Method and device for determining an operating temperature, operating method for a battery cell, control unit for a battery cell, and working device

A device configured to determine an operating temperature of a battery cell, the device comprising:

• an impedance measuring apparatus configured to measure an electrical impedance of the battery cell;
• a temperature sensor configured to measure a measured temperature exterior and adjacent to the battery cell;
• and
• a control unit configured to:
• determine an external temperature of the battery cell from the measured temperature,
• determine an internal temperature of the battery cell by detecting the electrical impedance of the battery cell, and
• determine an operating temperature of the battery cell from at least one of:
• the external temperature and the internal temperature,
• wherein, in a first operating state of the battery cell, the internal temperature of the battery cell is determined:
• at a first frequency, if a temperature profile of the battery cell is in a predefined first safe range, and
• at a second frequency greater than the first frequency, if the temperature profile of the battery cell is outside the predefined first safe range, and
• wherein the temperature profile reflects at least one of:
• the external temperature, the internal temperature and the operating temperature, of the battery cell.

A vehicle comprising:

• an electrically drivable assembly;
• a battery cell configured to supply the assembly with electrical energy in a controllable fashion;
• and
• a control device configured to control the operation of the assembly and/or of the battery cell, the control device being configured to:
• detect a value of a measured variable for determining an external temperature of the battery cell,
• determine an internal temperature of the battery cell by detecting an electrical impedance of the battery cell, and
• determine a value of an operating temperature of the battery cell from the external temperature and/or from the internal temperature,
• wherein at least in a first operating state of the battery cell the internal temperature of the battery cell
• is determined less frequently if the value of the determined external temperature, the internal temperature and/or the operating temperature of the battery cell is in a predefined first safe range, and
• is determined more frequently if the value of the determined external temperature, the internal temperature and/or the operating temperature of the battery cell is outside the predefined first safe range.