Patent-family-84520083

The invention refers to a transport refrigeration system, in particular for a storage unit (10), comprising a storage volume and a refrigerant circuit for cooling said storage volume, said refrigerant circuit, wherein during a travelling period said refrigerant circuit is powered by said energy storage unit (battery). In order to operate such a transport refrigeration system at minimum costs for the electric energy, in a charging location said refrigerant circuit powered by a charger (200) connected to a local electrical grid. A controller (120) determines the charge level of said energy storage unit and calculates the required recharge energy and further calculates the required precooling energy and the required keep setpoint energy and said controller uses a given price correlation for the electric energy consumed within the remaining rest period for a price optimized timing of a recharge period and timing a precooling period.