Tesla Supercharger Cable Too Hot To Handle? – Video


Too Hot To Handle

Too Hot To Handle

Perhaps this is why Tesla is adding liquid cooling to its Supercharger cables?

YouTuber Kman Auto states:

Tesla Motors: Good Reason WHY Liquid Cooled Supercharger Cables are needed! 180*F

This has happened a few times over the past couple weeks at a number of different Superchargers I have visited. Given that, while on my road trip, we visited over 40 stations, as well as a few more then once, I got to really get a good look at temp build up. While not all of them got this hot (Happened 3 separate superchargers), when it does happen, it gets REALLY hot.

I measured 180*F at the handle on this one.

Weather it has to do with my car, or the cable, not too sure, but, if it’s the car, why would it happen only randomly? And why would the whole cable to the station heat up so much?

KmanAuto is later asked in the video comments what Tesla had to say about the issue:

“Reported it. Was sent to supercharger team. SC Team are some good people! What happened, is the car will reduce amperage until the thermal issue is resolved. In my case, every time, it dropped to about 50kW charge rate, and then went back up once the thermal event was over, but the cable did cool down and stayed cool even after the charge rate increased. I have taken to cleaning the charge handle contacts now with cotton swabs on the superchargers now. They are NASTY!!!!”

Categories: Charging, Tesla


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51 Comments on "Tesla Supercharger Cable Too Hot To Handle? – Video"

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So much for the “elegant design” of the Tesla port and cable. The small cable can’t dissipate heat like the properly designed Chademo and CCS standards.

I await the Tesla fans to try and explain this away. After all, they’ve criticized other standards and their charging plugs and cables for years.

The properly designed CCS and CHAdeMO?!

Excuse me while I crack up for a while…

Perhaps you should laud the supercharger for its clever ability to burn users or make coffee?

Perhaps you should laud Chademo and CCS cables for their ability to maintain low temperatures by charging really slowly? The “fast” rate for Chademo and CCS (for all but 1 or 2 stations in the world) is 50kw, which is the “slow” rate for the Tesla Super Chargers. I would prefer to charge faster and have a hot handle that charge slowly and wait around for another hour. Also, the user in this video didn’t actually “burn” their hand, it was just very hot.

No kidding! I’ll carry around an ovenmitt in my frunk if it means getting 200 miles in 40 minutes versus 3 hours while on a roadtrip!!

Conversely in the wintertime you won’t need mittens, just hold onto the plug while supercharging πŸ˜‰

They are designed for 200kW – CCS and 170 kW chademo. Not yet build because no car can take it.

Ah, they are not designed for anything over 200 amps.

They could be designed for more, but they aren’t. New revisions to the standards are necessary.

taser54 said:

“I await the Tesla fans to try and explain this away.”

I would have thought it was obvious that pumping a lot more electric current through a cable of a given size produces a lot more resistive heating.

It is curious, though, that only occasionally does the cable heat up sufficiently to be literally too hot to handle; this isn’t the first time I’ve seen this reported. Apparently, from what the Tesla rep said, this only happens when the contacts are dirty.

Do you take pride in being a colossal idiot? The article clearly states that Tesla has started putting liquid cooling on their charger cables, which demonstrates they’re resolving the issue.

Think before typing next time, please.

As stated in the article, it does not happen all the time, and when it does happen, the charge rate is adjusted until it cools down again. This is the same thing that a cell phone does if it starts to overheat.

Maybe someone forgot about the rate of thermal transfer. You can hold a piece of material in your hand that is over 1000 degrees and not get burned. Here is the video from NASA.
So it really does not matter what temperature the outlet is, it matters what the thermal transfer is of the material, which happens to be relatively low so the operator only feels a warm plug. Nice try!

Electricity is converted to heat as a result of resistance, similar to a friction trying to prevent flow. I suspect this results from more than normal resistance occurring within the supercharger handle itself, perhaps as the result of a loose connection or defective cabling within the handle. The car is still going to try to pull the same number of amps, regardless of increased resistance in the cable/connector.

