Method of controlling discharge, battery pack, electrical storage system, electronic apparatus, electric vehicle and power system

1. A method of controlling discharge in a battery pack, comprising:

measuring an ambient temperature of a battery cell and a voltage of the battery cell;

performing a first discharge processing of discharging the battery cell when the ambient temperature of the battery cell is higher than a first reference temperature and the voltage of the battery cell is higher than a first reference voltage and the first discharge processing continues when the ambient temperature of the battery cell is higher than a second reference temperature and the voltage of the battery cell is higher than a second reference voltage;

performing a second discharge processing of discharging the battery cell when the ambient temperature of the battery cell is lower than the first reference temperature and the voltage of the battery cell is higher than a third reference voltage and the second discharge processing continues when the ambient temperature of the battery cell is lower than the first reference temperature and the voltage of the battery cell is higher than a fourth reference voltage.

2. The method of controlling discharge according to claim 1 ,

wherein the second reference temperature is lower than the first reference temperature.

3. The method of controlling discharge according to claim 1 ,

wherein the first discharge processing and the second discharge processing are performed by applying current to a discharge line,

wherein the discharge line includes

a positive line connected to a positive electrode of the battery cell,

a negative line connected to a negative electrode of the battery cell,

a first terminal connected to the positive line and disposed in a control section,

a second terminal disposed in the control section and outputting a control signal having a different voltage level in response to a voltage of the battery cell, and

a resistor connected between the second terminal and the negative line.

4. A battery pack comprising:

a battery cell; and

a control section to which information on an ambient temperature of the battery cell and information on a voltage of the battery cell are input,

wherein the control section performs a first discharge processing of discharging the battery cell when the ambient temperature of the battery cell is higher than a first reference temperature and the voltage of the battery cell is higher than a first reference voltage and the first discharge processing continues when the ambient temperature of the battery cell is higher than a second reference temperature and the voltage of the battery cell is higher than a second reference voltage;

the control section performs a second discharge processing of discharging the battery cell when the ambient temperature of the battery cell is lower than the first reference temperature and the voltage of the battery cell is higher than a third reference voltage and the second discharge processing continues when the ambient temperature of the battery cell is lower than the first reference temperature and the voltage of the battery cell is higher than a fourth reference voltage.

5. The battery pack according to claim 4 ,

wherein the second reference temperature is lower than the first reference temperature.

6. A battery pack comprising:

a battery cell;

a positive line connected to a positive electrode of the battery cell;

a negative line connected to a negative electrode of the battery cell; and

a control section to which information on an ambient temperature of the battery cell and information on a voltage of the battery cell are input and which has at least a first terminal connected to the positive line and a second terminal outputting a control signal having a different voltage level in response to a voltage of the battery cell; and

a resistor connected between the second terminal and the negative line,

wherein the control section performs a first discharge processing of discharging the battery cell when the ambient temperature of the battery cell is higher than a first reference temperature and the voltage of the battery cell is higher than a first reference voltage and the first discharge processing continues when the ambient temperature of the battery cell is higher than a second reference temperature and the voltage of the battery cell is higher than a second reference voltage, and wherein the control section performs a second discharge processing of discharging the battery cell when the ambient temperature of the battery cell is lower than the first reference temperature, and the voltage of the battery cell is higher than a third reference voltage and the second discharge processing continues when the ambient temperature of the battery cell is lower than the first reference temperature and the voltage of the battery cell is higher than a fourth reference voltage, and

the first discharge processing and the second discharge processing are configured to be performed by applying current to a discharge line including the positive line, the first terminal, the second terminal, the resistor and the negative line.

7. The battery pack according to claim 6 ,

wherein the resistor is included in a switching element.

8. The battery pack according to claim 7 ,

wherein the switching element is a digital transistor including a first resistor, a second resistor, and a transistor,

wherein, the first resistor is connected between the second terminal and a base terminal of the transistor and, the second resistor is connected in parallel between a base terminal and an emitter terminal of the transistor.

9. An electrical storage system, wherein the battery pack according to claim 4 is charged by a power generator performing power generation based on a renewable energy source.

10. An electrical storage system comprising the battery pack according to claim 4 , wherein the electrical storage system is configured to supply electric power to electronic apparatus connected to the battery pack.

11. An electronic apparatus receiving electric power from the battery pack according to claim 4 .

12. An electric vehicle comprising:

a conversion device that receives electric power from the battery pack according to claim 4 and converts the power into a driving force of the electric vehicle; and

a control device that performs information processing related to vehicle control based on information related to the battery pack.

13. A power system comprising a power information transmission and reception unit that transmits and receives signals to and from external apparatuses via a network,

wherein the power system is configured to perform charge and discharge control of the battery pack according to claim 4 based on information received by the power information transmission and reception unit.

14. A power system configured to receive electric power from the battery pack according to claim 4 or to supply electric power to the battery pack from a generator or a power network.

15. The battery pack according to claim 4 ,

wherein the first reference voltage is higher than the second reference voltage and the third reference voltage is higher than the fourth reference voltage.

16. The battery pack according to claim 15 ,

wherein the fourth reference voltage is higher than the first reference voltage.

17. The battery pack according to claim 6 ,

wherein the first reference voltage is higher than the second reference voltage and the third reference voltage is higher than the fourth reference voltage.

18. The battery pack according to claim 17 ,

wherein the fourth reference voltage is higher than the first reference voltage.