Level 2 Charger Amperage Chart

The Level 2 Charger Amperage Chart maps each amperage setting to the power, range per hour, and charge time it delivers on a 240-volt circuit.

From Amps to Kilowatts

Every Level 2 charging speed starts from one equation: power in kilowatts equals the supply voltage multiplied by the current in amps, divided by 1,000. A 32-amp charger on a 240-volt circuit delivers 32 times 240, or 7,680 watts, which is the 7.7 kW figure printed on the unit. Raise the current and the power rises with it, because the voltage on a home circuit barely moves.

Two adjustments separate that label from what the battery actually receives. The first is conversion loss: the onboard charger turns wall AC into the direct current the pack stores, and roughly 10% is shed as heat along the way, so a nominal 7.7 kW puts about 6.9 kW into the cells. The second is voltage sag, because a residential 240-volt supply is a nominal figure that often sits nearer 230 to 238 volts under load, trimming delivered power a few percent below the nameplate. Both effects are why the chart below pairs each amperage with a real-world range per hour rather than the headline kilowatts alone, and why how an onboard-charger rating reads on a spec sheet is worth a look for the surrounding terminology.

Level 2 Amperage Comparison Chart

The table below is the heart of the tool. Each row takes a common Level 2 current at 240 volts and reports the nominal power, the real-world range added per hour for a 250 Wh/mi sedan, and the time to move a representative 60 kWh battery from 20% to 80%. Read down the power column to see how amperage scales, and down the time column to see what each step buys in a typical overnight window.

Amperage (240V)	Delivered Power	Range Added per Hour	Time 20% to 80% (60 kWh)
16 A	3.8 kW	14 mi/hr	10 h 25 m
24 A	5.8 kW	21 mi/hr	6 h 57 m
32 A	7.7 kW	28 mi/hr	5 h 13 m
40 A	9.6 kW	35 mi/hr	4 h 10 m
48 A	11.5 kW	41 mi/hr	3 h 28 m
80 A	19.2 kW	69 mi/hr	2 h 05 m

Two patterns stand out. Power and range climb in direct proportion to amperage, so a 48-amp charger adds range three times faster than a 16-amp one. Charge time falls on the same curve, with a floor set by the car: the figures assume the vehicle can accept the listed power, which holds through 48 amps for most modern EVs and only at 80 amps for a small set of trucks and large SUVs. To turn any row into a running fuel cost, translate the energy added into a running cost per mile against your own electricity rate.

Your Car's Onboard Charger Sets the Ceiling

Amperage describes what the charger can push; the onboard charger describes what the car will pull. Every EV carries an onboard charger that converts AC to DC, and its rating is a hard ceiling on Level 2 speed. The car always draws the lower of the two figures, so the rule that governs every cell in the chart is the minimum of supply power and onboard capacity.

That single rule trips up a lot of first-time buyers. An onboard charger rated at 11.5 kW accepts no more than a 48-amp draw at 240 volts; feed it from an 80-amp circuit rated for 19.2 kW and the car still takes 11.5 kW and ignores the rest. Upgrading the charger past that point adds cost and circuit size without adding a single mile per hour. The same logic in reverse explains why a Nissan Leaf with a 6.6 kW onboard charger gains nothing from anything above a 32-amp setting.

This is the one number worth checking before you size anything else. Once you know that onboard limit, you can match the current to your panel and daily mileage, and for the wider context, where Level 2 fits among the three charging levels places amperage inside the full Level 1, 2, and DC picture.

Why 240V, 230V, and 208V Do Not Charge Alike

The same charger plugged into different supplies delivers different power, because the voltage half of the equation changes. A North American home runs a 240-volt split-phase supply, the basis for every figure in the chart above. Commercial and workplace buildings, though, are often wired for 208-volt three-phase power, where the line-to-line voltage is lower.

