Method and apparatus for charging a battery

Abstract

The invention discloses a method and apparatus for charging a battery. The method comprises the following steps: in response to the access of power supply equipment, calculating the line resistance from the output end of the power supply equipment to the input end of a charge pump according to the output voltage of the power supply equipment, the input voltage of the charge pump and the input current of the charge pump; calculating the resistance of the charging circuit board according to the output voltage of the charge pump and the battery voltage and the battery charging current sensed by the voltameter; acquiring a constant-voltage stage charge pump output voltage according to the charging circuit board resistance; acquiring a corresponding charge pump input voltage to be adjusted according to the charge pump output voltage in the constant voltage stage; and adjusting the output voltage of the power supply equipment according to the input voltage of the charge pump to be adjusted and the line resistance so as to charge the battery. The line resistance from the output end of the power supply equipment to the input end of the charge pump is calculated, the input voltage of the charge pump is predicted according to the line resistance, large-current transverse-current charging can be carried out in advance, and the charging time is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery charging, and in particular to a method and a device for charging a battery. Background Art

[0002] In the charging process, especially fast charging, such as the charging environment that introduces a charge pump, the influence of various resistors needs to be considered. At present, in the fast charging stage, due to the voltage difference Vpcb = I Rpcb, taking the charging situation of large current I of 10A as an example, if the resistance Rpcb of the PCB board is 20mΩ, the battery full voltage is 4400mV, if the influence of Rpcb is ignored, the output voltage of the charge pump will remain at 4400mV. However, in fact, the battery voltage is only 4200mV, causing the battery to enter the constant voltage charging stage in advance at 4200mV. At this time, the battery is not fully charged, but the system has already considered it to be close to full charge and begins to reduce the charging current, resulting in a longer actual charging time. Summary of the invention

[0003] The present invention provides a method and device for charging a battery, which can solve the problem that the battery enters the constant voltage charging stage prematurely during fast charging. Improving these problems will increase the charging speed and save charging time.

[0004] In one aspect of the present invention, a method for charging a battery is provided. The method includes: in response to the access of a power supply device, according to the output voltage of the power supply device, the charge pump input voltage and the charge pump input current, calculating the line resistance from the output end of the power supply device to the input end of the charge pump; according to the charge pump output voltage and the battery voltage and battery charging current sensed by the fuel gauge, calculating the charging circuit board resistance; obtaining the charge pump output voltage in the constant voltage stage according to the charging circuit board resistance; obtaining the corresponding charge pump input voltage to be adjusted according to the charge pump output voltage in the constant voltage stage; and adjusting the output voltage of the power supply device according to the charge pump input voltage to be adjusted and the line resistance to charge the battery.

[0005] In some embodiments, calculating the line resistance from the output end of the power supply device to the input end of the charge pump based on the output voltage of the power supply device, the charge pump input voltage and the charge pump input current includes: obtaining the measured charge pump input voltage and the charge pump input current; and dividing the difference between the output voltage of the power supply device and the charge pump input voltage by the charge pump input current to calculate the line resistance from the output end of the power supply device to the input end of the charge pump.

[0006] In some embodiments, calculating the charging circuit board resistance based on the charge pump output voltage and the battery voltage and battery charging current sensed by the fuel gauge includes: obtaining the measured charge pump output voltage; and dividing the difference between the charge pump output voltage and the battery voltage by the battery charging current to obtain the charging circuit board resistance.

[0007] In some embodiments, obtaining the charge pump output voltage in the constant voltage stage according to the charging circuit board resistance includes: adding the product of the battery charging current and the charging circuit board resistance to a preset battery full charge voltage to calculate the charge pump output voltage in the constant voltage stage.

[0008] In some embodiments, obtaining the corresponding charge pump input voltage to be adjusted based on the charge pump output voltage in the constant voltage stage includes: obtaining an equivalent numerical value of the charge pump based on an equivalent working mode of the charge pump; and taking the product of the charge pump output voltage in the constant voltage stage and the equivalent numerical value as the charge pump input voltage to be adjusted.

[0009] In some embodiments, adjusting the output voltage of the power supply device according to the charge pump input voltage to be adjusted and the line resistance includes: obtaining the adjusted output voltage of the power supply device by adding the charge pump input voltage to be adjusted to the product of the charge pump input current corresponding to the charge pump input voltage to be adjusted and the line resistance.

[0010] In some embodiments, the method further includes: in response to access of the power supply device, determining whether the power supply device supports a fast charging protocol; if the fast charging protocol is supported, setting the output voltage of the power supply device according to the current battery voltage.

