CN114374237A - Charging device, charging method and mobile power supply - Google Patents

Abstract

The invention discloses a charging device, a charging method and a mobile power supply. The charging device includes: a controller, a linear charging module and a switching charging module. The controller is arranged to detect the battery voltage and determine the charging stage of the battery according to the battery voltage. During the precharge phase, the controller enables the linear charging module. In the constant current charging stage, the controller enables the switching charging module. Before the charging current drops to the reference threshold current in the constant voltage charging phase, the controller enables the switching charging module. After the charging current drops to the reference threshold current in the constant voltage charging phase, the controller enables the linear charging module. In this way, the advantages of the switching charging method and the linear charging method are fully utilized, and the charging efficiency is improved.

Description

A charging device, charging method and mobile power supply

technical field

The present invention relates to, but is not limited to, electronic technology, and more particularly, to a charging device, a charging method and a mobile power source.

Background technique

With the advancement of Internet of Things (IoT) technology and the gradual promotion of the application of smart wearable devices, the application of rechargeable lithium batteries has become increasingly widespread. Smart devices are smaller in size, such as smart watches, True Wireless Stereo (TWS, True Wireless Stereo) headphones, etc. The volume of smart devices poses different challenges to various technologies such as battery capacity, battery life, and battery capacity recovery (charging). Charging technologies include: optimizing battery state of charge (SOC, State of Charge) and capacity, management of device life, and key technologies such as maintaining battery state of health (SOH, State of Health) and extending battery life.

Figure 1 is a schematic diagram of the battery charging process in the related art. The current in Figure 1 generally refers to the average current entering the battery. As shown in Figure 1, the curve 11 represents the charging current curve, and the curve 12 represents the charging voltage curve. Generally, the charging curve can be It is divided into three stages: trickle charger or pre-charge stage, constant-current charge stage and constant-voltage charge stage.

During the trickle charge/precharge phase, that is, when the battery voltage is lower than the precharge voltage threshold VPRE, the battery is charged with a small charging current IPRE (also called precharge current).

In the constant current charging stage, that is, when the battery voltage is higher than the precharge voltage threshold VPRE but less than the battery rated voltage VREG, the battery is charged with a relatively large current ICHG (also called constant current charging current) to minimize the charging time.

In the constant voltage charging stage, that is, when the battery voltage reaches the battery rated voltage VREG, the voltage on the battery is maintained unchanged, and the charging current is gradually reduced until the charging current is lower than a set threshold ITER (cut-off current), and the charging is ended.

In order to avoid overcharging the battery, the total charging time can be set. When the whole charging process exceeds the charging time set by the system, even if the current has not decreased to the cut-off current ITER, the charging will be forcibly ended. Theoretically, the smaller the cut-off current ITER, the higher the capacity SOH recovered by the battery.

The charging method can be linear charging or switching charging. Linear charging devices are small, easy to use, low cost, and do not require any switching, however, when the charging current is large, the power consumption is high. Switching charging devices include energy storage elements (eg inductors, capacitors). As a result, switching charging devices take up more board space than linear charging devices, increasing cost and design complexity.

SUMMARY OF THE INVENTION

The present invention provides a charging device, a charging method and a mobile power supply, which can achieve high charging efficiency and maintain a healthy state of the battery.

According to one aspect of the present invention, there is provided a charging device including a controller, a linear charging module, and a switching charging module. The controller is configured to detect the battery voltage and charging current, and determine the charging stage of the battery based on the battery voltage. In the pre-charging stage, the controller enables the linear charging module to charge the battery in a linear charging manner. In the constant current charging stage, the controller enables the switching charging module to charge the battery in the switching charging mode. In the constant voltage charging stage, before the charging current drops to the reference threshold current, the controller enables the switching charging module to charge the battery in a switching charging mode. In the constant voltage charging stage, after the charging current drops to the reference threshold current, the linear charging module is enabled to charge the battery in a linear charging manner.

