Join The Community

Charging cable warm to the touch... normal?

When I'm recharging using my NEMA 15-50 circuit, the cable feels warm to the touch. Not burn your hand hot, but pleasantly warm to the touch.

Is this normal? Anyone else notice this?

Sounds normal. 40 amps is a lot of current, it's bound to get warm.


Sounds fine, but make sure you are not using extension cords, or at least not roll/reel in/tangle (I am not confident about my English right now) that extension cord... That could be dangerous if heat can't escape.

Normal for mine. Not hot, but warm to the touch near the end especially.

No way! They must've forgotten to use the superconducting wire.


BrianH- cant get the wire to zero kelvin yet!

Thanks for the reassurance! No extension cords. THe outlet is just two feet from the charging port!


High-temperature superconductors are (always) just around the corner ...

I call TM to inquire about the same thing. They assured me the warmth felt while charging is normal and that the connector is not at risk of breaking down.I was initially concerned that there could be thermal runway occurring in the control box.

As long as you can hold it indefinitely, you are fine. Most recent wiring is rated for 90 degC, which even through insulation you wouldn't be able to hold for long. Older wiring has insulation is only rated for 60 degC, but even that will be too hot to hold.

Yep, it's totally normal. That's a lot of current. It's too bad though, doesn't the heat mean lost efficiency?

@phb - yes, but the only thing you can do about it is send the same amount of power at higher voltage and lower current to minimize losses due to resistance (which is why power distribution lines run at very high voltage).

I don't know how much of it is in wiring vs charger vs batteries, but the typical charging efficiency is a bit under 90%.