NACS, which stands for North American Charging Standard, is the connector Tesla developed for its vehicles. It is also published as SAE J3400. Many other automakers have announced plans to adopt it, so the NACS connector is becoming more common on electric vehicles sold in North America. If you are choosing a home charger, this article explains what NACS is and how it affects your decision.
What the NACS connector is
NACS is a compact connector that handles both AC charging, used at home and at destinations, and DC fast charging, used at high-power stations, through one plug. That combination is the main difference from the J1772, which covers AC charging only. The NACS plug is smaller than a J1772 plug, and the port on the vehicle is smaller too.
Why the connector is changing
For many years, Tesla vehicles used a proprietary connector, while most other electric vehicles in North America used the J1772 for AC charging and a separate connector for DC fast charging. Owners of vehicles with different ports often needed adapters to use some public chargers. Tesla made the design available to other manufacturers, and many automakers have since announced plans to offer NACS ports on future vehicles. The timing differs from one manufacturer and model to the next, so the connector on your car depends on its model and model year.
What stays the same for home charging
NACS changes the plug, not the electrical rules. Level 2 home charging still runs on a 240-volt circuit, and the car's onboard charger still limits how fast the car accepts AC power. A 40 amp charger delivers about 9.6 kW before losses, and a 48 amp charger delivers about 11.5 kW. Charging time is roughly the battery capacity in kilowatt-hours divided by the charger's power, so a 75 kWh battery charged at 9.6 kW takes roughly 8 hours from empty.
The circuit rules also stay the same. A 40 amp NEMA 14-50 plug-in charger needs a 50 amp circuit, since a continuous load may use at most 80 percent of the breaker rating. A 48 amp hardwired charger needs a 60 amp circuit and must be installed by a licensed electrician. Local permits and inspection may apply, so check with your local building department.
Adapters and mixed households
If your car has a J1772 inlet and your charger has a NACS cable, or the reverse, an adapter may connect the two. An adapter changes the shape of the plug and nothing else. The current limit is still set by the charger, the cable, and the circuit, and the lowest rating in the chain controls the charging speed. The article on using EV charging adapters at home covers those limits in more detail.
How this applies to EVIQO chargers
EVIQO sells two NACS chargers. The 48 amp hardwired model is rated for 11.5 kW and adds about 46 miles of range per hour of charging. The 40 amp NEMA 14-50 plug-in model is rated for 9.6 kW and adds about 38 miles per hour. Both come with a 25 ft cable and a 3-year warranty, and a 4-year extended warranty is available for an additional charge. If you choose the plug-in model, plan for a NEMA 14-50 outlet on a 50 amp circuit. The hardwired model needs a 60 amp circuit and a licensed electrician.