Charging Speed Chart

Charging speed at home is one multiplication: the power actually flowing into the car, in kilowatts, multiplied by the car's efficiency in miles per kilowatt-hour. That gives miles of range added per hour of charging, which is the only unit that means anything to somebody deciding what to install. The complication, and it is the single most expensive misunderstanding in home charging, is that the power flowing into the car is not set by the unit on the wall. It is set by whichever of the two is smaller.

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How fast will each car charge at each charger output?

Read across a row and watch where the numbers stop climbing. That point is the onboard charger saturating, and every dollar of circuit capacity beyond it buys nothing whatsoever. The last column is what an overnight window of roughly ten hours returns at the largest output the car can use.

Three patterns are worth pulling out of that table. The first is the Nissan Leaf row, which is flat from the 7.7 kW column onwards. A Leaf owner who pays for a 60 amp circuit and a 48 amp charger gets exactly the same charging speed as one who pays for a 40 amp circuit and a 32 amp charger, and the difference in install cost is several hundred dollars. The early Toyota bZ4X behaves the same way. If your car is in that group, spend the saving on cable length instead.

The second is that the 19.2 kW column is populated for exactly one vehicle. The Ford F-150 Lightning with the appropriate equipment can accept 19.2 kW, and doing so requires an 80 amp charger on a 100 amp branch circuit, which consumes half of a typical 200 amp service on its own. Almost every Lightning owner is better served by a 48 amp circuit, and the reasoning is set out on the F-150 Lightning page.

The third is that efficiency matters as much as power. The Tesla Model 3 and the Rivian R1T both have an 11.5 kW onboard charger, and the Model 3 gains nearly twice the range per hour, because it travels almost twice as far on the same kilowatt-hour. Miles per hour is a product of two numbers, and only one of them is on the charger's box.

What if my car is not in the table?

Find your efficiency in miles per kWh, which is on the window sticker or in the trip computer, then read down the column. Charger outputs on the left are the standard ladder, and the breaker each one requires is shown so you can see the install cost implied by the row.

Cross-check the row you land on against your car's onboard limit before you believe it. If the car caps at 7.2 kW, the 9.6 and 11.5 kW rows do not apply to you at all, no matter what the wall unit is rated. The onboard limits for current models are on the battery capacity chart, and the full argument about matching amperage to the car is in how many amps an EV charger needs.

Why is the car the limit and not the charger?

The unit on your wall is not, strictly speaking, a charger. It is electric vehicle supply equipment, and its job is to deliver alternating current safely, negotiate with the vehicle over how much current is available, and disconnect if anything is wrong. The actual charger, the device that converts AC to the DC the battery needs, lives inside the car. That converter is a physical component with a rating, and it is sized by the manufacturer against cost, weight, cooling and how the car is expected to be used.

Most manufacturers landed on 11 to 11.5 kW, because that saturates a 48 amp circuit and covers overnight charging for even a large pack. A few economised: 6.6 kW appears on the Nissan Leaf and on early Toyota bZ4X model years, and 7.2 kW appears on various older vehicles. One, the F-150 Lightning, went the other way to 19.2 kW because a 131 kWh pack takes a long time to fill at 11.5 kW.

None of this applies to public DC fast charging, which bypasses the onboard charger entirely and feeds DC straight to the pack. That is why a car limited to 6.6 kW at home can still take 100 kW on the road. It is also why the two numbers get confused so often, and why a spec sheet that advertises a large fast-charging figure tells you nothing at all about what your garage circuit should be.

Does an overnight window ever actually run out?

Rarely, and this is the calculation that should settle most purchase decisions. Assume ten hours plugged in, which is a conservative overnight window for a car home at nine and gone at seven.

The average American drives around 37 miles a day. Even the 16 amp row, the cheapest genuine Level 2 available, covers that three times over for a sedan. The 24 amp dryer-circuit row covers it five times over. The honest conclusion is that for most households the overnight window is not the binding constraint, and the reason to buy a larger circuit is not daily commuting but the occasional day where the car arrives home nearly empty and has to leave full.

That is the case where a large pack changes the answer. A Rivian R1T or a Cybertruck arriving home at ten percent needs well over 100 kWh, which is ten hours at 11.5 kW and fifteen at 7.7 kW. If your driving includes those days with any regularity, the 48 amp circuit earns its cost. If it does not, it is insurance. The charge time chart works that out properly for every pack size.

What else changes the number on the day?

