There are a number of factors which affect an EV’s charging speed with DC charging. However, because the AC/DC converter is located in the charging station itself, charging an electric vehicle with DC charging can be significantly faster than with AC charging.
Different factors which affect a vehicle’s charging speed with DC charging include the battery’s current charge, the weather conditions (batteries charge slower in the cold), the battery’s charging capabilities, and, of course, the power output.
Battery’s current charge: Due to measures to increase battery life and ensure safe charging, charging slows down significantly for the final 20 percent. As DC fast charging takes an EV's battery to 80 percent capacity in a comparatively short amount of time versus AC charging and then slows down for the remaining 20 percent, the time it takes for your battery to reach 100 percent full may be the same for the initial 80 percent charge.
Weather conditions: Depending on where you are charging your EV, the temperature may effect the charging speed. Cold temperatures can negatively impact charging speeds due to the fact that lithium-ion batteries—those used to power EVs—are very sensitive in low temperatures.
Power output: Obviously, the power output of the charger will have an effect on charging times. For example, 15 minutes of charging time can give you between 130 km and 480 km additional range at 100 kW and 350 kW output respectively. At 50 kW, one hour of charging a passenger vehicle will add an additional 278 km of range.
Additionally, we always say that the car is the “master” when it comes to dictating charging times. Some vehicles can accept more power than others. For example, while a Tesla Model 3 can accept 250 kW, a Nissan Leaf can only accept about 50 kW.
See this blog post for more information about how to make the most out of DC fast and ultra-fast charging.