LG_Fast charging_Factors2
This example shows that the charging speed decreases when the battery is around 70% full, and the charging power is further reduced at 80% and 90% SoC. The charging curve for each car is different and depends on the manufacturer's choices and configuration in their battery control system.
2. How cold or warm the batteries are (temperature)
The battery's optimal operating temperature is around 20-30°C. In winter, the lithium ions/electrons move slower in the electrolyte, and electrochemical processes are sensitive to temperature changes. At the same charging power (number of kW), the cell voltage can be higher at low temperatures than at more ideal battery temperatures. Thus, high charging power at low battery temperatures can potentially damage the battery cells. Therefore, the charging power is reduced to protect the battery, and the battery control system in electric vehicles will reduce the current from the charging point. Similarly, a battery can become too hot when charging, which can also damage the battery cells, thus limiting the charging power to protect the battery.
Many electric cars are therefore equipped with thermal management of the battery, allowing the battery to be cooled or heated depending on the surroundings. This reduces the effect of temperature, making it easier to maintain an optimal operating temperature during charging.