40-amp vs 48-amp EV charger: which is enough?
Compare real-world charging speed, circuit requirements, and the situations where the extra output matters.
Bottom line: A 40A charger is enough for most overnight charging. Choose 48A when your vehicle can accept it, you regularly need to replace substantial energy in a short overnight window, and your electrical system can support the required hardwired circuit.
At-a-glance comparison#
| Charger output | Approx. power at 240V | Typical circuit basis | Best fit |
|---|---|---|---|
| 40A | 9.6 kW | 50A circuit | Most overnight charging and plug-in flexibility |
| 48A | 11.5 kW | 60A circuit | High daily mileage and shorter charging windows |
How much faster is 48A?#
A 48A charger delivers about 20% more power than a 40A charger when the vehicle can accept the full rate. If a 40A session would take 10 hours, the same energy could take roughly 8 hours 20 minutes at 48A. In daily use, both may finish well before morning.
Choose based on energy, not the badge#
Estimate the energy you need to replace after a normal day and divide it by charger power. Also check the vehicle’s maximum AC acceptance rate: a vehicle that accepts less than 9.6 kW will not charge faster on a 48A unit.
When to choose each#
Choose 40A when: overnight is a generous charging window, your vehicle cannot use more, or a suitable 50A circuit already exists.
Choose 48A when: you drive far most days, have a shorter off-peak window, and are already planning a compatible hardwired installation.
Ready to choose your charger?#
Compare the chargers that fit your home, vehicle, and installation plan.
Common questions#
It is worth considering if your vehicle can accept 11.5 kW and the shorter charging window has practical value. Otherwise, the added installation capacity may not improve daily use.
Yes. The vehicle and charger negotiate the charging rate, so the car draws only what it can accept, assuming the equipment is correctly installed and configured.
A 48A continuous load is generally installed as a hardwired charger on a 60A circuit in the United States. Always follow the product instructions and local requirements.