Home EV chargers usually run on 240-volt power, often called Level 2 charging. Understanding why helps you choose a charger, plan an outlet or circuit, and estimate how long a charge will take. This article explains where 240V comes from, how it compares with standard 120V power, and why it matters for charging.
Where 240V comes from
In most US homes, electricity arrives as a split-phase service. Standard outlets connect to one of two 120-volt legs, and the voltage between the two legs is 240 volts. Large appliances such as electric dryers, ranges, and water heaters use 240V circuits because they need more power than a 120V outlet can safely provide.
Power, voltage, and current
Electrical power equals voltage multiplied by current, and it is measured in watts. A kilowatt is 1,000 watts. The same amount of power can be delivered at a high voltage with low current or at a low voltage with high current. For EV charging, a 240V circuit delivers the same power as a 120V circuit with about half the current, so the wire and connections carry less current for each kilowatt they supply.
Consider two round-number examples. A 120V outlet on a 15-amp circuit can supply about 12 amps continuously, which is about 1.4 kW. That is slow for a car. A 240V circuit rated at 50 amps can supply a 40-amp continuous load, which is 240 volts multiplied by 40 amps, or 9.6 kW.
Level 1 and Level 2 charging
Level 1 charging uses a standard 120V outlet and typically adds only a few miles of range per hour. Level 2 charging uses a 240V connection and adds many more miles per hour. Most owners who charge overnight to cover a daily driving routine use Level 2, because it can replace a full day of driving in a single session.
Circuits and the 80 percent rule
A breaker is rated for the maximum current it can carry. For a continuous load such as an EV charger, the general rule is that the load may use at most 80 percent of the breaker rating. A 40-amp charger therefore needs a 50-amp circuit, and a 48-amp charger needs a 60-amp circuit. Because of those requirements, the larger charger is usually hardwired. A licensed electrician should do that work, and local permits and inspection may apply. Check with your local building department.
Estimating charging time
As a rough guide, charging time equals the battery's energy in kWh divided by the charger's power in kW, before losses. A 75 kWh battery at 9.6 kW takes roughly 8 hours from empty. Your car's onboard charger may limit how fast it accepts AC power, so the real time can be longer than the simple calculation.
How this applies to EVIQO chargers
EVIQO chargers are 240V units with a 25 ft cable. The 40A (9.6 kW) models need a 50A circuit, and the 48A (11.5 kW) models need a 60A circuit and must be hardwired. The 40A option adds about 38 miles of range per hour of charging, and the 48A option adds about 46 miles per hour. Each EVIQO charger comes with a 3-year warranty, and a 4-year extended warranty is available for an additional charge.