EV charger glossary

EVSE (Electric Vehicle Supply Equipment) — the wall-mounted box people call a charger. It supplies AC power and manages the safety handshake; the AC-to-DC conversion happens in the vehicle. Onboard charger — the vehicle's internal unit that sets the maximum AC charging rate your car can accept, regardless of how big the wall unit is.

Level 1 — charging from a standard 120-volt outlet, about 1.9 kW, roughly 2 to 5 miles of range per hour. Level 2 — 240 V (or 208 V) charging at roughly 7.2 to 19.2 kW, about 10 to 25 miles of range per hour depending on the source and the equipment. DC fast charging — up to 500 kW, roughly 100 to 200-plus miles in 30 minutes; a public-infrastructure product, not a residential one.

kW vs kWh — kW is how fast energy moves (the charger's rating); kWh is how much energy you used (what your utility bills). A 7.2 kW charger running for one hour delivers about 7.2 kWh. Continuous load — the NEC classification applied to EV charging infrastructure, which affects how the circuit and overcurrent protection are sized relative to the equipment's rated current.

NEC Article 625 — the National Electrical Code article containing most of the provisions applicable to EV charging equipment. Hardwired vs plug-in — whether the unit is permanently wired to the circuit or connects via a receptacle; $850–$1,800 versus $1,000–$2,200 including labor. Time-of-use rate — a utility pricing plan where electricity costs less at off-peak hours, which AFDC notes some utilities offer to charging equipment owners.

How to choose

Learn 'onboard charger' first

It explains most disappointment about charging speed and stops you overbuying amperage.

Don't mix up kW and kWh

Salespeople sometimes do. kW is the rate; kWh is what you pay for.

Recognize 'continuous load' as a real constraint

It's why the breaker is larger than the charger's rating. An electrician who can't explain it is a concern.

Ask which connector standard your car uses

Connector compatibility is a hardware decision that's expensive to get wrong.

Ask your utility what 'time-of-use' would mean for you

AFDC notes some utilities offer these rates to charging equipment owners. It's a free question with a possibly large answer.