In one embodiment, in the constant voltage charging stage, when the charging current drops to the cut-off current, the controller turns off the linear charging module.

In one embodiment, when the battery voltage drops to a recharge voltage threshold, the controller enables the switch charging module to perform constant current charging on the battery in a switch charging manner.

In one embodiment, the controller is further configured to start a first timer, and the first timer is used to determine whether the precharge phase exceeds the precharge safety period.

In one embodiment, the controller is further configured to start a second timer, and the second timer is used for judging whether the constant current charging stage exceeds a safe duration of constant current charging.

In one embodiment, the controller is further configured to start a third timer, and the third timer is used to determine whether the charging current drops to the reference current threshold within a first preset safe period of time during the constant voltage charging stage .

In one embodiment, the controller is further configured to start a fourth timer, and the fourth timer is used to determine whether the charging current drops to the cut-off current within a second preset safe period of time during the constant voltage charging stage.

In one embodiment, the controller is further configured to start a fifth timer. The fifth timer is used for judging whether the constant voltage charging stage exceeds the safe duration of constant voltage charging.

In one embodiment, the controller is further configured to start a sixth timer, and the sixth timer is used to determine whether the charging duration exceeds the charging safety duration.

In one embodiment, the reference current threshold is lower than the charging current of the constant current charging stage.

According to another aspect of the present invention, a mobile power supply is provided. The mobile power supply includes a battery and the above-mentioned charging device.

According to yet another aspect of the present invention, a charging method is provided. The charging method includes: detecting that the battery voltage is lower than a pre-charging voltage threshold, and using a linear charging method to pre-charge the battery; detecting that the battery voltage reaches the pre-charging voltage threshold, using a switching charging method to perform constant current charging on the battery; Before the voltage reaches the rated voltage of the battery and the charging current drops to the reference threshold current, the battery is charged with constant voltage by switching charging; The battery is charged with constant voltage.

In one embodiment, the reference current threshold is less than the charging current in the constant current charging phase.

In one embodiment, the method further comprises: detecting that the battery voltage is equal to the rated voltage of the battery and the charging current drops to a cut-off current, stopping charging the battery.

In one embodiment, the method further includes: detecting that the battery voltage drops to a recharge voltage threshold, and using a switching charging method to charge the battery with a constant current.

In the charging device and charging method provided by the embodiments of the present invention, the switching charging method is adopted in the constant current charging stage, which improves the charging efficiency and reduces the power consumption. Using a linear charging method, the battery state of charge is optimized and the battery health is maintained.

Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the description, claims and drawings.

Description of drawings

The accompanying drawings are used to provide a further understanding of the technical solutions of the present invention, and constitute a part of the description. They are used to explain the technical solutions of the present invention together with the embodiments of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

FIG. 1 is a schematic diagram of a charging process of a battery in the related art.

FIG. 2 is a schematic diagram of a charging device according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of another charging device according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of the charging process of the battery in the present invention.

FIG. 5 is a flowchart of a charging method according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of another charging device according to an embodiment of the present invention.

FIG. 7 is a flowchart of another charging method according to an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application clearer, the embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that, the embodiments in the present application and the features in the embodiments may be arbitrarily combined with each other if there is no conflict.

FIG. 2 is a structural block diagram of a charging device provided by the present application. The charging device is connected to the system voltage VSYS to charge the battery. The system voltage VSYS may be direct current or alternating current, and the system voltage VSYS is, for example, 5V-9V. The system voltage VSYS is provided by, for example, USB, an adapter, and an external battery. In some embodiments, the charging device and the battery are provided in an electronic device, such as a mobile phone, a tablet computer, a smart watch, a True Wireless Stereo (TWS, True Wireless Stereo) headset, a music player, and the like. The battery is a rechargeable battery, such as a lithium-ion battery. In other embodiments, the charging device is an external accessory of the electronic device, the battery is used as a power source of the electronic device, and the battery can be disposed in the electronic device or a detachable battery of the electronic device. In other embodiments, the charging device and the battery constitute a mobile power source, such as a power bank.

