Charging an electric car at home is the cheapest fuelling most people will ever do, and it is also the largest new load most houses have added in a generation. Both things are true at once, which is why the bill goes up and the total cost of driving goes down.
A Level 2 home charger delivers about 7,200 W, costing [hed_cost appliance=”ev-charger” period=”hour”] per hour of charging at [hed_var key=”us_rate_cents” format=”cents”] per kWh. A typical overnight session of four hours adds roughly 29 kWh and costs [hed_cost appliance=”ev-charger” period=”day”]. Charging 12,000 miles a year at around 3.5 miles per kWh works out to about 630 dollars annually at the national average rate, against roughly 1,600 dollars of gasoline for a 28 mpg car at 3.75 a gallon.
Level 1, Level 2, and why speed is not price
Level 1 charging on a standard 120 V outlet delivers about 1,400 W, or three to five miles of range per hour. It is slow but it costs exactly the same per kWh as Level 2, because a kilowatt-hour is a kilowatt-hour. Level 2 is faster, not cheaper.
Level 2 units are commonly 7.2 kW on a 40 A circuit, or 11.5 kW on a 60 A circuit. The car decides how much of that it will accept; many vehicles cap onboard AC charging at 7.2 or 9.6 kW regardless of what the charger can supply. Installing an 11.5 kW unit for a car that accepts 7.2 buys nothing.
Charging is also not perfectly efficient. Expect to pay for roughly 10 percent more energy than reaches the battery, lost as heat in the onboard charger and cables. Cold weather adds more, because the car heats the battery before and during charging.
[hed_wattage_matrix appliance=”ev-charger”]Cost by charging session length
[hed_hours_matrix appliance=”ev-charger” hours=”1,2,4,6,8,10″]The one appliance where time of use really pays
An EV is the best time-of-use load a household can have, because you genuinely do not care when it charges as long as it is done by morning. Many utilities offer EV-specific rates with overnight prices well below the standard tariff, sometimes a third of the daytime rate.
Scheduling is set in the car, in the charger app, or both. Set it in one place only; conflicting schedules between vehicle and charger are the most common reason people wake up to an uncharged car. Our time-of-use EV charging calculator shows what the shift is worth on your tariff.
[hed_rate_matrix appliance=”ev-charger”]EV charging cost by state
Four hours of Level 2 charging, roughly 100 miles of range, in every state.
[hed_state_costs appliance=”ev-charger”]Circuit size and whether your panel can take it
A 7.2 kW charger on a 40 A circuit is a continuous load, which under electrical code must not exceed 80 percent of the breaker rating. That is why a 7.2 kW unit needs a 40 A breaker rather than a 30 A one, and why the wire size matters.
The other question is whether your panel has room. A 200 A service with electric heating, an electric range and a water heater may not have the headroom for a 60 A charger circuit without a load calculation. Options include a smaller charger, a load-management device that throttles charging when the house draws heavily, or a service upgrade. The EV charger circuit estimate calculator and the whole-home load calculator cover the arithmetic.
How this compares to everything else you plug in
Per hour against the other large circuits in the house. The charger is the biggest, which is why panel capacity comes up so often.
[hed_compare_table appliances=”ev-charger,electric-water-heater,clothes-dryer,central-air-conditioner,electric-oven,space-heater”]Questions people actually ask
[hed_faq]How much does it cost to charge an EV at home?About [hed_cost appliance=”ev-charger” period=”hour”] per hour on a 7.2 kW Level 2 charger at the US average rate. A full charge of a 60 kWh battery costs roughly 11 dollars, giving around 200 miles.
Is it cheaper to charge at home or at a public charger?Home is almost always cheaper, often by half or more. Public DC fast charging carries a premium for the equipment and the speed. Home charging on an overnight time-of-use rate is cheaper still.
How many watts does a Level 2 EV charger use?Commonly 7,200 W on a 40 A circuit, ranging from 3,300 W for a low-power unit to 11,500 W on a 60 A circuit. The car may accept less than the charger can deliver.
Does charging an EV overnight save money?Only if you are on a time-of-use or EV tariff. On those plans the overnight rate can be a third of the daytime rate, which is a large saving on a load this size. On a flat rate the timing changes nothing.
How much will an EV add to my electricity bill?Around 50 dollars a month for 1,000 miles of driving at the US average rate and typical efficiency. That is the number to compare against what you were spending at the pump, not against your old electricity bill.
Is Level 1 charging cheaper than Level 2?No. Per kilowatt-hour they cost the same. Level 1 is slightly less efficient over a long slow charge because the car overheads run for longer, so if anything it is marginally more expensive.[/hed_faq]
Related running costs
[hed_related appliances=”electric-water-heater,clothes-dryer,central-air-conditioner,heat-pump”]Running it on solar
A level 2 ev charger uses [hed_daily_energy appliance=”ev-charger”] a day, which needs about [hed_panels_needed appliance=”ev-charger”] standard 400 W panels. Full array, battery and inverter sizing is on how many solar panels to run a level 2 ev charger.