreed this was too hot, but he said something interesting - the cable itself has a design flaw (effectively) wherein it "bends" at the joint where the cable is going into the plug, due to the heavy bulk of the rest of the cable pulling downwards. That bend creates more resistance, which causes more heat (and undoubtedly causes the efficiency of the charger to drop below 92%, though that's hard to measure without metering installed)

Also, I was at a Texas vineyard recently that has a couple of "destination charging" HPWCs. (let me give them a plug, no pun untended, Torre di Pietra | Romance of Tuscany, Wines of Texas!) The Texas summer sun was shining down and the ambient temperature was approx 103F. The entire cable was extremely hot while it was charging my car at 80A. The manager at the vineyard said they were still in the process of building out this area of the parking lot, and there would eventually be an awning over all this, thus getting it out of the hot sun.

The moral of this story is, "roll on liquid-cooled HPWCs" - I am sure Tesla is working on a new HPWC that sidesteps this whole issue. They may end up with a three tiered home charging product range - the "classic" or "some like it hot" HPWC, the new liquid-cooled "cool customer" HPWC, and the Tesla Snake.

 

[AmpedRealtor]

I just got a call from Chris at the Scottsdale service center. he said that is too hot and that they would be sending someone to replace it- meanwhile I will run at 45 amps as I stated above until they change it out. I'm impressed with the service from Tesla.

Can you please keep us in the loop on your replacement, and if that works better for you?

 

[MyJoule]

Will do--- it's scheduled to be replaced later this week.

 

[pgiralt]

Mine was over 175 degrees on the handle before it was replaced a couple of months ago. Now it doesn't even hit 120 after 30 minutes of charging at 80 Amps. I had posted a thread here with some FLIR ONE shots:

HPWC + New FLIR ONE for iOS

 

[Zroiron]

We had the same issue with our cable getting so hot that you didn't dare touch it. The service center was notified and they scheduled me for a brand new HPWC including the cable. This was just over a year ago, however, I've noticed that the cable is getting very hot again when charging at 80 amps. The circuit is 100 amps so I don't understand why 80 amps makes the cable so hot! Don't want to burn the garage down

 

[Khatsalano]

How do we measure handle temperature without fancy equipment? Right now, my handle does get warm, but I'm not sure it's getting into the out-of-spec range. After reading my post here, Tesla contacted me and offered to help me diagnose the problem and maybe service/replace the unit ... that was very good customer service. But I'm just not convinced mine is out-of-spec.

- K

PS: I've also learned not to post my VIN number in my signature because of this interaction with Tesla ... just feels weird to be watched.

 

[blanche]

How do we measure handle temperature without fancy equipment? Right now, my handle does get warm, but I'm not sure it's getting into the out-of-spec range. After reading my post here, Tesla contacted me and offered to help me diagnose the problem and maybe service/replace the unit ... that was very good customer service. But I'm just not convinced mine is out-of-spec.

IR thermometers are less than $20 on Amazon. However, I have one of these handy IR + probe thermometers that I use in the kitchen every day when making dinner. The IR end is used to make sure that griddle pans are in the right heat range, etc., when cooking. Apparently, also useful in the garage.

ThermoWorks - Combo Thermometer - Infrared + Thermocouple Probe Thermometer

If you already own a probe thermometer for grilling, perhaps it is sensitive enough if you touch it on the HPWC handle?

 

[Zroiron]

How do we measure handle temperature without fancy equipment? Right now, my handle does get warm, but I'm not sure it's getting into the out-of-spec range. After reading my post here, Tesla contacted me and offered to help me diagnose the problem and maybe service/replace the unit ... that was very good customer service. But I'm just not convinced mine is out-of-spec.

- K

PS: I've also learned not to post my VIN number in my signature because of this interaction with Tesla ... just feels weird to be watched.

I didn't post my vin, but I just got a call from Tesla about my comment above! They've scheduled me for a cable replacement in a couple of days! Awesome, freakin' awesome!! Watch me all you want!! Nothing to hide here!

 

[MyJoule]

All- My HPWC cable was just replaced and I did a charge- the new cable temp rise was less than 10 degrees from ambient while charging at 64 amps.. Thank you Tesla for your fast response to this issue. Way to go!

 

[redi]

All- My HPWC cable was just replaced and I did a charge- the new cable temp rise was less than 10 degrees from ambient while charging at 64 amps.. Thank you Tesla for your fast response to this issue. Way to go!

Basically the same here. I am curious to see if these cables deteriorate over time with use. I do not recall having the issue when the HPWC was new.

Whether repeated cycling and movement of the cable has some effect we'll have to wait another 2 years to see.

 

[m6bigdog]

Basically the same here. I am curious to see if these cables deteriorate over time with use. I do not recall having the issue when the HPWC was new.

Whether repeated cycling and movement of the cable has some effect we'll have to wait another 2 years to see.

