Is your EV not charging as quickly as you expected? While higher charging power typically means shorter charging times, several factors can influence the speed. To achieve the fastest charging, all components—from the power grid to your car—must work together seamlessly.
In this article, we’ll explore these factors to help you understand how they influence EV charging, regardless of the charger model.
Main power grid
The voltage on the power supply to your home determines how fast you can charge the electric (EV) vehicle. There are two main types of grids: 400V (TN) and 230V (IT), and these can be set up with either a 1-phase or a 3-phase connection.
Most homes in Norway do for example use the 230V (IT) grid, which allows for a maximum charging effect of 11kW on a 3-phase installation. The type of grid and setup at your home will influence the charging speed available to you.
Info
Zaptec charging stations adapt to various electrical setups, supporting IT and TN installations with up to 32A on 1-phase and 3-phase connections.
The circuit breaker
The circuit breaker in your home controls how much electricity can flow to the charging station. If the circuit breaker has a lower capacity than what your charging station supports (e.g., 32A for 1-phase or 3-phase), it will limit the maximum charging speed. The circuit breaker is designed to match your home's electrical setup and ensures safe operation.
Charging cable
The charging cable is an important part of the setup and can also limit the charging speed. Cables come in different capacities, ranging from 16A 1-phase to 32A 3-phase. Using a cable with a lower capacity than your charger or car supports will slow down charging.
On-Board Charger (OBC)
Every EV has an On-Board Charger (OBC), which controls how fast the battery can be charged. The size and efficiency of the OBC determine the maximum charging speed. Most OBCs range between 3.3kW and 22kW. Even if your charging station and cable can deliver more power, the OBC will limit the speed if it’s smaller.
Temperature and charging speed
Temperature affects how efficiently your EV charges. Let’s break it down:
High temperatures: When charging, the flow of electricity generates heat. For example, the Zaptec Go charging station uses six sensors to monitor key points, such as the energy meter, charging connector, and internal components. If it detects excessive heat—caused by direct sunlight, poor ventilation, or high outdoor temperatures—it can reduce power temporarily to cool down. This ensures safe and reliable operation.
Low temperatures: Cold weather can slow down charging because EV batteries work best within a certain temperature range, typically between 20°C and 30°C. If the battery is too cold, its management system (BMS) will limit charging power to protect the battery. This can lead to longer charging times, especially in winter. Some EVs and chargers include features to preheat the battery, which helps improve charging speed in cold conditions.
Factors influencing temperature include exposure to sunlight, limited airflow around the charger, installation on insulating surfaces, and cables with small cross-sections. Keeping the charger in a shaded and ventilated area can help maintain optimal charging performance.
Zaptec is continually improving its technology to balance safety and performance, ensuring fast and reliable charging even in challenging weather conditions.
What is the difference between kW and kWh?
- kWh (Kilowatt-hour): Think of it like fuel. The kWh is the amount of energy going into your battery, like filling a tank with liters of fuel. More kWh means a fuller battery, letting you drive farther. You pay for electricity per kWh.
- kW (Kilowatt): Think of it like speed. kW is how fast energy fille your battery, like the speed of a pump at the gas station, and more kW means faster charging.
So kWh = how much energy, kW = how fast it chargers!