Voltage

Every figure on this page assumes a nominal 240 volts. Some multi-family and converted commercial buildings supply 208 volts, which drops the power by roughly 13 percent for the same amperage: a 40 amp charger delivers 8.3 kW rather than 9.6. Sagging voltage on a long undersized run does the same thing quietly, which is one of the practical reasons to care about voltage drop.

Temperature

In genuine cold the pack must be warmed before it will accept full current, so the first part of a session can be slow while the car heats the battery. Preconditioning the cabin on a timer draws from the same supply. Efficiency in miles per kWh also falls independently, sometimes by 20 to 30 percent. The combined effect is that a winter night can return a quarter less range than this chart suggests.

State of charge and battery management

AC charging is far more linear than DC, but the last few percent still taper as the pack balances, and many owners set a daily limit of 80 or 90 percent anyway. If you charge to a limit rather than to full, the practical session is shorter than the arithmetic and the chart is conservative.

The charger's own setting

A surprising number of slow-charging complaints resolve to a unit that was dialled down at commissioning and never turned back up. Most smart chargers let an installer set a maximum output, and a cautious electrician facing an unclear panel situation may have set 32 amps on a 48 amp capable unit. Check the app before you blame the car. That and the other common causes are covered in EV charger troubleshooting.

What to buy once you have read the chart

If your car's onboard limit is 11 kW or above and the panel has room, the 48 amp column is the one to wire for, and the Emporia 48 amp hardwired unit covers it at the low end of the price range while the ChargePoint HomeFlex and the Wallbox Pulsar Plus cover it at the premium end. If the limit is 7.2 kW or below, buy the 32 to 40 amp column and stop: the Grizzl-E Classic or the AIMILER 32 amp unit with a 25 foot cable deliver every kilowatt your car can take.

Either way, prioritise cable length over amperage once the car's ceiling is met. A 25 foot cable solves parking direction, port location, a second vehicle and a change of habit. Two extra kilowatts your car cannot accept solves nothing. The shortlist at each budget is in the best Level 2 home chargers.

Common questions

How many miles per hour does a Level 2 charger add?

A 40 amp charger delivering 9.6 kW adds roughly 30 to 38 miles of range per hour for a typical electric crossover, and a 48 amp charger delivering 11.5 kW adds roughly 36 to 45. A large electric truck at around 2.2 miles per kWh gets closer to 21 and 25 miles per hour respectively. The figure is simply charger power multiplied by the vehicle efficiency in miles per kWh.

Why does my car charge slower than the charger is rated?

Almost always because the car, not the charger, is the limit. The vehicle contains its own AC to DC converter called the onboard charger, and it has a hard ceiling. A Nissan Leaf caps at 6.6 kW, so a 48 amp wall unit delivers 6.6 kW to it, exactly what a 32 amp unit would. The other common causes are a charger dialled down at commissioning and a 208 volt supply instead of 240.

Is a 48 amp charger worth it over a 40 amp one?

It depends entirely on the car. On a vehicle with an 11.5 kW onboard charger the step from 9.6 to 11.5 kW is real, worth roughly six miles of range per hour. On a vehicle capped at 6.6 or 7.2 kW it is worth nothing at all, because neither unit can push more than the car accepts. The 48 amp unit also requires a 60 amp circuit rather than a 50 amp one.

How much range does an overnight charge actually add?

Take the charger power, multiply by the vehicle efficiency, and multiply by the hours plugged in. A 9.6 kW charger over ten hours delivers around 96 kWh of billed energy, which is 300 miles for an efficient sedan and around 210 for a large truck. In practice the pack fills before that on most cars, which is why the overnight window rarely constrains a normal commute.

Does cold weather change these numbers?

Significantly. In genuine cold the pack has to be warmed before it will accept full current, cabin preconditioning draws from the same supply, and efficiency in miles per kWh falls independently. It is realistic to lose a quarter of the figures shown on a cold night. Size the circuit so the overnight window has slack rather than exactly enough.

Does a bigger battery charge more slowly on AC?

It takes longer to fill, but not more slowly. AC charging is essentially linear because the onboard charger runs at a fixed power for almost the whole session, unlike DC fast charging where the taper dominates. A 135 kWh pack at 11.5 kW simply needs more hours than a 60 kWh pack at the same power. That is precisely why the largest packs justify the 48 amp circuit.

Getting your own panel and load numbers ready for an electrician? The EV Home Charging Install Planner is the paid version of these pages: 8 printable worksheets you fill in with your own numbers, plus the full PDF, $29.