A standard 120-volt outlet adds between 3.4 and 5.5 miles of range per hour to the 15 US-rated cars here — 34 to 55 miles from a ten-hour night. That covers the average American day of 37 miles for every car in the table, and a full charge from 10 per cent takes 55 h 35 min to 80 h 26 min.
Every car on a household outlet
Level 1 is the cable that comes in the boot: it plugs into an ordinary 15-amp outlet and draws 12 amps, the most a 15-amp circuit may carry continuously under US electrical code. At 120 volts that is 1.44 kW at the wall. The EPA’s kilowatt-hours per 100 miles is also measured at the wall, so dividing one by the other gives miles per hour with charging losses already inside the number — the same method as 7.7 kW against 11.5 kW, whose figures appear in the last column for comparison.
| Car | EPA kWh / 100 mi | Miles per hour | Overnight (10 h) | 10 → 100% | On 7.7 kW |
|---|---|---|---|---|---|
| Hyundai Ioniq 6 Long Range RWD | 26.0 | 5.5 | 55 | 55 h 35 min | 30 |
| Tesla Model 3 Long Range AWD | 26.4 | 5.5 | 55 | 57 h 5 min | 29 |
| Tesla Model Y Long Range AWD | 27.5 | 5.2 | 52 | 56 h 12 min | 28 |
| Toyota bZ4X AWD 73.1 kWh | 28.0 | 5.1 | 51 | 50 h 24 min | 27 |
| BMW i4 eDrive40 | 28.5 | 5.1 | 51 | 59 h 19 min | 27 |
| Volvo EX30 Single Motor Extended Range | 29.2 | 4.9 | 49 | 47 h 38 min | 26 |
| Kia EV6 84 kWh RWD | 29.6 | 4.9 | 49 | 59 h 1 min | 26 |
| Volkswagen ID.4 Pro | 29.8 | 4.8 | 48 | 54 h 12 min | 26 |
| Hyundai Ioniq 5 84 kWh RWD | 30.0 | 4.8 | 48 | 59 h 38 min | 26 |
| Ford Mustang Mach-E Extended Range RWD | 30.7 | 4.7 | 47 | 61 h 24 min | 25 |
| Ford Mustang Mach-E Standard Range RWD | 31.4 | 4.6 | 46 | 51 h 1 min | 25 |
| Nissan Ariya e-4ORCE 87 kWh | 36.6 | 3.9 | 39 | 62 h 13 min | 21 |
| Porsche Taycan (rear-wheel drive) | 37.1 | 3.9 | 39 | 63 h 32 min | 21 |
| Kia EV9 99.8 kWh AWD | 40.0 | 3.6 | 36 | 70 h 45 min | 19 |
| Rivian R1T Dual Motor, Large pack | 42.9 | 3.4 | 34 | 80 h 26 min | 18 |
The order is the efficiency ranking of the database, because the wall delivers the same 1.44 kW to every car and efficiency decides how far each kilowatt-hour goes. The Hyundai Ioniq 6 Long Range RWD turns it into 5.5 miles an hour; the Rivian R1T Dual Motor, Large pack, at 42.9 kWh per 100 miles, into 3.4.
Is it enough?
For a commute, usually. The average US car covers about 13,500 miles a year — 37 a day — and the slowest car here replaces that in 11 h 1 min of charging, the quickest in 6 h 41 min. A car that is home ten hours a night stays topped up on Level 1 alone as long as the daily distance stays under its overnight figure in the table. What Level 1 cannot do is recover from a long day: a Volkswagen ID.4 Pro that arrives home nearly empty needs 54 h 12 min to fill, which is most of a working week of nights. That is the case for a 240-volt circuit, and the 7.7 kW post works out which of the two common sizes is worth paying for.
Cold weather cuts both ways. Below freezing the pack needs energy to warm itself before it accepts charge, and on a 1.44 kW supply a meaningful share of the night can go to heating rather than range; the per-hour figures here are for a car in a garage above about 10 °C. Winter range itself is a separate subject — do electric cars lose range in cold weather has the measured losses.
Cost is the same, speed is not
A kilowatt-hour costs what your tariff says regardless of how fast it arrives, so Level 1 does not make a mile cheaper or dearer than Level 2 — the monthly figures in what it costs to charge an EV per month and by state apply unchanged. The one caveat is that a portable Level 1 cable spends a slightly larger share of its energy on the car’s own electronics because the session is longer; the EPA figure absorbs some of that, not all of it.
Frequently asked questions
How many miles per hour does a 120 V outlet add?
Between 3.4 (Rivian R1T Dual Motor, Large pack) and 5.5 (Hyundai Ioniq 6 Long Range RWD) across the 15 EPA-rated cars here, from 1.44 kW at the wall divided by each car’s EPA energy use per mile.
How long does it take to fully charge an EV on Level 1?
From 10 to 100 per cent, 55 h 35 min for the Hyundai Ioniq 6 Long Range RWD and 80 h 26 min for the Rivian R1T Dual Motor, Large pack. Nobody does this in one session; the practical question is whether one night covers one day, and for the average 37-mile day it does for every car in the table.
Can I charge an electric car on a normal outlet every day?
Yes, provided the outlet is on its own circuit in good condition — a 12-amp continuous draw for ten hours is more than most household sockets ever see, and a worn outlet or a shared circuit is a heat problem. A dedicated outlet, or the 240-volt circuit that a Level 2 charger needs anyway, removes the concern.
Is Level 1 charging bad for the battery?
No. Slow charging is the gentlest thing a lithium-ion pack experiences; heat and high current, not low current, are what age cells. The chemistry behind that is in how EV batteries actually age.
Sources
EPA combined energy use and range: fueleconomy.gov, model year credited on each car’s page. Circuit loading: US National Electrical Code continuous-load rule (80 per cent of the breaker rating). Annual mileage: the standing US assumption on the methodology page. Per-hour figures are 1.44 kW divided by the unrounded EPA energy use per mile; times are rounded to the minute.