The charging device includes a controller, a linear charging module and a switch charging module. The controller determines the charging process according to the initial voltage of the battery. The controller detects the battery voltage and charging current during the charging process, and selects one of the linear charging module and the switching charging module to charge the battery according to the battery voltage and charging current. The charging device also includes, for example, a current sensor and a voltage sensor. A current sensor is used to detect the charging current. The voltage sensor is used to detect the battery voltage. In some embodiments, the controller selects one of trickle charging, constant current charging and constant voltage charging according to the charging current and battery voltage, and enables one of the linear charging module and the switching charging module.

For the case where the initial voltage of the battery to be charged is less than the precharge voltage threshold VPRE, the charging process includes a trickle charging phase (precharging phase), a constant current charging phase and a constant voltage charging phase.

In the case where the initial voltage of the battery to be charged is greater than or equal to the precharge voltage threshold VPRE and less than the rated voltage of the battery, the charging process includes a constant current charging stage and a constant voltage charging stage.

When the initial voltage of the battery to be charged is the rated voltage of the battery, it is not necessary to charge the battery.

In the pre-charging stage, the controller enables the linear charging module to charge the battery in a linear charging manner. In the constant current charging stage, the controller enables the switching charging module to charge the battery in the switching charging mode. In the constant voltage charging stage, before the charging current drops to the reference threshold current, the controller enables the switching charging module to charge the battery in a switching charging mode. In the constant voltage charging stage, after the charging current drops to the reference threshold current, the controller enables the linear charging module to charge the battery in a linear charging manner.

The following description will be given by taking an example that the initial voltage of the battery to be charged is less than the precharge voltage threshold VPRE. In the trickle charging stage (when the battery voltage is lower than the precharge voltage threshold VPRE), the controller enables the linear charging module, and the linear charging module provides the precharge current IPRE to the battery. When the battery voltage rises to the precharge voltage threshold VPRE, the charging process enters the constant current charging stage, the controller controls the linear charging module to stop working and enables the switching charging module, which provides a constant charging current to the battery. When the battery voltage rises to the rated voltage, the charging process enters the constant voltage charging stage. After entering the constant voltage charging stage, the switching charging module provides a constant charging voltage to the battery, and the controller monitors the charging current. When the charging current decreases to the reference current threshold, the controller controls the switch charging module to stop working and enables the linear charging module, the linear charging module provides a constant charging voltage to the battery, and the controller continues to monitor the magnitude of the charging current. When the charging current decreases to the cut-off current ITER, the charging of the battery is stopped.

The present invention also provides a charging method, which includes: detecting that the battery voltage is lower than a pre-charging voltage threshold, pre-charging the battery by a linear charging method; detecting that the battery voltage reaches the pre-charging voltage threshold, using a switching charging method to charge the battery Perform constant current charging; it is detected that the battery voltage reaches the rated battery voltage and the charging current does not drop to the reference threshold current, and the battery is charged with constant voltage by switching charging; and it is detected that the battery voltage reaches the rated battery voltage and the charging current drops to the reference threshold value The battery is charged with constant voltage by means of linear charging. The reference current threshold is smaller than the charging current in the constant current charging stage. The method further includes stopping charging the battery upon detecting that the battery voltage is equal to the battery rated voltage and the charging current drops to a cut-off current.

FIG. 3 is a schematic diagram of another charging device according to an embodiment of the present application. The charging device 10 includes a controller 100, a switch charging module, a linear charging module, a battery 140, a current sensor 150, and a voltage sensor (not shown in the figure). The current sensor 150 is used to detect the magnitude of the charging current, and the voltage sensor is used to detect the voltage of the battery 140 .

