Home energy · EV charging
Level 1 or Level 2: which is enough?
Enter your battery, the charge you need and how long the car is parked. See whether a 120 V cord is enough or Level 2 is worth installing.
Inputs
Starting values are illustrative, not current prices or specifications. Replace each with your own.
Result
Answer
Level 1 on 120 V adds only a few miles of range per hour; AFDC puts it at about 5 miles per hour and Level 2 at about 25. Level 1 charging needs a power outlet on a dedicated branch circuit (AFDC). Do not use extension cords or adapters for sustained charging, and have a licensed electrician check the outlet if you are unsure. Enter your parked hours and daily use to see whether the slow option covers your driving.
Worked example
A 60 kWh battery going from 20% to 80% takes in 36 kWh. With 10% losses the supply provides 40 kWh. Level 1 at 1.44 kW needs 27 h 47 min; Level 2 at 7.2 kW needs 5 h 33 min. In a 10-hour parked window, Level 1 adds 1.44 × 10 × 0.9 = 12.96 kWh (+21.6% battery, about 72 km at 18 kWh/100 km) and does not reach the target; Level 2 reaches it.
Formulas and notes
- Energy into battery = battery kWh × (target % − start %) ÷ 100; supply energy = that ÷ (1 − losses).
- Time = supply energy ÷ charger kW.
- Gain in the parked window = charger kW × hours × (1 − losses), capped at a full battery.
- Range added = energy gained ÷ energy use × 100.
- Constant power is assumed; real chargers vary, and the car's onboard charger may limit AC power.
Planning estimate only, not professional advice. Sources, checked 2026-10-08: U.S. DOE Alternative Fuels Data Center, Electric Vehicle Charging Stations · U.S. DOE Alternative Fuels Data Center, Charging Electric Vehicles at Home
FAQ
How many miles per hour does Level 1 charging add?
AFDC gives approximately 5 miles of range per hour for Level 1 (assuming 1.9 kW) and about 25 for Level 2. Your car's figure depends on its efficiency and charge power, which this calculator lets you enter.
Is Level 1 charging enough for daily driving?
AFDC says many EV owners meet daily range needs charging overnight on Level 1 if a suitable outlet on a dedicated circuit is available. Compare the range added in your parked window with your daily distance.
What is the difference between Level 1 and Level 2?
Level 1 uses a 120 V household outlet and the cord that comes with the car. Level 2 uses 240 V (208 V in many commercial buildings) and charges several times faster, but normally needs a new circuit.
Do I need an electrician for Level 2?
Yes for a new circuit. Hire a licensed electrician; see the amps and breaker size calculator for the planning numbers.
Is a Level 2 charger worth the cost?
It depends on your daily distance, your parked hours and the install quote. Use the EV home charger payback tool for the money side.