EV charging speeds come down to a few simple numbers: kW, kWh, volts and amps. Once you understand how they relate, you can compare chargers, cables and power sources easily.

1. kW = Charging speed (how fast your EV charges)

kW (kilowatt) is the most important number. It tells you how much power a charger can deliver.

• 7.4 kW = common single-phase home charging
• 11 kW = Europe’s standard three-phase AC speed
• 22 kW = high-end AC chargers (car must support it)

A higher kW = faster charging.

2. kWh = Battery size (how much energy your EV stores)

kWh (kilowatt-hours) measures your battery’s total capacity. Example: A 70 kWh battery charged at 11 kW takes roughly 6–7 hours from low to full.

3. Volts × Amps = kW (the formula behind all charging speeds)

All charging speeds follow one simple formula:

Volts × Amps = Watts (kW)

Example with a 3-phase 11 kW home charger:

• 400 V
• 16 A
• = 11 kW

4. AC vs DC speeds: why they differ

AC charging (home & public stations) is limited by your EV’s onboard charger. DC fast charging bypasses it and delivers far more power — 50 kW, 150 kW, even 350 kW.

5. Why your car rarely charges at the “maximum” speed

• Battery temperature limits speed
• Low or high state of charge reduces power
• Shared chargers split output between cars
• Your EV’s onboard charger may bottleneck AC speeds

6. Quick reference chart

• 3.7 kW → ~20–25 km per hour
• 7.4 kW → ~35–40 km per hour
• 11 kW → ~50–60 km per hour
• 22 kW → ~100–120 km per hour (car must support)

External resource – EU technical standard

For full technical details on European charging connectors and power levels, see: IEC 62196 standard.