[0011] In another aspect of the present invention, a device for charging a battery is provided. The device includes: a processor, configured to calculate the line resistance from the output end of the power supply device to the input end of the charge pump according to the output voltage, charge pump input voltage and charge pump input current of the power supply device in response to the access of the power supply device; obtain the charge pump output voltage in the constant voltage stage according to the resistance of the charging circuit board, obtain the corresponding charge pump input voltage to be adjusted according to the charge pump output voltage in the constant voltage stage, and adjust the output voltage of the power supply device according to the charge pump input voltage to be adjusted and the line resistance to charge the battery. The power supply device is configured to provide the output voltage of the power supply device; the charge pump is electrically coupled to the power supply device and configured to obtain the charge pump input voltage and the charge pump input current; the fuel gauge is arranged on the battery protection board and configured to sense the battery voltage and the battery charging current, and the battery protection board is electrically coupled to the charge pump.

[0012] According to the present invention, a fuel meter is designed on a battery protection board, and the battery voltage and battery charging current without the influence of line resistance can be obtained through the fuel meter, so as to calculate the voltage in the constant voltage stage, thereby avoiding the voltage being too low when entering the constant voltage stage; by calculating the line resistance from the output end of the power supply device to the input end of the charge pump, the input voltage of the charge pump is predicted according to the line resistance, so that high-current cross-current charging can be started earlier, saving charging time. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A flowchart of a method for charging a battery according to an embodiment of the present invention; Figure 2 The present invention is a block diagram of a device for charging a battery according to an embodiment of the present invention. DETAILED DESCRIPTION

[0014] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0015] In the existing technology, the influence of the PCB board resistance is ignored during fast charging, and there is a problem of assuming that the battery is close to full charge in advance and entering the constant voltage charging stage, which in turn causes the charging time to be extended.

[0016] In order to solve at least the above technical problems, the present disclosure provides a method for charging a battery, wherein a fuel gauge is designed on a battery protection board, and the battery voltage and battery charging current without the influence of line resistance can be obtained through the fuel gauge, so as to calculate the voltage in the constant voltage stage, and avoid the voltage entering the constant voltage stage being too low. In addition, by calculating the line resistance from the output end of the power supply device to the input end of the charge pump, the input voltage of the charge pump is predicted according to the line resistance, so that high-current cross-current charging can be entered early, saving charging time.

[0017] Hereinafter, the technical solution according to the present disclosure will be described with reference to specific embodiments and in conjunction with the accompanying drawings.

[0018] Figure 1 is a flow chart showing a method 100 for charging a battery according to an embodiment of the present disclosure. Figure 1 The method 100 includes the following steps 102 to 110.

[0019] In step 102 , in response to the connection of the power supply device, the line resistance from the output end of the power supply device to the input end of the charge pump is calculated according to the output voltage of the power supply device, the charge pump input voltage and the charge pump input current.

[0020] In some embodiments, the measured charge pump input voltage and charge pump input current are obtained, and the difference between the output voltage of the power supply device and the charge pump input voltage is divided by the charge pump input current to calculate the line resistance from the output end of the power supply device to the input end of the charge pump. In this way, the influence of the charging line resistance and the contact resistance of the input end is correctly calculated, and the equivalent line resistance is accurately obtained.

[0021] In some embodiments, in response to the access of a power supply device, it is determined whether the power supply device supports a fast charging protocol. If the power supply device supports the fast charging protocol, the output voltage of the power supply device is set according to the current battery voltage.

[0022] In step 104, the charging circuit board resistance is calculated based on the charge pump output voltage and the battery voltage and battery charging current sensed by the fuel gauge.

[0023] In some embodiments, the measured charge pump output voltage is obtained, and the difference between the charge pump output voltage and the battery voltage is divided by the battery charging current to obtain the charging circuit board resistance.

[0024] In step 106, the output voltage of the charge pump in the constant voltage stage is obtained according to the resistance of the charging circuit board.

[0025] In some embodiments, the product of the battery charging current and the resistance of the charging circuit board is added to the preset battery full-charge voltage to calculate the charge pump output voltage in the constant voltage stage. In this way, the current battery voltage can be correctly detected, and the influence of the contact resistance introduced by the PCB routing battery socket, etc. cannot be accurately calculated, and the situation of misjudging the battery entering the constant voltage stage and reducing the high current charging time, resulting in an increase in charging time, can be prevented or ignored.

[0026] In step 108, the corresponding charge pump input voltage to be adjusted is obtained according to the charge pump output voltage in the constant voltage stage.

[0027] In some embodiments, an equivalent value of the charge pump is obtained according to the equivalent working mode of the charge pump, and the product of the charge pump output voltage in the constant voltage stage and the equivalent value is used as the charge pump input voltage to be adjusted. In this way, the desired charge pump input voltage to be adjusted can be obtained by adjusting the output voltage of the power supply device, and high-current cross-current charging can be started earlier, saving charging time.