This later video shows how he now cleans the contacts to reduce resistance / heat.

The connection between the car and the cable is a bottleneck for current flow, due to the small cross-section of the contacts. The last time we discussed this subject here on InsideEVs, someone claimed that the handle was always the hottest part of the charging “chain”. Sounds reasonable, due to that bottleneck, and I have no reason to doubt it’s true.

In general, the contact surface is always the highest risk.

Most wires can be easily dealt with by using the standard design guide with amount of current required vs. size of the wire for a given operating temperature/duration. That is pretty much something you can look up in a manual.

But the contact surface is definitely an easily overlooked engineering problem. It sounds simple but it is often overlooked in the real world.

The contact surface is usually the “weakest” link due to the corrosion factor and mechanical contact wearing/tearing issue. The safer approach is always use the most conservative approach by beefing up the contact and derate the design sufficiently AND using better corrosion resistance material/plating combined with routine services.

There have been discussions about preventive maintenance on the charging port on all electric cars. Different lines of thought on that but a compressed gas duster can is a good start to keep it free of debris and dry.

Looks like it’s at the charge cable right at the interface.

I doubt the cooling fluid reaches all the way to that point. Can anyone confirm?

Confirmed. The handle is NOT liquid cooled and gets VERY hot.

The cables themselves remain just warm to the touch.

I would imagine even if the liquid doesn’t reach the handle, a lot of heat would be conducted away by the copper cabling inside.

It can and it will. But you will still have a long temperature gradient. If you look at typical EVSE plugs, you will notice that the plug are generally much hotter than the wires. Those copper wires do transmit heat well. But they are thin. So, the amount of generated at the plug still can overheat the plug without overheating the wire. In addition, with the protective coating, the wire actually has a much larger surface area to dissipate heat relative to the surface area of the plug where the heat is concentrated. The liquid cooled cable will help a lot, but it won’t eliminate the plug issue (unless you have very thick copper conductor from the plug to the liquid cooled part of the cable. Pure copper (one of the best heat conductor) can do about 380W/mK to 420W/mK in heat thermal conductivity. Brass (likely used on common electrical connectors) are about 1/4 of that of pure copper. The best thermal conductor would be Diamond but it is considered as an insulator. So, maybe the ideal thing would be some kind of graphite composite that would have both great thermal and electrical conductivity to bridge the path between the… Read more »

Diamond which is lab grown can be doped with boron to become a semiconductor.

Not sure if that helps or not. πŸ™‚

I think with 120kW, we would need “conductors”, not “semi”conductors… =)

I believe this is just a regular Supercharger cable and not one with liquid cooling.


What model FLIR are you using, KMAN?

Would be interesting to try and correspond the ‘hot’ locations with the number of location charging instances to see if its contact wear. Though as the author states that after cooling and then ramping back up to full charge the handles do not return to the hot state, it would seem like the pins and contacts may be worn, and have issue with correct interfacing, then once expanded due to heat are then making good continuous contact.

This was one of Kman’s most informative videos. I knew Tesla had a problem with their 14-50P adapter, I wasn’t aware until this video there was any problem with the car jack. But there is obviously a bad/worn connector problem since at the relatively low 50 kw rate the OUTSIDE of what he is looking at is already over 82 deg Centigrade. Industry standard terminations are designed to be ok up to 75 degrees. I would wager the EXACT temperature at the contact points is near 100 degrees if he’s getting 82 on the outside where the heat can dissipate, as indicated by the ’round orange glow’ around the jack (the car itself is cooling the connection). I don’t see this as being a need for a water cooled cable, since some of the vehicles run 120 kw without it (albeit not for long), and when he put the flir on the cables they were obviously very cool. The problem is at the car recepticle, either worn on the car, or the 2 conductors on the stall jack. When this cools, I would gather there would be a different ‘feel’ to this connection as opposed to a new one. Tesla… Read more »

I charged at Eau Claire, Mauston, Madison, and Country Club Hills Superchargers in the past week and none of them even felt warm after 20-40 minutes of charging.