The switch charging module includes a switch charging management 110 , a first transistor T1 , a second transistor T2 and an inductor L. In some embodiments, the first transistor T1 is a PMOS and the second transistor T2 is an NMOS. In other embodiments, the first transistor T1 is an NMOS, and the second transistor T2 is a PMOS. In still other embodiments, the first transistor T1 and the second transistor T2 are both NMOS or both are PMOS. The first electrode of the first transistor T1 is connected to the input terminal of the system voltage VSYS, the second electrode of the first transistor T1 is connected to the first electrode of the second transistor T2, and the second electrode of the second transistor T2 is grounded. The gates of the first transistor T1 and the second transistor T2 receive control signals provided by the switch charging management 110 . The first terminal A of the inductor L is connected to the second pole of the first transistor T1 and the first pole of the second transistor T2 , and the second terminal B of the inductor L is connected to the battery 140 . The switch charging management 110 controls the first transistor T1 and the second transistor T2 to be turned on in turn, and the charging current is provided to the battery 140 through the inductor L. For example, the switch charging management 110 provides a pulse width modulation (PWM) signal to the gates of the first transistor T1 and the second transistor T2 to modulate the charging current through the inductor L. FIG.

The linear charging module includes a linear charging management 120 and a third transistor T3, which is, for example, a PMOS. The first pole of the third transistor T3 is connected to the input terminal of the system voltage VSYS, and the second pole of the third transistor T3 is connected to the first terminal A of the inductor L. Optionally, the second pole of the third transistor T3 is connected to the second end B of the inductor L. The gate of the third transistor T3 receives the control signal provided by the linear charge management 120 . The magnitude of the charging current supplied to the battery 140 is controlled by the third transistor T3.

The controller 100 determines the charging process according to the initial voltage of the battery 140 , and selects the switching charging module and the linear charging module to charge the battery 140 according to the charging current and the voltage of the battery 140 during the charging process.

FIG. 5 is a flowchart of a charging method according to an embodiment of the present application. Figure 4 shows the battery voltage and charging current at various stages of the charging process. In FIG. 4 , the curve 41 is the charging current curve 41 during the charging process, and the curve 42 is the battery voltage curve during the charging process. The method for charging the battery by the charging device will be described below with reference to FIGS. 3-5 . The initial voltage of the battery 140 is lower than the precharge voltage threshold VPRE, and the controller 100 determines that the charging process includes a trickle charging (precharging) phase, a constant current charging phase, and a constant voltage charging phase.

Step S502 , in the trickle charging stage, the controller 100 enables the linear charging module, and the linear charging module charges the battery 140 in a trickle charging manner. In the trickle charging stage, the linear charging management 120 controls the magnitude of the current (ie, the charging current) flowing through the third transistor T3 to be the pre-charging current IPRE through the control signal. In some embodiments, the capacity of the battery 140 is C (in mAH), and the precharge current IPRE is between C/100 mA and C/10 mA. In the trickle charging stage, both the first transistor T1 and the second transistor T2 are in an off state.

As shown in FIG. 4, as the linear charging module trickles the battery 140, the voltage of the battery 104 increases. The controller 100 monitors the voltage of the battery 140 . In step S504, the controller 100 determines whether the voltage of the battery 104 rises to the precharge voltage threshold VPRE. If the voltage of the battery 104 is still below the precharge voltage threshold VPRE, the linear charging module continues to trickle charge the battery 140 . If the voltage of the battery 104 rises to the precharge voltage threshold VPRE, the constant current charging phase is entered.

In step S506, the controller 100 stops the linear charging module, enables the switching charging module, and the switching charging module performs constant current charging on the battery. The switching charging module provides charging current ICHG to the battery 104 . The first transistor T1 and the second transistor T2 are turned on in turn, and the charging current ICHG has a constant average value or a DC component, for example, 0.5C˜2C mA. In the constant current charging stage, the third transistor T3 is in an off state.

