Abstract: Ascertaining a charge state of a battery system that includes at least one battery cell and one additional energy store that is connected in series with the at least one battery cell and can be switched in and out. One method includes switching in the additional energy store; measuring a voltage of the additional energy store at predefined time intervals; ascertaining a capacity change of the additional energy store with reference to the measured voltage and to a characteristic voltage curve of the additional energy store; ascertaining a charge throughput of the additional energy store with reference to the ascertained capacity change of the additional energy store; and ascertaining the charge state of the battery system with reference to the ascertained charge throughput.

Abstract: The invention relates to a method for operating a fuel cell system (10) using a first operating mode, in which, when all of the fuel cell stacks (22, 26) are inactive, one fuel cell stack (22) is pre-heated using a coolant that is pre-heated by means of an electric heater (42) while bypassing all cooler circuits (58) of the active coolant circuits (14) via bypass lines (64) and the one pre-heated fuel cell stack (22) is activated in order to pre-heat an additional fuel cell stack (26) of the fuel cell system. Other operating modes for operating a fuel cell system are disclosed in additional embodiments.

Abstract: Ascertaining a charge state of a battery system that includes at least one battery cell and one additional energy store that is connected in series with the at least one battery cell and can be switched in and out. One method includes switching in the additional energy store; measuring a voltage of the additional energy store at predefined time intervals; ascertaining a capacity change of the additional energy store with reference to the measured voltage and to a characteristic voltage curve of the additional energy store; ascertaining a charge throughput of the additional energy store with reference to the ascertained capacity change of the additional energy store; and ascertaining the charge state of the battery system with reference to the ascertained charge throughput.

Abstract: Electrical energy storage system comprising a plurality of electrochemical energy storage units, which are electrically connectable by means of first switches to first terminal poles of the electrical energy storage system for providing a first electrical voltage; at least one second terminal pole for providing a second electrical voltage; at least one sensor for detecting a voltage variable representing an electrical voltage of one or more electrochemical energy storage units, and/or a temperature variable representing a temperature of one or more electrochemical energy storage units; at least one second switch, which is electrically connected to at least one of the electrochemical energy storage units, wherein, by means of the second switch, a pole of the at least one electrochemical energy storage unit is electrically connectable to the second terminal pole for providing the second electrical voltage, which is substantially equal to or less than the first electrical voltage, depending on the detected volta

Abstract: The invention relates to a method for operating a fuel cell system (10) using a first operating mode, in which, when all of the fuel cell stacks (22, 26) are inactive, one fuel cell stack (22) is pre-heated using a coolant that is pre-heated by means of an electric heater (42) while bypassing all cooler circuits (58) of the active coolant circuits (14) via bypass lines (64) and the one pre-heated fuel cell stack (22) is activated in order to pre-heat an additional fuel cell stack (26) of the fuel cell system. Other operating modes for operating a fuel cell system are disclosed in additional embodiments.

Abstract: An electrode arrangement of a battery cell (10) comprising a positive electrode layer (2) and a negative electrode layer (3), which are separated from one another in an electrically insulating manner by a separator layer (4), wherein the positive electrode layer (2) forms a plurality of first contacting sections (21) formed in each case for an electrical contacting of the positive electrode layer (2) by a first current conductor (81), and the negative electrode layer (3) forms a plurality of second contacting sections (31) formed in each case for an electrical contacting of the negative electrode layer (3) by a second current conductor (82).

Abstract: An electrode arrangement of a battery cell (10) comprising a positive electrode layer (2) and a negative electrode layer (3), which are separated from one another in an electrically insulating manner by a separator layer (4), wherein the positive electrode layer (2) forms a plurality of first contacting sections (21) formed in each case for an electrical contacting of the positive electrode layer (2) by a first current conductor (81), and the negative electrode layer (3) forms a plurality of second contacting sections (31) formed in each case for an electrical contacting of the negative electrode layer (3) by a second current conductor (82).

Abstract: A contact element for mechanically, thermally and electrically contacting at least one energy store at least partially delimits at least one accommodating space for accommodating the at least one energy store. The contact element is designed for a force-fit, form-locked and/or integral joint with at least one subarea of the energy store, the contact element being at least partially electrically conductive, and the contact element being at least partially thermally conductive.

Abstract: A battery module having a plurality of battery cells positioned adjacent to one another and electrically connected to one another, between which the thermal resistance between adjacent battery cells may be increased in the case of a malfunction of the battery module and/or of individual battery cells, in order to prevent overheating of adjacent cells. In addition, a method for thermally decoupling battery cells in the case of a malfunction is described.

Abstract: A contact element for mechanically, thermally and electrically contacting at least one energy store at least partially delimits at least one accommodating space for accommodating the at least one energy store. The contact element is designed for a force-fit, form-locked and/or integral joint with at least one subarea of the energy store, the contact element being at least partially electrically conductive, and the contact element being at least partially thermally conductive.

Abstract: An electrochemical energy store, including, for example, a battery or a rechargeable battery, having a first electrochemical unit having a first anode, a first cathode, and a first power terminal, which is electrically conductively connected to the first cathode, a second electrochemical unit having a second anode, a second cathode, and a second power terminal, which is electrically conductively connected to the second anode, and having a housing having a first housed area, in which the first electrochemical unit is situated, a second housed area, in which the second electrochemical unit is situated, and a partition wall, which separates the first housed area from the second housed area. The anode of the first electrochemical unit is electrically conductively connected to the cathode of the second electrochemical unit.

Abstract: A battery module having a plurality of battery cells positioned adjacent to one another and electrically connected to one another, between which the thermal resistance between adjacent battery cells may be increased in the case of a malfunction of the battery module and/or of individual battery cells, in order to prevent overheating of adjacent cells. In addition, a method for thermally decoupling battery cells in the case of a malfunction is described.

Abstract: The state of charge of at least one battery unit of a rechargeable battery is initially estimated, and at least one variable of the battery unit which describes the state of health of this battery unit at a selected operating point with the aid of a model is estimated. The variable describing the state of health is an instantaneous charge capacity of the battery unit, which is estimated from the load current of the battery unit at the operating point and the reciprocal value of the derivation over time of the previously estimated state of charge of the battery unit.