“But there is obviously a bad/worn connector problem since at the relatively low 50 kw rate the OUTSIDE of what he is looking at is already over 82 deg Centigrade.”
I think you misread it. He says that he was charging at higher power and then it ramped down to around 50kW, at which point it cooled off and it ramped back to higher power.

“If this is happening to Kman’s 60 then its surely happening to others.”
A 60kWh pack is actually worse for this. It needs to push more current for the same amount of power given the lower battery voltage (charging voltage ~352V vs ~400V for 85kWh).

It could a connector corrosion issue or contact pressure problem…

The cable at the time was relatively cold.

@ Bill,

You are right. 80 deg C would be a safety violation. 75deg C requires a warning label already.

I wonder if this qualifies as design defect or maintainence issue.

I guess that is why Tesla want liquid cooled cables.

I think better cable connecter and plating would help too…

Q-Tips aren’t gonna do dip.

I agree.. It will only clean the dirt or grease off it if any…

Most the heat problem is due to poor contact due to design (lack of mechanical pressure or surface contact) or contact surface corrosion. None of them will be fixed by “Alcohol infused Q-Tips”.

I’ve never had an “excessive temperature” event with the cables at a Supercharger…. Perhaps there’s a defect in the cable causing resistance and the resulting heat?

Grammar Nazi says:

“Weather it has to do with my car…”

Perhaps it was hot outside πŸ™‚ , but that should be “whether”…

Sounds like yearly cleaning of the plug should be part of standard yearly service procedure.

I wonder how much money I could make re-labeling bottles of isopropyl alcohol an selling them as “Super Charger Cleaning Fluid”?

I don’t know what type of coating/plating those connectors have, but alcohol won’t get rid of corrosion. It will do a great job at cleaning though…

If the contact are under high temperture and there are sulfur nearby, it will easily corrode gold and silver plated connectors..

I didn’t say it would actually work, just that I could make a lot of profit selling it….. *smile*

I was actually just joking about typical dealer markups in the automotive world, and joking about how the price of a simple cleaning solution ends up getting jacked up. I should have added the /sarc tag….

I actually had this stuff in mind when I posted:

Genuine OEM Mercedes Benz Winter Fit WindShield Washer Fluid Concentrate 1 Liter


That’s $22 dollar windshield washer fluid, for Mercedes owners… Crazy. For basically a fancy container of alcohol that makes 1 gallon of windshield washer fluid.

Oh, and you have to add this stuff too into each gallon if you want to actually clean your windows, at 7 bucks a bottle:

MERCEDES GENUINE Summer Fit Windscreen Washer Concentrate 40ml 1.34 fl


Of course you should use distilled water to mix this with. So $30 bucks later you have $5 bucks worth of windshield fluid….


Be sure to include a little tube of electrical conductor paste with that.

Maybe a little Super Lube dielectric grease on the Q-Tip?

That would be a $20 dollar “upgrade” to the standard kit.



But how much premium is there if there is a Telsa logo on the bottle?

What about Elon signature bottle? πŸ™‚

I wonder what the ambient temperature was when the video was taken.

Nevermind, the second time I watched, I heard him say “about 70”.

Tesla Super charging Mitts $500 a pair
Made in USA

Do you sell a Gucci version? Ready buyer at $1,000….


Gucci and Versace are on the way for a princely sum of $1590.00 a set LOL

Does anyone know what thermal imaging camera was used in the video? (Make and model#)


Tesla should have hired someone who knew something about electricity. Every one of their major products that was not a rebranded Clipper Creek has been in trouble.

I chawk up my cool-running TSL-01 connector on the Roadster to the caution of the 3 engineers who died early on. I just wish those guys didn’t live in Southern California since then my REGEN would have worked in the wintertime and the brakes not wear out so fast, and the connector probably would have constantly frozen if these guys were from somewhere like Fargo.

Would Not