-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Charging Cable is Warm While Charging
- Thread starter tguy888
- Start date
Yep. Normal. I 'turn down' charging current to 20A unless I need faster, figuring that less current means less resistance loss and thus less heat in the cable.
Well, a couple of things. This could simply be I*I*R losses, with the wire heating up along its length (not dangerous). Or it could mean that a connection at one end or the other is getting seriously hot because of a bad connection, which could very definitely be dangerous. As in things catching afire.
The Gen 3 cables use less copper then the Gen 2 TWCs because they’re rated for less current. So a little heating over a few hours wouldn’t be any worse than what one sees on a vacuum cleaner cord, something that also warms up with use.
Next time you charge and the cable gets warm as you noted, check the cable at the middle and ends. If it’s close to the same temp throughout, stop worrying. If it’s Really Hot, like watch-it hot at one end or the other, you may have a poor connection at one end or the other. If there’s a hot spot at the TWC end, there may be a loose screw in there. Pop the breaker, get the cover off, eyeball for melted/singed plastic, and, if things aren’t destroyed in there, tighten the heck out of the screws. If things are destroyed, stop using the TWC and get a replacement, possibly under warranty.
If the Tesla connector is seriously hot to the touch, something I note you didn’t complain about, see the last sentence of the paragraph above.
I suspect that your issue is normal cable heating, though.
Had a friend who had been checking his car’s oil via dipstick out in the company parking lot one day, brushed his hand against a wire in the process, it was Hot! He asked me to come look it over since I he knew I worked on cars sometimes.
Fun. The big, thick copper connector that clamped to the positive terminal of the car battery was cracked and could not therefore be tightened. The insulation was somewhat melted on the wire side and the battery didn’t look all that healthy, either. Solution was to get a new connector from an auto parts store, cut off the old one, and bless the heavens that there was enough slack to get the wire repaired. And I gave him the standard lecture about using water-excluding grease and those anti-corrosion washers when putting it back together.
The Gen 3 cables use less copper then the Gen 2 TWCs because they’re rated for less current. So a little heating over a few hours wouldn’t be any worse than what one sees on a vacuum cleaner cord, something that also warms up with use.
Next time you charge and the cable gets warm as you noted, check the cable at the middle and ends. If it’s close to the same temp throughout, stop worrying. If it’s Really Hot, like watch-it hot at one end or the other, you may have a poor connection at one end or the other. If there’s a hot spot at the TWC end, there may be a loose screw in there. Pop the breaker, get the cover off, eyeball for melted/singed plastic, and, if things aren’t destroyed in there, tighten the heck out of the screws. If things are destroyed, stop using the TWC and get a replacement, possibly under warranty.
If the Tesla connector is seriously hot to the touch, something I note you didn’t complain about, see the last sentence of the paragraph above.
I suspect that your issue is normal cable heating, though.
Had a friend who had been checking his car’s oil via dipstick out in the company parking lot one day, brushed his hand against a wire in the process, it was Hot! He asked me to come look it over since I he knew I worked on cars sometimes.
Fun. The big, thick copper connector that clamped to the positive terminal of the car battery was cracked and could not therefore be tightened. The insulation was somewhat melted on the wire side and the battery didn’t look all that healthy, either. Solution was to get a new connector from an auto parts store, cut off the old one, and bless the heavens that there was enough slack to get the wire repaired. And I gave him the standard lecture about using water-excluding grease and those anti-corrosion washers when putting it back together.
Last edited:
davewill
Active Member
Warm is perfectly normal. However, if it's getting seriously hot, you should look into it. I've had two instances in my 11 years of driving electric of handles and cables going bad. The first time, my car would fail to charge unless I flexed the cable. I suspect that the pilot signal wire was broken near the handle. The second never actually failed to charge, I just noticed that the handle was WAY too hot, then noticed my charge port was slightly melted. Both times I replaced the cable and handle assembly with a better quality one.
That second time, because it was my wife's car, I hadn't noticed before there was damage. It pays to inspect the equipment for heat or visible damage on a regular basis. For me, that consists of checking for heat after the car has been charging for a while, and opening my EVSEs and the coverplates on my outlets once a year or so and looking for evidence of overheating.
