Battery Charging Method and Device

• US 20110266998A1
• Filed: 01/20/2010
• Published: 11/03/2011
• Est. Priority Date: 01/21/2009
• Status: Active Grant

• Current Assignee: Actions (Zhuhai) Technology Co., Limited
• Original Assignee: Actions Semiconductor Company Limited
• Inventors: Xiao, Lirong
• Granted Patent: US 8,890,486 B2
• Time in Patent Office: Days
• US Class Current: 320/107
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method and apparatus for charging a battery is provided. The apparatus includes: a constant current circuit, a constant voltage circuit and a control circuit. The control circuit is adapted to control the constant current circuit to perform constant current charging to the battery; after a battery voltage during the constant current charging reaches a preset charging limited voltage, control the constant voltage circuit to perform constant voltage charging to the battery; after a charging current during the constant voltage charging becomes smaller than or equal to a predetermined threshold, control the battery to be charged by pulse charging until an open circuit voltage of the battery is larger than or equal to a preset voltage threshold.

Claims

1. An apparatus for charging a battery, comprising:

a constant current circuit,

a constant voltage circuit; and

a control circuit;

wherein the control circuit is adapted to

control the constant current circuit to perform constant current charging to the battery;

after a battery voltage during the constant current charging reaches a preset charging limited voltage, control the constant voltage circuit to perform constant voltage charging to the battery;

after a charging current during the constant voltage charging becomes smaller than or equal to a predetermined threshold, control the battery to be charged by pulse charging until an open circuit voltage of the battery is larger than or equal to a preset voltage threshold.

2. The apparatus of claim 1, further comprising:

a clock circuit;

wherein the control circuit further comprises;

a first unit, adapted to stop the charging to the battery and trigger the clock circuit to start timing;

a second unit, adapted to, when a timing period reaches a preset off time, clear the timing of the clock circuit and determine whether an open circuit voltage of the battery is larger than or equal to the preset voltage;

if the open circuit voltage is larger than or equal to the preset voltage, terminate the charging;

otherwise, control the constant voltage circuit to perform the constant voltage charging to the battery and meanwhile trigger the clock circuit to start timing, and when a charging time reaches a predetermined pulse-charging-on time, clear the timing of the clock circuit, and trigger the first unit to stop charging the battery and to trigger the clock circuit to start timing.

3. The apparatus of claim 1, further comprising

a switch circuit;

wherein

an input port of the switch circuit is connected with a source port,

a control port of the switch circuit is connected with the control circuit,

a first output port of the switch circuit is connected with the constant current circuit and

a second output port of the switch circuit is connected with the constant voltage circuit;

the control circuit is adapted to control the input port of the switch circuit to be uniquely connected with the first output port to control the constant current circuit to perform the constant current charging to the battery;

control the input port of the switch circuit to be uniquely connected with the second output port to control the constant voltage circuit to perform the constant voltage charging to the battery.

4. The apparatus of claim 3, further comprising a charging source connected with the source port.

5. The apparatus of claim 1, wherein a voltage used when the constant voltage circuit performs the constant voltage charging to the battery is the charging limited voltage.

6. The apparatus of claim 1, wherein the charging limited voltage is 4.2V.

7. The apparatus of claim 1, wherein the pulse-charging-on time decreases with increase of the number of times that the charging is stopped during the pulse charging.

15. The apparatus of claim 2, further comprising:

a switch circuit;

wherein

an input port of the switch circuit is connected with a source port,

a control port of the switch circuit is connected with the control circuit,

a first output port of the switch circuit is connected with the constant current circuit and

a second output port of the switch circuit is connected with the constant voltage circuit;

the control circuit is adapted to control the input port of the switch circuit to be uniquely connected with the first output port to control the constant current circuit to perform the constant current charging to the battery;

control the input port of the switch circuit to be uniquely connected with the second output port to control the constant voltage circuit to perform the constant voltage charging to the battery.

16. The apparatus of claim 15, further comprising a charging source connected with the source port.

17. The apparatus of claim 2, wherein a voltage used when the constant voltage circuit performs the constant voltage charging to the battery is the charging limited voltage.

8. A method for charging a battery, comprising:

a) performing constant current charging to the battery;

b) performing constant voltage charging after a battery voltage during the constant current charging reaches a charging limited voltage of the battery;

c) after a charging current during the constant voltage charging becomes smaller than or equal to a predetermined threshold, performing pulse charging to the battery until an open circuit voltage of the battery is larger than or equal to a preset voltage threshold.

9. The method of claim 8, wherein the performing the pulse charging to the battery until the open circuit voltage of the battery is larger than or equal to the preset voltage threshold comprises:

c1) stopping charging the battery;

c2) when an off time that the charging is stopped reaches a preset off time, determining whether the open circuit voltage of the battery is larger than or equal to the preset voltage threshold;

if the open circuit voltage of the battery is larger than or equal to the preset voltage threshold, terminating the charging;

otherwise, performing the constant voltage charging to the battery, and returning to step C1 when a charging time reaches a pulse-charging-on time.

10. The method of claim 9, wherein the performing the constant voltage charging to the battery comprises performing the constant voltage charging to the battery with the charging limited voltage.

11. The method of claim 9, wherein the preset off time is 1 ms to 10 s.

12. The method of claim 9, wherein the pulse-charging-on time decreases with increase of the number of times that the charging is stopped during the pulse charging.

13. The method of claim 8, wherein the charging limited voltage is 4.2V.

14. The method of claim 13, wherein the pulse-charging-on time is not less than 1 second.