Choosing the Right EV Charger Amperage

CHOOSING THE RIGHT EV CHARGER AMPERAGE
Quick Guide to Match Power, Panel Capacity, and Future Needs

INTRODUCTION
Amperage dictates charging speed and influences breaker size, wiring gauge, and permit cost. Level 2 chargers for North American homes typically range from 16 to 80 amps. Use the steps below to pick the correct rating for your vehicle and electrical panel.

1. CHECK VEHICLE ACCEPTANCE RATE
   Most EVs accept 32 amps or 48 amps on AC. Confirm the spec sheet before buying a charger larger than the car can use.

2. AUDIT SERVICE PANEL CAPACITY
   a. Find main breaker rating, usually 100 A or 200 A.
   b. Add up existing 240-volt loads such as HVAC and electric range.
   c. Ensure at least 40 A spare headroom for a 32-amp charger or 60 A for a 48-amp charger.

3. MATCH CHARGER TO BREAKER
   NEC rule: continuous loads must not exceed 80 percent of breaker rating.
   32 A charger needs a 40 A breaker and 8-gauge copper.
   48 A charger needs a 60 A breaker and 6-gauge copper.

4. CONSIDER DAILY DRIVING PATTERN
   Average US commute is 30 miles. A 32 amp charger replenishes that range in about two hours. Choose 48 amps if you drive long distances, share the charger with another EV, or need rapid top-ups.

5. FUTURE-PROOFING
   Battery capacities increase every model year. If the budget allows, install wiring and breaker sized for 48 amps now, even if you dial the charger down to 32 amps until you buy a bigger vehicle.

COMMON QUESTIONS
Will a high-amp charger hurt my battery?
No. The onboard charger in the vehicle limits intake to a safe level.
Can I place a 48-amp charger on a 40-amp breaker?
No. Code requires a 60-amp breaker for a 48-amp unit.
What if my panel is full?
Load-shedding devices, a sub-panel, or a full service upgrade are the standard solutions.