As shown in FIG. 4 , the voltage of the battery 104 continues to increase as the switching charging module performs constant current charging on the battery 140 . The controller 100 monitors the voltage of the battery 140 . In step S508, the controller 100 determines whether the voltage of the battery 104 increases to the battery rated voltage VREG. If the voltage of the battery 104 is still lower than the rated voltage VREG of the battery, the switch charging module continues to charge the battery 140 with a constant current. If the voltage of the battery 104 rises to the battery rated voltage VREG, the constant voltage charging phase is entered.

Step S510, the switch charging module performs constant voltage charging on the battery. As shown in Figure 4, during the constant voltage charging stage, the charging current gradually decreases.

In step S512, the controller 100 determines whether the charging current drops to the reference threshold current IREF. If the charging current is still greater than the reference threshold current IREF, the switch charging module continues to charge the battery with constant voltage. If the charging current drops to the reference threshold current IREF, the process proceeds to step S514. The reference threshold current IREF is smaller than the charging current ICHG in the constant current charging phase.

In step S514, the controller 100 stops switching the charging module, enables the linear charging module, and the linear charging module performs constant voltage charging on the battery. The switching charging module stops working, and the first transistor T1 and the second transistor T2 are in an off state. During the constant voltage charging of the battery by the linear charging module, the charging current continues to decrease.

In step S516, the controller 100 determines whether the charging current drops to the cut-off current ITER. If the charging current drops to the cut-off current ITER, the linear charging module stops working and charging ends. If the charging current is still greater than the cut-off current ITER, the linear charging module continues to charge the battery with constant voltage.

In some embodiments, the reference threshold current IREF is equal to ISYS/(1-VBAT/VSYS), where ISYS is equal to the operating current of the switching circuit plus the battery charging current ICHG. In some cases, VBAT and VSYS are very close. Then, when the charging process enters the constant voltage charging stage, the switching charging module is stopped, the linear charging module is enabled, and the linear charging module performs constant voltage charging on the battery.

In some embodiments, the switching charging management 110 controls the first transistor T1 and the second transistor T2 to be turned on in turn through a PWM signal. During the constant voltage charging stage, as the charging current decreases, the switching charging module changes from a continuous current mode , CCM) into the discontinuous current mode (Discontinuous Current Mode, DCM). In continuous current mode, the current on the inductor does not drop to 0, and in discontinuous current mode, the current on the inductor drops to 0. The reference threshold current IREF is set equal to the charging current value when the switching charging module enters the discontinuous current mode from the continuous current mode. Optionally, when the switching charging module transitions from the continuous current mode to the discontinuous current mode, the switching charging management 110 sends a signal to the controller 100, and in response to the signal, the controller 100 stops the switching charging module and enables the linear charging module. When the switching charging module enters the discontinuous current mode from the continuous current mode, stopping the switching charging module and starting the linear switching charging module can improve the charging efficiency.

FIG. 4 shows the above-mentioned charging process, as well as the charging current curve 41 and the battery voltage curve 42 during the charging process. As shown in Figure 4, the above charging process includes four stages: stage 1 (the trickle charging stage using the linear charging module), stage 2 (the constant current charging stage using the switching charging module), and stage 3 (the charging stage using the switching charging module) constant voltage charging stage), and stage 4 (constant voltage charging stage using a linear charging module).

FIG. 6 shows a charging device according to another embodiment of the present application. In FIG. 6 , the switch charge management 110 and the linear charge management 120 are integrated in the controller 100 , and the controller 100 provides control signals for the first transistor T1 , the second transistor T2 , and the third transistor T3 .

In some embodiments, the second pole of the third transistor T3 is connected to the second terminal B of the inductor L, that is, the second pole of the third transistor T3 is connected to the battery 140 (as shown in FIG. 6 ). In the constant current charging stage, the switch The charging module and the linear charging module can work at the same time.

