Minimum charge when arriving at first charging station in kWh. This overrides BatterySpecifications.minChargeAtChargingStationInKilowattHours for the first charging station. If not specified, BatterySpecifications.minChargeAtChargingStationInKilowattHours will be used for all charging stations, including the first one. Defaults to null. When initialized, it must be non-negative and less than the value of BatterySpecifications.targetChargeInKilowattHours, otherwise the BatterySpecifications instance is considered invalid. This is usually used when the current charge is too low to reach a charging station within minChargeAtChargingStation limits.