That second time, because it was my wife's car, I hadn't noticed before there was damage. It pays to inspect the equipment for heat or visible damage on a regular basis. For me, that consists of checking for heat after the car has been charging for a while, and opening my EVSEs and the coverplates on my outlets once a year or so and looking for evidence of overheating.
sleepydoc
Well-Known Member
not a bad idea. As long as it doesn't get too hot the heat doesn't damage anything but like @Tronguy said, resistive power loss is proportional to the square of the current so cutting the current in half cuts the heat and power loss in the cord by 75%.
@tguy888, the posts here are correct. It's normal go get warm but if it's downright hot or if it's the handle itself that could be a sign of problems.
The supercharger cables are actually liquid cooled to deal with the heat generated from the high currents.
Tesla Introduces New Liquid-Cooled Supercharger System
Tesla introduces a new liquid-cooled Supercharger with thinner and more flexible cables capable of charging at higher power.
www.teslarati.com
sleepydoc
Well-Known Member
Acceptable temperature depends primarily on the type of insulation used. Copper doesn’t melt until about 1000°C, but the insulation will melt and burn long before that. 125° F should be ok, regardless but it’s impossible to say without knowing more.
I asked Clipper Creek about the 125f temp of my charging cable. His response:
...So the rubber jacketing of the cable is rated for 105°C and the internal wires are 10AWG 90°C, which means they can withstand 221°F and 194°F respectively. With that kind of ambient heat in your area and charging during the day the cable is definitely going to get hot. However, we do have these stations installed outdoors throughout California, Arizona, Nevada, Texas, etc, where they have the same heat, plus direct sunlight and there has never been an issue. Just be mindful of the cable when going to grab it and maybe keep it more uncoiled during hotter times so the heat can dissipate faster.
THESE ARE CLIPPER CREEK NUMBERS, NOT Tesla EVSE numbers. Tesla should be able to answer the same question.
...So the rubber jacketing of the cable is rated for 105°C and the internal wires are 10AWG 90°C, which means they can withstand 221°F and 194°F respectively. With that kind of ambient heat in your area and charging during the day the cable is definitely going to get hot. However, we do have these stations installed outdoors throughout California, Arizona, Nevada, Texas, etc, where they have the same heat, plus direct sunlight and there has never been an issue. Just be mindful of the cable when going to grab it and maybe keep it more uncoiled during hotter times so the heat can dissipate faster.
THESE ARE CLIPPER CREEK NUMBERS, NOT Tesla EVSE numbers. Tesla should be able to answer the same question.
davewill
Active Member
Not a very useful response since temperatures well below those values would likely mean that some connection is generating excessive heat and may be close to catastrophic failure. Do they seriously suggest that if the cable and handle gets hot enough to burn me, that I should just "be mindful"? I also seriously doubt "there has never been an issue". I'm sure that hundreds, if not thousands of their units have failed over all the years that Clipper Creek has been selling EVSEs. By their nature, they get plugged and unplugged often and cables and plugs wear out.
Just repeating my self a bit. So, got a Gen 2 TWC. The cable gets warmish after charging for a while, but not hot. I mean, it's an un-airconditioned garage, it gets hot in there in the summer, but the cable's never been so hot that I've started playing hot-potato games with it, not even close. And the thing's been in use since 9/2018.
I'd say that the canister vacuum cleaner that's, what, 25+ years old now, but still works, has a hotter power cable. Still not enough to play hot potato, but cooler than the Tesla's cable.
If the OP had been saying that the cable was hot, that's one thing. But, so far, he hasn't said that: He's said it's warm. No reason to panic, no reason to drop the current down by a factor of two. Just use the blame thing.
I'd say that the canister vacuum cleaner that's, what, 25+ years old now, but still works, has a hotter power cable. Still not enough to play hot potato, but cooler than the Tesla's cable.
If the OP had been saying that the cable was hot, that's one thing. But, so far, he hasn't said that: He's said it's warm. No reason to panic, no reason to drop the current down by a factor of two. Just use the blame thing.
Last edited:
sleepydoc
Well-Known Member
It was a very useful response. @Pianewman asked about the cable temp and they answered with clear information on what temps the cable can handle.
Similar threads