In some embodiments, after charging is completed, the charging device is still connected to the system voltage VSYS, and the controller 100 monitors the voltage of the battery 140 . If the voltage of the battery 140 drops to the recharge voltage threshold VRCH, the charging device recharges the battery 140 (Re-Charge).

During the recharging process, the controller first enables the switch charging module, and the switch charging module performs constant current charging on the battery 140 . When the voltage of the battery 140 rises to the rated voltage VREG, the switching charging module performs constant voltage charging on the battery 140 . When the charging current drops to the reference threshold current IREF, the controller stops switching the charging module, enables the linear charging module, and the linear charging module performs constant voltage charging on the battery. When the charging current decreases to the cut-off current ITER, the controller stops the linear charging module, and the recharging process ends.

In the recharging process of other embodiments, the linear charging module first performs constant current charging on the battery 140 , and then performs constant voltage charging on the battery 140 .

In the recharging process of other embodiments, the switching charging module first performs constant current charging on the battery 140 , and then performs constant voltage charging on the battery 140 .

In the recharging process of other embodiments, the switching charging module first performs constant current charging on the battery 140 , and the linear charging module performs constant voltage charging on the battery 140 .

The above description is directed to the case where the initial voltage of the battery is less than the precharge voltage threshold VPRE. For the case where the initial voltage of the battery is greater than or equal to the precharge voltage threshold VPRE and less than the rated voltage VREG, the charging process includes a constant current charging stage and a constant voltage charging stage, that is, the trickle charging stage is not included. In the constant current charging stage, the controller 100 enables the switching charging module; in the constant voltage charging stage, the switching charging module is enabled before the charging current decreases to the reference threshold current IREF, and in the constant voltage charging stage, the charging current decreases to the reference threshold current IREF After that, the linear charging module is enabled; when the charging current decreases to the cut-off current ITER, the charging ends.

Switching charge management, linear charge management, and controllers described in conjunction with the herein may be used with general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gates designed to perform the functions described herein Arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, eg, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

In some embodiments, the charging device includes one or more timers. One of the timers is used to determine whether the trickle charge phase exceeds the safe time period for trickle charge. One of the timers is used to judge whether the constant current charging stage exceeds the safe duration of the constant current charging. One of the timers is used for judging whether the constant voltage charging stage exceeds the safe duration of constant voltage charging. One of the timers is used to judge whether the charging current drops to the reference current threshold within a preset time during the constant voltage charging phase. One of the timers is used to judge whether the charging current drops to the cut-off current within a preset time during the constant voltage charging stage. One of the timers is used to determine whether the charging process exceeds a predetermined safe time period. The controller is set to start the corresponding timer based on the battery voltage and charging current. Optionally, a timer for judging whether the trickle charging stage exceeds the pre-charge safety duration, a timer for judging whether the constant-current charging stage exceeds the constant-current charging safety duration, for judging the constant-voltage charging stage Whether the constant voltage charging safety time is exceeded, the charging timer can be the same timer.

FIG. 7 is a flowchart of a charging method provided by another embodiment of the present application. The charging device performing the method includes a first timer, a second timer, a third timer and a fourth timer.

The initial voltage of the battery is less than the precharge voltage threshold VPRE, and the power supply VSYS is connected. First, trickle charging is performed, the controller starts the first timer, enables the linear charging module, and the linear charging module performs trickle charging on the battery.

Step S702, the controller determines whether the battery voltage is less than the precharge voltage threshold VPRE. If the battery voltage is still less than the precharge voltage threshold VPRE, go to step S704. If the battery voltage rises to the precharge voltage threshold VPRE, the constant current charging stage is entered, the controller starts the second timer, enables the switch charging module, and proceeds to step S708.

Step S704, the linear charging module continues to perform trickle charging on the battery.

