An Old NACS Adapter Melted on a Rivian R2. Check Yours Before CCS Fast Charging
State of Charge's Tom Moloughney melted a pin on an older Tesla CCS-to-NACS adapter while DC fast-charging a Rivian R2 — a 400-volt, high-amperage reality check for anyone carrying early adapters to Electrify America and ChargePoint.
COLORADO SPRINGS — Native NACS on the Rivian R2 sounds like the adapter problem is over. It is not. Superchargers are easy. CCS stations still want a bridge, and some bridges cannot take the heat.
During a real-world DC fast-charging test covered by InsideEVs, State of Charge host Tom Moloughney used an older Tesla CCS1-to-NACS adapter on an R2. A DC pin on the CCS side melted. The session finished, but the hardware was cooked. That is not a Rivian software glitch. It is what happens when a 400-volt EV pulls sustained high amperage through an early adapter that never learned to throttle.
Rivian kept a 400-volt architecture on the cheaper R2 instead of jumping to 800-volt systems common on some rivals. To keep charge times competitive, the car can draw more than 600 amps for long stretches when the station can deliver it. AutoGuide and other coverage put continuous draws near 630 amps in that class of session. Older adapters without modern thermal sensing keep accepting that current until plastic and metal give up.
Newer adapters behave differently. Units with thermistors and UL 2252-style safety design can tell the car or station to derate when the housing gets hot. Moloughney's follow-up with a Lectron adapter — Rivian's supplier for its branded unit — triggered thermal derating on the vehicle screen instead of melting. That is the failure mode you want: slower charge, intact hardware.
If your R2 lives in a CARB state, Rivian includes the CCS adapter in the vehicle price (you may still need to add it in the configurator). Elsewhere, buy the Rivian-branded adapter or a current Tesla / UL 2252-certified unit. Do not dig out the Amazon special from 2023 or the first-generation Tesla adapter you borrowed for a Model Y road trip.
This is not only a Rivian story. Coverage notes other 400-volt, high-amp EVs from Tesla, BMW, and Polestar can also stress weak adapters when the station is willing. Asian American and Asian Canadian households buying a first highway EV often inherit adapters from relatives or leftover Tesla kits. Ask what year the adapter is from before you plug into a Walmart CCS stall at 95% power.
For trip planning, start with our road trip charging networks: NACS vs CCS guide and the public vs home charging calculator. If condo or workplace charging is the weekday plan, keep public EV charging etiquette and reliability bookmarked too.
The R2's NACS port is a gift at Superchargers. On the CCS map, your adapter is part of the powertrain. Treat it like one.