[0028] In step 110, the output voltage of the power supply device is adjusted according to the charge pump input voltage to be adjusted and the line resistance to charge the battery.

[0029] In some embodiments, the adjusted output voltage of the power supply device is obtained by adding the product of the charge pump input current corresponding to the charge pump input voltage to be adjusted and the line resistance to the charge pump input voltage to be adjusted.

[0030] Figure 2 2 is a schematic diagram showing an apparatus 200 for charging a battery according to an embodiment of the present disclosure. The apparatus 200 includes a processor. In some embodiments, the apparatus may further include a power supply device, a charge pump, and a fuel gauge.

[0031] The processor is configured to calculate the line resistance from the output end of the power supply device to the input end of the charge pump according to the output voltage of the power supply device, the charge pump input voltage and the charge pump input current in response to the access of the power supply device. The processor is configured to calculate the charging circuit board resistance according to the charge pump output voltage and the battery voltage and battery charging current sensed by the fuel gauge. The processor is configured to obtain the charge pump output voltage in the constant voltage stage according to the charging circuit board resistance. The processor is configured to obtain the corresponding charge pump input voltage to be adjusted according to the charge pump output voltage in the constant voltage stage. In addition, the processor is configured to adjust the output voltage of the power supply device according to the charge pump input voltage to be adjusted and the line resistance to charge the battery.

[0032] It should be understood that the processor may be further configured to execute each corresponding step or action in the method described in the above embodiment, which will not be described in detail here.

[0033] In some embodiments, the power supply device is configured to provide an output voltage of the power supply device. In addition, the charge pump is electrically coupled to the power supply device and configured to obtain the charge pump input voltage and the charge pump input current. In addition, the fuel gauge is disposed on a battery protection board and is configured to sense the battery voltage and the battery charging current, and the battery protection board is electrically coupled to the charge pump.

[0034] Reference Figure 2 In this embodiment, the power supply device is a charger, the overvoltage protection module is OVP, the charging interface is TYPE-C, and the fuel gauge is arranged on the battery protection board. The power supply device and the charging interface are connected via a charging cable, and the charging interface, the overvoltage protection module, the charge pump and the battery protection board are connected via PCB wiring.

[0035] The power supply device can obtain the output voltage Vadapt of the power supply device, the ADC detection in the charge pump can obtain the charge pump input voltage Vbus and the charge pump input current Ibus, and the fuel meter can obtain the battery voltage Vbat and the battery charging current Icharge.

[0036] During the fast charging process, the charging environment of the charge pump is introduced. It is necessary to consider the influence of the charge pump output voltage Vout pin to the PCB wiring on the battery and the contact resistance between the battery and the PCB board, as well as the influence of the charging line, USB socket and wiring resistance on the PCB that connects the output end of the power supply device to the input end of the charge pump. In order to accurately calculate the line resistance of the PCB wiring and the contact resistance Rpcb between the battery and the PCB board, the hardware design is to design the fuel gauge on the battery protection board. The voltage measured by the fuel gauge is the battery cell voltage at the battery end. At this time, the most realistic battery voltage Vbat and battery charging current Icharge can be measured. During the charging process, as the output voltage of Vout increases, the charging current gradually increases, so Rpcb = (Vout- Vbat) / Icharge. After obtaining Rpcb, the output value of the constant voltage stage V'out = Vbatmax + Icharge can be obtained. Rpcb, where Vbatmax is the fully charged voltage of the battery. Considering the influence of Rpcb, the output of Vout in the constant voltage stage is greater than Vbatmax, so as to avoid being mistaken for the constant voltage stage when the battery voltage is lower than Vbatmax, thereby reducing the charging time.

[0037] Regarding the confirmation of Rline line resistance, there is a voltage difference between the output voltage Vadapt of the power supply device and the Vbus end of the charge pump: Rline = Vline / Iline, Vline = Vadapt - Vbus. The charge pump fast charge must take into account the influence of Rline when adjusting the output voltage of the charger, so that the desired Vbus voltage can be obtained more quickly. The charge pump adjusts the charging current by adjusting the input Vbus voltage, Vout = Vbus / n, Icharge = n Ibus, the current charge pump working equivalent mode is 4:1, 3:1, 2:1, 1:1, and the corresponding n values ​​are 4, 3, 2, and 1. Considering the influence of Rline, the expected Vbus voltage can be obtained faster, Vbus = Vadapt – Ibus Rline. Rline can be obtained by calculation: Rline = (Vadapt -Vbus) / Ibus.

[0038] Regarding the method flow of this embodiment, after inserting the charger, the main control can obtain whether the current power supply device supports the PPS fast charging protocol through the protocol chip. If it supports the PPS fast charging protocol, the output voltage Vadapt and the maximum output current of the power supply device are set according to the current battery voltage.