You don't need to wait and see...
I guarantee the Tesla charge connector degrades with time if the HPWC is used daily at 80 amps (20kW) or Supercharged daily/often (90-120kW).
If you look at the industry standard NEMA 100amp connector (80amp continuous load - as all electrical connectors can only be used to 80% for the max current rating) they are huge compared to what Tesla has selected for a charge connector.

I would suggest that if you want your HPWC and charge connector to last (be reliable) you will charge at a rate sufficient to complete the daily charge during the night without exceeding 50 amps (12.5kW). After all, even a 24 amp (6kW) charge rate will provide a 100 mile recharge in 6 hours and that will be much less stressful on the HPWC and charge connector reserving the real stress for the occasional short duration Superchargering events.
The 80 amp charge rate generates 2.5 time more internal power loss and heat in the HPWC and cabling than charging at 50 amps while 24 amps generates 11 times less power and heat while providing 30% of the charging rate of 80 amps.

So while the fast charge rate of 80 amp @ 58 mi./hr seems desirable it is also very stressful (potential to generate a lot of heat) on the EVSE and given the daily charge requirement for most owners is unnecessary.

 

[AmpedRealtor]

Scottsdale Service is sending an electrician to my house on Monday to swap HPWC cords. I charged at 80A for at least 2-3 hours on Thursday in my garage. When I went to unplug the HPWC, my burn reflex kicked in and I had to drop it. I was holding the rubber cable with my other hand, so thankfully it didn't hit the ground, but I could not keep my hand on the handle long enough to carry it two feet to the cable organizer. My hand stung a little bit afterward, but there was no burn.

I don't remember it being this hot before. My HPWC cord does not apply any downward pressure on the handle given how I have it looped and that the cord does not hang significantly below the handle. This hot HPWC cord is a replacement that I received about a year ago when my original failed. This new one has always felt warmer, and I noticed some increased resistance (lower voltage) than with the original cord/handle.

Hopefully Monday's replacement will behave a little bit better. I do wish that Tesla used thicker cabling to reduce resistive losses. I don't think the HPWC should get this hot.

 

[FlasherZ]

From what I can tell, the HPWC connector's pin-sleeves are wearing mechanically over time. A thorough cleaning does very little to reduce the temperature - so it's not dirty contacts, and it just seems as if the mechanical connection is working its way to be less tight than it is when new. I've had my cable replaced 3 times now, each time due to high heat exceeding 180 degrees F when charging at 80A. Each time the heat dropped dramatically, so it doesn't appear that the car connector's pins are wearing.

 

[redi]

You don't need to wait and see...
I guarantee the Tesla charge connector degrades with time if the HPWC is used daily at 80 amps (20kW) or Supercharged daily/often (90-120kW).
If you look at the industry standard NEMA 100amp connector (80amp continuous load - as all electrical connectors can only be used to 80% for the max current rating) they are huge compared to what Tesla has selected for a charge connector.

I would suggest that if you want your HPWC and charge connector to last (be reliable) you will charge at a rate sufficient to complete the daily charge during the night without exceeding 50 amps (12.5kW). After all, even a 24 amp (6kW) charge rate will provide a 100 mile recharge in 6 hours and that will be much less stressful on the HPWC and charge connector reserving the real stress for the occasional short duration Superchargering events.
The 80 amp charge rate generates 2.5 time more internal power loss and heat in the HPWC and cabling than charging at 50 amps while 24 amps generates 11 times less power and heat while providing 30% of the charging rate of 80 amps.

So while the fast charge rate of 80 amp @ 58 mi./hr seems desirable it is also very stressful (potential to generate a lot of heat) on the EVSE and given the daily charge requirement for most owners is unnecessary.

Thanks for this info. I suspected as much. I charged at 80A only for the first few months (probably the last quarter of 2013) then backed it off to about 60A, then further to 51A for the last year or more, partially because of concern about unnecessary heat/stress, partly because my daily missions did not call for charging that rapidly.

I've since dropped it to 30A given my daily use requirement is still fast enough. If I need it, or I get a travling plugshare visitor, faster is only or two away. Even with this new use pattern, I am still curious how the cable might deteriorate over time.

Do the UMC users experience anything like this with the highest current options over time?

- - - Updated - - -

From what I can tell, the HPWC connector's pin-sleeves are wearing mechanically over time. A thorough cleaning does very little to reduce the temperature - so it's not dirty contacts, and it just seems as if the mechanical connection is working its way to be less tight than it is when new. I've had my cable replaced 3 times now, each time due to high heat exceeding 180 degrees F when charging at 80A. Each time the heat dropped dramatically, so it doesn't appear that the car connector's pins are wearing.

I am wondering if the UMC or Euro plugs will exhibit the same thing after years of use? Thinner wire can get away with carrying the same current because of the higher Euro voltage?