Do the older Tesla-connector Superchargers use the same protocol as the newer NACS-connector Superchargers? I read somewhere that older Teslas might need a "CCS upgrade" in order to use NACS chargers (except, I'm guessing, if the new NACS station also supports the old Tesla protocol). Is that possible? Seems very awkward if so - like stupid USB3, you never know what is going to work, despite the plug fitting, until you try it.
I believe you're operating under some misapprehensions. The term NACS ("North American Charging Standard") is the name that Tesla applied, retroactively, to the Tesla plug they'd been using for a decade, since the introduction of the Model S. Although the name "NACS" was introduced about half a year ago, the plug itself hasn't changed. That is,
all North American Superchargers use NACS -- even those Superchargers built before Tesla invented the acronym "NACS."
The CCS upgrade to which you refer relates to something different, although there are some peripheral connections. Because Europe standardized on CCS2 (which is electronically compatible with the CCS1 we use in North America, but with a somewhat different physical plug), Tesla added CCS
protocol support to its vehicles starting whenever Tesla started selling the Model 3 in Europe; however, the charging controller is different in European than in North American Teslas, and IIRC, the CCS protocol support took a while to trickle down to North American Teslas. This appeared in late 2020 in the US, IIRC.
Tesla's NACS documentation is about the
physical connectors. AFAIK, it says nothing about the communications protocols, and strongly implies that those protocols should be the CCS protocols. Thus, when (because I think it's now inevitable) the current CCS charging providers start adding native NACS plugs, they're likely to use the CCS communications protocols, not the Tesla communications protocols. (Caveat: It's conceivable that Tesla is negotiating with these network providers right now to open up or license its communications protocols, so this may be completely wrong.) Therefore, if you own an older Tesla and don't get the CCS protocol upgrade, you won't be able to charge with these future NACS plugs at non-Tesla DC fast chargers. Note that EVgo currently offers NACS plugs via Tesla's CHAdeMO-to-NACS adapters, so those stations will be exceptions to this rule, for however long they continue to exist and work. This is all the more reason to get this upgrade, IMHO. It's currently available for Model S and Model X, and it should be available for Model 3 and the few Model Y vehicles that need it. (Somebody on this forum posted that Tesla said it would be available on July 1, but take that with a huge grain of salt.)
It's my understanding (but I may be wrong) that the older V2 Superchargers can use Tesla's protocols, but they lack support for the CCS communications protocols. At least in part because of Europe's standardization on CCS, though, Tesla added this support to the V3 Superchargers. That's what makes Tesla's Magic Dock CCS1 support possible, from a communications point of view. The V3 Superchargers do still support the original Tesla communications protocol, though -- older non-CCS vehicles can charge on V3 Superchargers, after all.
I am aware that in CCS2 regions, some older Teslas needed CCS port upgrades but that included the physical plug socket (?).
As I understand it, this upgrade involved a circuit board swap and adapter that's conceptually similar to what Tesla is now offering for S/X owners; however, CCS2 is physically different from CCS1, and Tesla never used what's now called NACS in Europe. Thus, the adapter is physically different. I don't know if those older S/X cars used the same circuit board in North America and Europe, and I don't believe they do today, so the exact components in that upgrade are different. AFAIK, the European upgrade does
not change the physical charge port on the car. As noted, it's needed only on older Model S and Model X; starting with the Model 3, Tesla shipped European vehicles with CCS2 charge ports.