The gap is larger than it looks. A 32-amp charger that delivers 7.7 kW at 240 volts drops to 32 times 208, or 6.7 kW, on a 208-volt feed, a 13% reduction that stretches every charge time to match. European single-phase supplies sit near 230 volts, between the two. None of this changes the amperage on the dial; it changes what that amperage is worth, which is why a workplace charger can feel slower than the identical unit at home.

Worked Example: An 80-Amp Charger on an 11.5 kW Car

A driver is pricing an 80-amp (19.2 kW) hardwired charger for a Tesla Model 3 Long Range, whose spec sheet lists an 11.5 kW onboard charger. The question is whether the bigger unit charges the car faster than a cheaper 48-amp one.

At 240 volts an 80-amp charger could supply 80 times 240, or 19.2 kW, but the onboard charger accepts at most 11.5 kW, so delivered power is the lower figure of 11.5 kW. After the roughly 10% conversion loss the pack sees about 10.35 kW, so a 75 kWh battery from 20% to 80% (45.0 kWh) takes 45.0 divided by 10.35, about 4 hours 21 minutes, adding close to 41 miles of range per hour. A 48-amp charger produces exactly the same numbers, because it already reaches that 11.5 kW ceiling.

The extra 32 amps of headroom never reach the battery on this car. The faster unit only earns its price on a vehicle whose onboard charger can accept more than 11.5 kW, such as a Ford F-150 Lightning at 19.2 kW with its high-power charger.

Worked Example: When a Higher Amperage Actually Helps

The same 75 kWh Model 3 sits on a 32-amp plug-in charger, and the owner is weighing a 48-amp hardwired unit. Here the 32-amp supply sits below the onboard ceiling, so there is room for more current to matter.

At 240 volts the 32-amp charger delivers 32 times 240, or 7.7 kW, comfortably under the 11.5 kW onboard limit, so the car draws the full amount. After losses the pack sees about 6.9 kW, so 45.0 kWh from 20% to 80% takes 45.0 divided by 6.9, about 6 hours 31 minutes, near 28 miles per hour. Stepping up to a 48-amp unit lifts delivered power to the 11.5 kW ceiling and cuts the same charge to about 4 hours 21 minutes.

Because the 32-amp setting sits below the onboard ceiling, every extra amp converts straight into a faster charge, and the upgrade saves more than two hours per full session. The gain stops at the moment delivered power meets the cap, which is the line the chart and the calculator both draw. For a single locked-in answer with one car and one charger, run a single-vehicle charging-time estimate.

Onboard Charger

The onboard charger is the AC-to-DC converter built into every electric vehicle, and its rating in kilowatts is the ceiling on Level 2 charging speed. Common values are 7.4 kW, 11 kW, 11.5 kW, and 19.2 kW, set by the manufacturer and unrelated to the battery size. Because Level 2 power passes through it, the onboard charger, not the wall unit, usually decides how fast a car charges at home.

Continuous Amperage

Continuous amperage is the current a charger draws steadily for the length of a session, and it is the figure that sets delivered power. A unit described as a 48-amp charger draws 48 amps continuously and delivers 11.5 kW at 240 volts. It is the charger's own rating, separate from the higher short-term current a circuit might briefly tolerate, and it is the number this chart uses on every row.

Delivered Power

Delivered power is the kilowatts that actually reach the vehicle, the smaller of what the charger supplies and what the onboard charger accepts. It is the single value that drives both charge time and range per hour on this page. When the supply sits below the onboard ceiling, delivered power equals the supply; once it climbs above the ceiling, delivered power flattens out and extra amperage stops counting. To organise the same charge maths around battery capacity instead, see how charge time scales with battery size across the kWh axis.

Level 2 amperage is a simple lever with a hard stop. Below the car's onboard ceiling, more amps mean a faster charge in direct proportion; above it, the surplus is wasted on a bigger circuit. Knowing both numbers, the amperage you can supply and the power your car will accept, turns the chart above into a precise answer for your own driveway.