Electric vehicles
Why your EV is charging slowly
A charge is only as fast as the slowest part: the charger, the cable, the car's onboard charger and the battery's temperature and charge level all set a limit.
Updated 3 October 2026 · energy.org.uk editorial team
Common causes
- The car's AC limit. On home and most public AC chargers, the car's onboard charger sets the maximum. A car limited to 7 kW won't charge faster on a 22 kW post.
- The charger. A three-pin plug delivers about 2.3 kW; most home wallboxes about 7 kW.
- Three-phase power. 11 kW and 22 kW AC charging needs a three-phase supply and a car that can use it. Most homes have single-phase power.
- A cold battery. In cold weather, cars limit charging power to protect the battery, especially on rapid chargers. Preconditioning before a rapid charge helps, if your car has it.
- A nearly full battery. Rapid charging slows down a lot above about 80%.
- Shared power. Some rapid sites share power between connectors, and some home chargers reduce power to protect the house supply.
- Settings. The car or charger app may have a current limit or schedule set.
Check
What to check first
- Your car's maximum AC and DC charging power, in the electric car comparison.
- The charger's power rating, and whether it is shared.
- Charge limits and schedules in the car and charger apps.
Do
Practical next steps
- Work out the expected time for your car and charger in the EV charging calculator.
- If it's much slower than expected at home, check settings first, then ask your installer.
- On rapid chargers, charge from a lower level to around 80% and move on.
- Choosing a home charger? See the home EV charger chooser.
Take care
Important limitations
- The calculator uses typical charging curves; real charging varies with temperature and battery condition.
- Faults with a home charger should be checked by the installer or manufacturer, not opened yourself.