SOLAR CHARGER FOR CHARGING POWER BATTERY

• US 20120299529A1
• Filed: 06/29/2012
• Published: 11/29/2012
• Est. Priority Date: 12/31/2009
• Status: Active Grant

• Current Assignee: BYD Company Limited
• Original Assignee: BYD Company Limited, Shenzhen BYD Auto R&D Company Limited
• Inventors: Liang, Shulin, Zhang, Jianhua, GUO, Guangxi, Xu, Yang
• Granted Patent: US 10,270,282 B2
• Time in Patent Office: Days
• US Class Current: 320/101
• CPC Class Codes: H01L 31/042 PV modules or arrays of single PV cells supporting structures for PV modules H02S20/00
• CPC Class Codes: H01M 10/465 with solar battery as charging system
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A solar charger for charging a power battery is provided, comprising: a photo-sensitive unit configured to detect light intensity; a charging unit configured to receive a voltage transformed from solar energy and to boost the voltage for charging the power battery; a switch unit coupled between the charging unit and the power battery and configured to disconnect the charging unit from the power battery or connect the charging unit with the power battery; and a control unit coupled to each of the photo-sensitive unit, the switch unit, and the charging unit, and configured to switch on the charging unit and the switch unit when the light intensity is higher than a first predetermined value to charge the power battery.

Claims

1. A solar charger for charging a power battery, comprising:

a photo-sensitive unit configured to detect light intensity;

a charging unit configured to receive a voltage transformed from solar energy and to boost the voltage for charging the power battery;

a switch unit coupled between the charging unit and the power battery, and configured to disconnect the charging unit from the power battery or connect the charging unit with the power battery; and

a control unit coupled to each of the photo-sensitive unit, the switch unit, and the charging unit, and configured to switch on the charging unit and the switch unit when the light intensity is higher than a first predetermined value to charge the power battery.

2. The solar charger of claim 1, wherein the control unit is further configured to monitor the voltage of the power battery during charging of the power battery, and to switch off the charging unit and the switch unit when the voltage of the power battery reaches a saturation value.

3. The solar charger of claim 1, further comprising:

a power supply unit coupled to the control unit, and configured to receive and stabilize the voltage transformed from the solar energy to power the control unit,

wherein the control unit operates when the voltage transformed from the solar energy reaches a second predetermined value.

4. The solar charger of claim 3, wherein the second predetermined value is no less than 12 V.

5. The solar charger of claim 2, wherein the control unit is further configured to periodically switch on the switch unit to detect a current voltage of the power battery after the voltage of the power battery reaches a saturation value, and to switch on the charging unit and the switch unit to charge the power battery when the current voltage of the power battery is lower than the saturation value and the light intensity detected by the photo-sensitive unit is higher than the first predetermined value.

6. The solar charger of claim 5, wherein a periodic time for periodically switching on the switch unit ranges from about 10 minutes to about 50 minutes.

7. The solar charger of claim 1, wherein the control unit is further configured to periodically compare a current light intensity detected by the photo-sensitive unit with the first predetermined value, to switch off the charging unit and the switch unit if the current light intensity is lower than the first predetermined value, and to switch on the charging unit and the switch unit if the current light intensity is higher than the first predetermined value.

8. The solar charger of claim 7, wherein a periodic time for periodically comparing the light intensity with the first predetermined value ranges from about 0.5 minute to about 10 minutes.

9. The solar charger of claim 8, wherein the control unit is further configured to communicate with an external control device and to control the charging unit and the switch unit according to instructions from the external control device.

10. The solar charger of claim 9, wherein the control unit is further configured to switch off the charging unit and the switch unit if the control unit receives instructions of fast or slow charging.

11. The solar charger of claim 1, further comprising:

a cooling unit coupled to the control unit, and configured to cool the solar charger when a temperature of the solar charger detected by the control unit reaches a third predetermined value.

12. The solar charger of claim 11, wherein the third predetermined value ranges from about 40°

C. to about 100°

C.

13. The solar charger of claim 1, wherein the first predetermined value is no less than 50 lux.

14. The solar charger of claim 1, wherein the charging unit comprises:

a first capacitor having a first end coupled to a positive input terminal of the solar charger and a second end coupled to a negative input terminal of the solar charger;

a first inductance having a first end coupled to the positive input terminal of the solar charger;

a first diode having a positive end coupled to a second end of the first inductance;

a MOSFET having a gate electrode coupled to the control unit, a drain electrode coupled to the second end of the first inductance, and a source electrode coupled to the second end of the first capacitor; and

a second capacitor having a first end coupled to a negative end of the first diode and a second end coupled to the second end of the first capacitor.

15. The solar charger of claim 14, further comprising:

a second diode having a positive end coupled to the positive input terminal of the solar charger and a negative end coupled to a positive input end of the charging unit.

16. The solar charger of claim 14, further comprising:

a third diode having a positive end coupled to an output end of the switch unit and a negative end coupled to the power battery.

17. The solar charger of claim 14, further comprising:

a first current sensor configured to detect an input current at the positive input end of the charging unit, wherein the control unit adjusts a duty ratio of the MOSFET according to the input current detected by the first current sensor.

18. The solar charger of claim 17, further comprising:

a second current sensor configured to detect an output current at an output end of the charging unit, wherein the control unit determines a charging efficiency of the solar charger according to the output current detected by the second current sensor.