openinverter forum

As written elsewhere I have swapped my cables from the charge port to the battery for thicker ones.
Here I want to present the previous 10mm² cables after many, many quick charge sessions. A sample from the lower end of wire gauges. not a recommendation!

Typical charging sessions were 12-15 kWh and about 10-15 minutes full load charging at 115A. Sometimes 135A, once even 180A on a 100 kW CHAdeMO charger But for a minute only, then it dropped back down to the usual 125A.

So, the red cable which is properly crimped shows no sign of being thermally overloaded while the one end of the blue cable definitely overheated because it wasn't crimped properly.

Neato.

10mm^2?

That's barely even 7 gauge, 3.6mm diameter.

Even for chassis wiring that's only rated for 90 amps.

That's only 5x the cross section of standard home wiring in north america.

Interesting to see that it still sort of survived.

Umm... glad you're replacing them.

Amp rating also goes by length. Not only by thickness. It's the main reason it survived.

Exactly, and of course by time. That (and the bad crimp) is the main reason for replacing it. The charge current will be the same as before but it will flow longer.

.. And of course the kind of energy. Green energy does harm cables less then the dirty grey variant... Especially energy from nuclear sources will glow up your cables earlier.

And here we have the cheap Chinese charge port relays after the same usage period. They are rated 200A while peak charge current is 125A.

It seems the quality varies, one relay looks like brand new while the other must have generated quite some heat. The contact area shows no wear at all.