Why different charges on different days?

You might have noticed you don't always get the maximum charging speed stated by your car manufacturer or listed on the charging device. You might even get different charging speeds on different days. Why is this?

  • The charge level of your car: The state of charge (SoC) shows how charged a battery is in percentage form. Batteries charge faster when they're almost empty – when they have a low SoC.
  • Battery temperature: When a battery is too cold, it charges more slowly.
  • Other charging issues: Some of the energy destined for your battery may be directed to other elements during fast charging. These include air conditioning or interior heating, lighting, radio and other accessories. The thermal management system also uses some charging power to heat or cool the battery.
  • Battery wear: Although this takes time, batteries can wear out and lose their charging capacity over the course of their lives. When fast charging, it's recommended to stop charging at 80-85% SoC. This will keep your battery from overheating and give you more free time (the charging speed slows down when your battery is close to full).
  • Current and voltage limits of your electric car: Both your car and charger have voltage and current limits.

When you connect to a DC fast charger, both your EV and the charger provide the fastest possible speed – in the safest way – to keep your EV-battery healthy.