Charge speed is measured in kW and is determined by a number of different factors such as the charger’s capacity and the size of your vehicle’s battery.
At our stations, you can find 50kW chargers, 150kW chargers, and 350kW chargers. Provided that the charger has the right connector for your vehicle, you can use any charger (even one with a higher maximum charge speed than what your vehicle supports). It is important to note however that despite using a charger with a higher max charge speed, the charge speed will be limited to what your vehicle supports.
For example, you drive a car with a maximum charge speed of 50kW. You can use any of our chargers (i.e., a 350 kW charger), but you will not be able to charge faster than 50 kW.
So the size of your vehicle's battery and the charger's charge speed are obvious variables, but what are other factors that affect charge speed?
Influence of battery % on charge speed
Battery percentage plays a big role in the charging speed.
The graph below is an example of a charge curve. It demonstrates the charge speed (vertical axis, expressed in kW) depending on the battery percentage (horizontal axis).
In this example, the charge speed starts to drop when the car reaches 70% charge. It can also be seen that the drop is steeper once the battery reaches 80% + charge and therefore, the charge speed is significantly affected. As a result, it is less effective to fast charge once your vehicle hits 80%-90% charge.
It is important to note that the charge curve is different for each vehicle.
Influence of temperature on charge speed
The temperature of the battery is another factor that can significantly influence the charge speed. A battery performs optimally when the temperature is between 20° C and 30° C° (and in some cases 40° C for certain cars).
In winter the battery can get very cold (especially when parked outside). This can cause a slower charging speed. Warmer weather can also cause the battery to become too hot and result in a slower charging speed.
The level of influence weather has on a vehicle depends on the vehicle model. Some models are equipped with thermal management for the battery meaning it can be cooled or heated as a mode of intervention.
Fun fact- fast charging is an effective way to heat up your battery.