How long will it take to charge my EV cars battery?
- 3 min reading time
Charging time for an electric vehicle (EV) battery depends on several key factors. This guide walks you through the most important considerations that affect how long it takes to charge your EV using a portable or home EV charger.
Pro Tips Before You Start
- Check your vehicle's manufacturer specifications. Your car's handbook, user manual, or manufacturer's website will list the battery capacity (kWh) along with estimated charging times for both AC and DC chargers.
- Use your car's onboard display. Once you begin charging, your EV will show a real-time estimate of how long it will take to reach a full charge — accessible via the dashboard information screen or control panel.
Factors That Affect EV Charging Time
1. Battery Capacity (kWh) The size of your EV's battery is one of the biggest factors. A 60 kWh battery will take roughly twice as long to charge as a 30 kWh battery, all else being equal.
2. Battery Age and Condition As an EV battery ages, its ability to hold a full charge and accept power at peak rates gradually decreases. An older battery may charge more slowly than a newer one of the same capacity.
3. Your EV's Maximum AC Charging Rate (Onboard Charger) Every EV has a built-in onboard charger (OBC) that limits how much AC power it can accept. Many EVs are capped at around 7.4 kW for AC charging — meaning that connecting to a higher-rated charger won't speed things up if your OBC can't handle the extra power.
4. EV Charger Output Power (kW) The rated output of your EV charger directly affects charging speed. Note that real-world output is typically 5–10% lower than the charger's maximum rated power, due to grid supply conditions, circuit quality, and normal efficiency losses.
5. Input Power from Your Electrical Circuit The quality and capacity of the electricity supply feeding your charger determines the maximum power it can deliver. A weak or unstable circuit will reduce charging speed.
6. State of Charge (SoC) at the Start A nearly depleted battery will take longer to charge than one that's already partially charged. Charging speed can also slow as the battery approaches 100%, as most EVs taper charge rate to protect battery health.
A simple way to Calculate EV Charging Time
Working off a nominal voltage of 230V (Europe) you can estimate charging time with a simple formula:
Charging Time (hours) = Battery Capacity (kWh) ÷ Charger Output (kW)
Example — using a 3.68 kW charger (230V × 16A):
- 20 kWh battery: 20 ÷ 3.68 = ~5.4 hours
- 60 kWh battery: 60 ÷ 3.68 = ~16.3 hours
Example — using a 7.4 kW charger:
- 20 kWh battery: 20 ÷ 7.4 = ~2.7 hours
- 60 kWh battery: 60 ÷ 7.4 = ~8.1 hours
These are estimates for a fully depleted battery under ideal conditions. For accurate figures specific to your vehicle, always refer to your manufacturer's documentation.