A Level 1 charger normally draws 12 amps. That is the continuous current allowed on a standard 15-amp, 120-volt household circuit in North America. Some Level 1 chargers can draw up to 16 amps, but only on a 20-amp circuit built for it. The setting belongs to the circuit, not to the charger’s maximum label.
Key Takeaways
- Most Level 1 chargers draw 12 A continuously on a 15 A, 120 V circuit.
- Up to 16 A is possible only on a 20 A circuit, because continuous loads are sized at 125%.
- That works out to about 1.4-1.9 kW, or roughly 2-5 miles of range per hour.
- Always set an adjustable charger to the circuit, never to the charger’s maximum.
The Numbers in One Table
| Circuit | Continuous draw | Power (amps x volts) | Typical result |
|---|---|---|---|
| 15 A, 120 V | 12 A | About 1.4 kW | Standard Level 1 charging |
| 20 A, 120 V | 16 A | About 1.9 kW | Faster end of Level 1 |
| Level 1, typical figure | Varies | About 1 kW | 2-5 miles of range per hour (U.S. DOT) |
The DOT figure is a planning average across cars and conditions; the table’s arithmetic shows what your circuit can deliver. Our guide to how many amps an EV charger needs puts these figures next to Level 2 requirements.
Why 12 Amps and Not 15?
EV charging is a continuous load: it runs at full current for three hours or more. Under the National Electrical Code approach, a continuous load is sized at 125%, so the breaker must be bigger than the charger’s draw. Work it backwards and a 15-amp breaker supports 12 amps of charging, while 16 amps needs a 20-amp breaker. Drawing 15 amps for ten hours from a 15-amp circuit is exactly what the rule exists to prevent. If you are unsure what a circuit can carry, our article on whether a Level 1 charger needs a dedicated circuit explains the checks.
How Many kW Is a Level 1 Charger?
Multiply amps by volts. At 12 amps and 120 volts you get about 1.4 kW; at 16 amps, about 1.9 kW. That is the whole answer, and it explains Level 1’s reputation: even the strongest household setup delivers under 2 kW, against 7 to 19 kW for Level 2. Some energy is also lost as heat during charging, so the battery gains slightly less than the arithmetic suggests. For the energy side of the same sums, see how many kWh it takes to charge an EV.
How Many Miles Does That Add Per Hour?
The U.S. DOT puts Level 1 at roughly 2 to 5 miles of range per hour plugged in. Over a ten-hour night, that is about 20 to 50 miles, which covers many daily commutes but will not refill a large battery from empty. Efficient cars sit at the top of the range; heavy vehicles and cold weather sit at the bottom. Treat the figure as a guide for planning, not a guarantee for a specific car.
Setting an Adjustable Charger Correctly
- Find the circuit rating first: check the breaker in the panel, not the charger’s packaging.
- Set the charger at or below the continuous figure: 12 A on 15 A, 16 A on 20 A.
- If anything else shares the circuit, step down or move to a dedicated circuit.
- Warm plugs, nuisance trips or flickering lights mean stop and have the circuit checked.
If 12 to 16 amps is not enough and a proper 240-volt circuit is available, an adjustable portable Level 2 unit is the natural upgrade. The EV-ACS3210T portable charger adjusts from 10 to 32 A in six steps and delivers about 7.7 kW at full setting, with IP66 protection. Match the setting to the new circuit in the same way: the circuit decides, the charger follows.
Frequently Asked Questions
Can I set my Level 1 charger to 16 amps on any outlet?
No. Sixteen amps continuous needs a 20-amp circuit, including the right breaker and wiring. On a 15-amp circuit, stay at 12 amps.
Why does my charger only show 8 or 10 amps?
Some cars and cables default to a lower setting, and some let the driver choose. A lower default is a safety margin for unknown outlets; raise it only when you know the circuit rating.
Is 12-amp charging bad for the battery?
No. Slow charging is gentle on the battery. The limit is time, not battery health: Level 1 simply adds range slowly.
Related Reading
- Can I Plug a Level 1 Charger Into a 240V Outlet?
- Does Level 1 Charging Use More Electricity Than Level 2?
- Is Level 1 Charging Bad for Your Battery?
- How Many kW Is a Level 2 Charger?
