I've never paid by the minute. Tesla Superchargers often deliver less energy per minute when they're busy (sometimes much less!) and it would be frustrating if they charged per-minute.
Other systems I've seen (Chargepoint) also seem to be energy-based.
The Supercharger network is well done. It's a shame that they took this long to open up to other car models because they really do get a lot of things right.
Careful. Some superchargers will now charge you extra per minute as soon as you cross 80% capacity (regardless of your charge limit).
Does this also apply to non-Teslas? I'm guessing there's a bit of two-way communication from car to charger, for authentication/billing purposes but also for congestion fees like charging beyond 80%. Does the app notify you to take your car off the charger?
I understand the reasoning but sympathize with the luddites who shun all this technology. Imagine going on a road trip with your EV, stopping for a bite to eat and refresh while putting your car on the charger. Maybe there was a long line or you needed a long bathroom stop, so your car sits at the charger "too long" and you get a nice penalty.