Method and device for managing the thermal behavior of a battery

1. A method for managing thermal behavior of a battery, comprising:

determining a time constant of the battery, the time constant corresponding to a time interval existing between a moment at which thermal energy is given off by the battery and a moment at which a corresponding rate of heat flow is measured at a surface of the battery,

measuring electrical power passing through the battery;

employing a thermal model of the battery, wherein the model is configured to estimate, at each point in time, a thermal power generated by the battery depending on the measured electrical power passing through the battery, the thermal model comprising a charging law and a discharging law, each law being based on a state of charge of the battery and on a temperature of the battery and incorporating the time constant (τ) of the battery, and

controlling the thermal power generated by the battery comprising determining the thermal power using the model and controlling the electrical power passing through the battery based upon the determined thermal power.

2. The method according to claim 1 , comprising:

estimating the thermal power generated at each point in time by the battery depending on the electrical power delivered at each point in time by the battery during charging thereof or generated at each point in time by the battery during discharging thereof, the thermal power being determined using the thermal model,

comparing the thermal power estimated at each point in time, or a variation in the estimated thermal power over time, during charging or during discharging, with a limiting value, and

controlling the electrical power delivered to the battery during charging or generated by the battery during discharging in order to keep the estimated thermal power below the limiting value.

3. The method according to claim 1 , comprising:

determining at each point in time a limiting value of the electrical power that is acceptable to the battery on a basis of a limiting value of the thermal power that is acceptable, the limiting value of the thermal power being stored in memory beforehand and used in the thermal model, and

controlling the electrical power passing through the battery during charging or during discharging in order to keep the electrical power passing through the battery below the limiting value.

4. The method according to claim 1 , comprising estimating the thermal power, at each point in time, also taking into account a state of health of the battery.

5. The method according to claim 1 , comprising establishing the thermal model of the battery.

6. The method according to claim 1 , comprising verifying the thermal model of the battery, by comparing the thermal power measured at a plurality of times during charging or during discharging with the thermal power estimated at said times using the thermal model of the battery, not corrected for the time constant of the battery.

7. A device for managing thermal behavior of a battery, comprising:

a module configured to determine a time constant of the battery, the time constant corresponding to a time interval existing between a moment at which thermal energy is given off by the battery and a moment at which a corresponding rate of heat flow is measured at a surface of the battery, the module being configured to measure electrical power passing through the battery;

a module configured to execute a thermal model of the battery, wherein the model is configured to estimate, at each point in time, a thermal power generated by the battery depending on the measured electrical power passing through the battery, the thermal model comprising a charging law and a discharging law, each law being based on a state of charge of the battery and on a temperature of the battery and incorporating the time constant of the battery, and

a module configured to control the thermal power generated by the battery comprising determining the thermal power using the model and controlling the electrical power passing through the battery based upon the determined thermal power.

8. The device according to claim 7 , comprising:

a module configured to estimate the thermal power generated at each point in time by the battery depending on the electrical power delivered at each point in time by the battery during charging thereof or generated at each point in time by the battery during discharging thereof, the thermal power being determined using the thermal model,

a module configured to compare the thermal power estimated at each point in time, or a variation in the estimated thermal power over time, during charging or during discharging, with a limiting value, and

a module configured to control electrical power delivered to the battery during charging or generated by the battery during discharging in order to keep the estimated thermal power below the limiting value.

9. The device according to claim 7 , comprising:

a module configured to determine at each point in time a limiting value of the electrical power that is acceptable to the battery on a basis of a limiting value of the thermal power that is acceptable, the limiting value of the thermal power being stored in memory beforehand and used in the thermal model, and

a module configured to control the electrical power passing through the battery during charging or during discharging, the module being configured to keep the electrical power passing through the battery below the limiting value.

10. The device according to claim 8 , wherein the module configured to estimate the thermal power is configured to estimate, at each point in time, taking into account a state of health of the battery.

11. The device according to claim 7 , comprising a module configured to establish the thermal model of the battery.

12. The device according to claim 7 , comprising a module configured to verify the thermal model of the battery and to compare thermal power measured at a plurality of times during charging or during discharging with the thermal power estimated at the times using the thermal model of the battery, not corrected for the time constant of the battery.

13. The method according to claim 1 , wherein the controlling comprises:

determining limiting values for the electrical power passing through the battery during charging and discharging, respectively,

determining a range between corresponding ones of the limiting values during charging and discharging,

updating at a plurality of times, the limiting values, to produce a corresponding plurality of ranges, and

maintaining the electrical power to be with the ranges.