[0039] In summary, the method and device for charging a battery provided by the present invention designs a fuel meter on a battery protection board, and can obtain the battery voltage and battery charging current without the influence of line resistance through the fuel meter, so as to calculate the voltage in the constant voltage stage, and avoid the voltage entering the constant voltage stage being too low; by calculating the line resistance from the output end of the power supply device to the input end of the charge pump, the input voltage of the charge pump is predicted according to the line resistance. In this way, the fuel meter on the protection board measures the real voltage value without the influence of the line resistance, and the fuel meter will not measure the overvoltage (voltage greater than the maximum value of the nominal voltage) during the charging process. By accurately testing the battery voltage to prevent voltage misjudgment, it is possible to enter high-current cross-current charging early, saving charging time.

[0040] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for charging a battery, characterized in that: include: In response to the connection of the power supply device, the line resistance from the output end of the power supply device to the input end of the charge pump is calculated according to the output voltage of the power supply device, the charge pump input voltage and the charge pump input current; Calculating the charging circuit board resistance based on the charge pump output voltage and the battery voltage and battery charging current sensed by the fuel gauge; Obtaining the output voltage of the charge pump in the constant voltage stage according to the resistance of the charging circuit board; Acquiring a corresponding charge pump input voltage to be adjusted according to the charge pump output voltage in the constant voltage stage; as well as The output voltage of the power supply device is adjusted according to the charge pump input voltage to be adjusted and the line resistance to charge the battery.

2. The method according to claim 1, characterized in that Calculating the line resistance from the output end of the power supply device to the input end of the charge pump according to the output voltage of the power supply device, the charge pump input voltage, and the charge pump input current includes: Acquiring the measured charge pump input voltage and the charge pump input current; and The difference between the output voltage of the power supply device and the input voltage of the charge pump is divided by the input current of the charge pump to calculate the line resistance from the output end of the power supply device to the input end of the charge pump.

3. The method according to claim 1, characterized in that Calculating the charging board resistance based on the charge pump output voltage and the battery voltage and battery charge current sensed by the fuel gauge is: Acquiring the measured output voltage of the charge pump; and The difference between the charge pump output voltage and the battery voltage is divided by the battery charging current to obtain the charging circuit board resistance.

4. The method according to claim 3, characterized in that Acquiring the charge pump output voltage in the constant voltage stage according to the charging circuit board resistance includes: The product of the battery charging current and the charging circuit board resistance is added to the preset battery full-charge voltage to calculate the charge pump output voltage in the constant voltage stage.

5. The method according to claim 1, characterized in that Acquiring the corresponding charge pump input voltage to be adjusted according to the charge pump output voltage in the constant voltage stage includes: Acquiring an equivalent value of the charge pump according to an equivalent working mode of the charge pump; and The product of the charge pump output voltage in the constant voltage stage and the equivalent value is used as the charge pump input voltage to be adjusted.

6. The method according to claim 1, characterized in that Adjusting the output voltage of the power supply device according to the charge pump input voltage to be adjusted and the line resistance comprises: The adjusted output voltage of the power supply device is obtained by adding the product of the charge pump input current corresponding to the charge pump input voltage to be adjusted and the line resistance to the charge pump input voltage to be adjusted.

7. The method according to claim 1, characterized in that Also includes: In response to the access of the power supply device, determining whether the power supply device supports the fast charging protocol; If the fast charging protocol is supported, the output voltage of the power supply device is set according to the current battery voltage.

8. A device for charging a battery, characterized in that: include: The processor is configured as: In response to the connection of the power supply device, the line resistance from the output end of the power supply device to the input end of the charge pump is calculated according to the output voltage of the power supply device, the charge pump input voltage and the charge pump input current; Calculating the charging circuit board resistance based on the charge pump output voltage and the battery voltage and battery charging current sensed by the fuel gauge; Obtaining the output voltage of the charge pump in the constant voltage stage according to the resistance of the charging circuit board; Acquiring a corresponding charge pump input voltage to be adjusted according to the charge pump output voltage in the constant voltage stage; as well as The output voltage of the power supply device is adjusted according to the charge pump input voltage to be adjusted and the line resistance to charge the battery.

9. The device according to claim 8, characterized in that Also includes: A power supply device, configured to provide an output voltage of the power supply device; a charge pump, electrically coupled to the power supply device and configured to obtain the charge pump input voltage and the charge pump input current; The fuel gauge is disposed on a battery protection board and is configured to sense the battery voltage and the battery charging current. The battery protection board is electrically coupled to the charge pump.

10. The device according to claim 9, characterized in that A charging interface and an over-current protection module are provided between the charge pump and the power supply device; The power supply device is connected to the charging interface via a charging cable, and the charging interface, the overcurrent protection module, the charge pump and the battery protection board are connected via PCB wiring.

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