A thermally controllable battery pack, wherein the thermally controllable battery pack comprises: - at least one battery module, which each comprises a plurality of battery cells, - each battery module is surrounded by a sheet metal housing on at least three sides of the battery module, - a thermal fin between some of the adjacent battery cells, so that each battery cell has contact to at least one thermal fin, which thermal fins extend and fold on top of a side edge of the battery cell with 90 degrees angle, so that bent parts of the thermal fins form a substantially planar vertical outer surface with large thermal conductivity for the battery modules, where the thermal fins are made of sheet metal, characterized in that the battery pack further comprises - thermal fins extending and foldable along a bottom edge of the battery cell with 90 degrees angle, where the bent parts of the thermal fins form a substantially horizontal surface on the bottom surface of the battery module, - a foil heater along the bottom surface of the battery module, supplied by the battery pack itself or by an external power source, - a thermal pad between the sheet metal housing and the bent parts of the thermal fins on vertical end surfaces of the battery module, which thermal pad is made of an electrically insulating material and which is thermally conductive, - a controller and at least one temperature sensor, configured to sense the temperature within the battery pack, and to control the temperature of the battery pack by activating and deactivating the foil heaters as desired, - the two vertical surfaces of the battery modules comprising the thermal pads are completed with heat exchangers, - the top surface of the battery modules are completed with coolant pipes, feeding air or liquid of desired temperature to the heat exchangers, and - the controller is configured to control also the activity of the cooling system for controlling the temperature of the battery pack in case of excessive heat emerges within the battery pack. - at least one battery module, which each comprises a plurality of battery cells, - each battery module is surrounded by a sheet metal housing on at least three sides of the battery module, - a thermal fin between some of the adjacent battery cells, so that each battery cell has contact to at least one thermal fin, which thermal fins extend and fold on top of a side edge of the battery cell with 90 degrees angle, so that bent parts of the thermal fins form a substantially planar vertical outer surface with large thermal conductivity for the battery modules, where the thermal fins are made of sheet metal, characterized in that the battery pack further comprises - thermal fins extending and foldable along a bottom edge of the battery cell with 90 degrees angle, where the bent parts of the thermal fins form a substantially horizontal surface on the bottom surface of the battery module, - a foil heater along the bottom surface of the battery module, supplied by the battery pack itself or by an external power source, - a thermal pad between the sheet metal housing and the bent parts of the thermal fins on vertical end surfaces of the battery module, which thermal pad is made of an electrically insulating material and which is thermally conductive, - a controller and at least one temperature sensor, configured to sense the temperature within the battery pack, and to control the temperature of the battery pack by activating and deactivating the foil heaters as desired, - the two vertical surfaces of the battery modules comprising the thermal pads are completed with heat exchangers, - the top surface of the battery modules are completed with coolant pipes, feeding air or liquid of desired temperature to the heat exchangers, and - the controller is configured to control also the activity of the cooling system for controlling the temperature of the battery pack in case of excessive heat emerges within the battery pack.