Methods and apparatus for a battery system

1. An apparatus capable of connecting to a battery, comprising:

a protection control circuit connected to the battery and configured to:

detect an over-charge event and generate a first control signal in response to the detected over-charge event; and

detect an over-discharge event and generate a second control signal in response to the detected over-discharge event;

a charge control device responsive to the first control signal;

a discharge control device responsive to the second control signal;

a fuel gauge circuit connected to the battery and in communication with the protection control circuit and configured to:

confirm the over-charge event in response to the first control signal;

count and record a total number of confirmed over-charge events;

confirm the over-discharge event in response to the second control signal; and

count and record a total number of confirmed over-discharge events; and

a recovery control device configured to discharge the battery in response to the confirmed over-charge event.

2. The apparatus according to claim 1 , wherein:

the over-charge event comprises over-current charging and over-voltage charging; and

the over-discharge event comprises over-current discharging and under-voltage discharging.

3. The apparatus according to claim 1 , wherein: the fuel gauge circuit comprises:

a voltage sensor to detect a voltage of the battery;

a first comparator to compare the voltage of the battery with a first predetermined threshold voltage, wherein the first comparator confirms the over-charge event and generates a third control signal; and

a second comparator to compare the voltage of the battery with a second predetermined threshold voltage, wherein the second comparator confirms the over-discharge event and generates a fourth control signal.

4. The apparatus according to claim 3 , wherein the fuel gauge circuit further comprises:

a first output control circuit configured to generate the third control signal in response to the first comparator output and the first control signal; and

a second output control circuit configured to generate the fourth control signal in response to the second comparator output and the second control signal.

5. The apparatus according to claim 1 , wherein the fuel gauge circuit comprises:

a first counter configured to count the number of over-charge events and output a first count value corresponding to the total number of confirmed over-charge events; and

a second counter configured to count the number of over-discharge events and output the second count value corresponding to the total number of confirmed over-discharge events.

6. The apparatus according to claim 1 , wherein the fuel gauge circuit is further configured to:

generate a third control signal in response to the confirmed over-charge event, wherein the recovery control device is responsive to the third control signal; and

generate a fourth control signal in response to the confirmed over-discharge event, wherein the fourth control signal starts a charging operation.

7. The apparatus according to claim 1 , wherein the battery, the protection control circuit, recovery control device, and the fuel gauge circuit are arranged in a single physical package, and wherein the physical package comprises:

a first terminal having a supply voltage level and connected to the battery, the fuel gauge circuit, and the recovery control device;

a second terminal configured for data communication and connected to the fuel gauge circuit;

a third terminal configured to transmit a fourth control signal and connected to the fuel gauge circuit; and

a fourth terminal having a reference voltage level and connected to the charge control device.

8. The apparatus according to claim 1 , wherein the recovery control device comprises a field-effect transistor comprising:

a gate terminal connected to the fuel gauge circuit and responsive to a third control signal;

a source terminal connected to a first terminal of the battery; and

a drain terminal connected to a second terminal of the battery.

9. A method for managing over-charging and over-discharging events in a battery, comprising:

detecting an over-charge event and generating a first control signal in response to the detected over-charge event;

detecting an over-discharge event and generating a second control signal in response to the detected over-discharge event;

confirming the over-charge event in response to the first control signal;

performing a self-discharging operation in response to the confirmed over-charge event;

confirming the over-discharge event in response to the second control signal;

performing a charging operation in response to the confirmed over-discharge event;

counting a number of confirmed over-charge events and outputting a first count value corresponding to the number of confirmed over-charge events;

counting a number of confirmed over-discharge events and outputting a second count value corresponding to the number of confirmed over-discharge events; and

storing the first count value and the second count value.

10. The method according to claim 9 , wherein confirming the over-charge event comprises:

measuring a voltage of the battery; and

comparing the measured voltage of the battery to a first predetermined threshold voltage.

11. The method according to claim 10 , wherein performing the self-discharging operation in response to the confirmed over-charge event comprises:

generating a third control signal according to the comparison of the measured voltage and the first predetermined threshold voltage;

transmitting the third control signal to a recovery control device configured to discharge the battery in response to the third control signal.

12. The method according to claim 9 , wherein confirming the over-discharge event comprises:

measuring a voltage of the battery; and

comparing the measured voltage to a second predetermined threshold voltage.

13. The method according to claim 12 , wherein performing the self-charging operation in response to the confirmed over-discharge event comprises:

generating a fourth control signal according to the comparison of the measured voltage and the second predetermined threshold voltage; and

transmitting the fourth control signal to a charger device configured to charge the battery in response to the fourth control signal.

14. A system, comprising:

a host device;

a charger; and

a battery pack connected to the host device via a first I/O terminal, a second I/O terminal, and a third I/O terminal and connected to the charger via a fourth I/O terminal, wherein the battery pack comprises:

a protection control circuit configured to:

detect an over-charge event and generate a first control signal in response to the detected over-charge event; and

detect an over-discharge event and generate a second control signal in response to the detected over-discharge event; and

a fuel gauge circuit configured to receive the first control signal and second control signal and comprising:

a voltage sensor to detect a voltage of the battery;

a comparator system connected to the voltage sensor and configured to:

compare the detected voltage with a first predetermined voltage and generate a first comparator output according to the comparison, wherein the first comparator output indicates whether the detected over-charge event is a type-1 over-charge event or a type-2 over-charge event; and

compare the detected voltage with a second predetermined voltage and generate a second comparator output according to the comparison, wherein the second comparator output indicates whether the detected over-discharge event is a type-1 over-discharge event or a type-2 over-discharge event;

a plurality of counters connected to an output of the comparator system and configured to count a number of type-1 over-charge events and generate a corresponding first count value, count a number of type-2 over-charge events and generate a corresponding second count value, count a number of type-1 over-discharge events and generate a corresponding third count value, and count a number of type-2 over-discharge events and generate a corresponding fourth count value; wherein the plurality of counters is further configured to transmit the first, second, third, and fourth count values to the host device; and

a recovery control device connected to the fuel gauge circuit and configured to provide a self-discharging operation in response to the type-1 over-charge event.

15. The system according to claim 14 , wherein:

the over-charge event is the type-1 over-charge event if the detected voltage is greater than a first predetermined threshold voltage;

the over-charge event is the type-2 over-charge event if the detected voltage is less than the first predetermined threshold voltage;

the over-discharge event is the type-1 over-discharge event if the voltage is less than a second predetermined threshold voltage; and

the over-discharge event is the type-2 over-discharge event if the voltage is greater than the second predetermined threshold voltage.

16. The system according to claim 14 , wherein the recovery control device comprises a field-effect transistor comprising:

a gate terminal connected to the fuel gauge circuit and responsive to a third control signal;

a source terminal connected to a first terminal of the battery; and

a drain terminal connected to a second terminal of the battery.

17. The system according to claim 14 , wherein the charger is configured to charge the battery in response to the type-1 over-discharge event.

18. The system according to claim 14 , wherein the fuel gauge circuit further comprises:

a first output control circuit configured to generate a third control signal in response to the type-1 over-charge event and the first control signal; and

a second output control circuit configured to generate a fourth control signal in response to the type-1 over-discharge event and the second control signal.

19. The system according to claim 14 , wherein the battery pack further comprises:

a charge control device connected between the host system and the battery and responsive to the first control signal; and

a discharge control device connected between the host system and the battery and responsive to the second control signal.