Device and method for ascertaining the temperature in an electrical battery

A device for ascertaining the temperature in an electrical battery comprising:

• at least one temperature sensor arranged outside a battery in the vicinity of the battery;
• a voltmeter for measuring battery terminal voltage;
• and
• a device for ascertaining battery terminal current and having an evaluation unit, which is connected to the at least one temperature sensor, the voltmeter, and the device for ascertaining the battery terminal current, and is designed for carrying out a method comprising the steps of:
• determining at least one temperature value at a temperature measuring point outside the battery in the vicinity of the battery;
• determining at least one electrical power value in dependence on a characteristic power variable associated with the operation of the battery;
• assigning the power values and the temperature values with a weighting factor;
• and
• determining the temperature in the electrical battery from an energy balance equation in dependence on the at least one weighted temperature value and the weighted electrical power values.