[i-am-gizm0]

At least on AC Level 1/2 charging (using just a J1772 port) the signalling is pretty rudimentary if I remember correctly. Something along the lines of the car puts out a square wave on one of the signalling pins and based on the resistance it sees it knows whether it's plugged in and how much power it can charge, so there isn't much room (dare I say any) way to interact much with the car through that port. I don't know how DC charging works but I assume there's a little bit more smarts to it. Tesla on the other hand is a completely different story.

[rtkwe]

The really high voltage fast chargers as far as I understand them connect directly to the battery bypassing the cars battery charger to directly charge the battery not sure how much communication there is on those channels though.

[vegardx]

You're probably thinking about the on-board inverter, it's often referred to as a battery charger. The battery management system is entirely within the car, and the car will tell what voltage and amperage to deliver to it.

The design of CCS2 is actually quite nice. There are pins for singalling that, if broken, will immediately shut down power delivery. This means that you can just pull the cable out safely, without risking arcing or electrocuting yourself.

[rtkwe]

My understanding was it also bypassed the BMS but I may have confused what they were saying it's been a minute.

[rlpb]

When I've done DC rapid charging on my Leaf, I noticed that the charger knew the battery percentage reported by the car. That seems likely to be digital signalling to me, so suddenly there's the risk of buffer overflows and suchlike.

I've not seen this on AC, but when I looked into this previously I got the impression that there exists a digital signalling protocol established by modulating something ignored by older cars and chargers that can be optionally supported. If that's the case then there's potentially attack surface there, too.

[fnordpiglet]

That’s why I only buy cars written in rust.

[dylan604]

brings new meaning to the term "rust bucket"

[em-bee]

you must be a fan of oldtimers then. since most new cars are made with stainless steel, aluminum, carbon fiber or and other materials.