Step S706, the controller determines whether the first timer has timed out. If the first timer times out, for example, the first timer reaches a preset pre-charging safety time period, the process goes to step S730. If the first timer has not timed out, return to step S702.

Step S730, stop charging. Step S732, disconnect the power supply or restart the charging device.

In step S708, the battery is charged with a constant current by a switching charging method.

In step S710, the controller determines whether the battery voltage is less than the rated voltage of the battery.

If the battery voltage is still lower than the rated battery voltage, go to step S712. If the battery voltage rises to the rated voltage of the battery, the constant voltage charging stage is entered, and the controller starts a third timer and proceeds to step S714.

Step S712, the controller determines whether the second timer has timed out. If the second timer times out, for example, the second timer reaches the preset safe duration of constant current charging, go to step S730. If the second timer has not timed out, return to step S708.

In step S714, the battery is charged with constant voltage in a switching charging manner.

Step S716, the controller determines whether the charging current has dropped to the reference current threshold.

If the charging current is still greater than the reference current threshold, go to step S718. If the charging current is less than the reference current threshold, the controller starts a fourth timer, stops switching the charging module, enables the linear charging module, and proceeds to step S720.

Step S718, the controller determines whether the third timer has timed out. If the third timer times out, go to step S730. If the third timer has not timed out, return to step S714.

In step S720, the battery is charged with constant voltage in a linear charging manner.

Step S722, the controller determines whether the charging current is less than the cut-off current.

If the charging current is still greater than the cut-off current, go to step S724. If the charging current is less than the cut-off current, the controller stops the linear charging module and proceeds to step S726.

Step S724, the controller determines whether the fourth timer has timed out. If the fourth timer times out, go to step S730. If the fourth timer has not timed out, return to step S720.

Step S726, charging ends.

In step S728, it is determined whether the battery voltage drops below the recharge voltage threshold. If the battery voltage is still greater than the recharge voltage threshold, return to step S726. If the battery voltage is less than the recharge voltage threshold, return to step S708 to recharge the battery.

It should be noted that only one recharging method is shown in FIG. 7 , that is, constant current charging and constant voltage charging are performed by switching charging method, and in the constant voltage charging stage, the charging current drops to the reference current threshold and constant voltage is performed by linear charging method. Charge. It is also possible to use the switching charging method to charge the battery with constant current and constant voltage, or use the linear charging method to charge the battery with constant current and constant voltage, or use the switching charging method to charge the battery with constant current and linear charging. Charge the battery with constant voltage.

Although the embodiments disclosed in the present application are as above, the described contents are only the embodiments adopted to facilitate the understanding of the present application, and are not intended to limit the present application. Any person skilled in the art to which this application belongs, without departing from the spirit and scope disclosed in this application, can make any modifications and changes in the form and details of the implementation, but the scope of patent protection of this application must still be The scope defined by the appended claims shall prevail.

Claims (15)

1. A charging device, comprising: the charging device comprises a controller, a linear charging module and a switch charging module; wherein,

a controller configured to detect a battery voltage and a charging current, determine a charging phase of the battery based on the battery voltage:

a pre-charging stage, enabling a linear charging module to charge the battery in a linear charging mode;

in the constant current charging stage, a switch charging module is enabled to charge the battery in a switch charging mode;

in the constant-voltage charging stage, before the charging current is reduced to the reference threshold current, the switch charging module is enabled to charge the battery in a switch charging mode; and

and in the constant voltage charging stage, after the charging current is reduced to the reference threshold current, enabling the linear charging module to charge the battery in a linear charging mode.

2. The charging device of claim 1, the controller further configured to:

and in the constant-voltage charging stage, when the charging current is reduced to a cut-off current, the linear charging module is turned off.

3. The charging device of claim 2, the controller further configured to:

and when the voltage of the battery is reduced to a recharging voltage threshold value, enabling the switch charging module to perform constant-current charging on the battery in a switch charging mode.

4. The charging device of claim 1, the controller further configured to:

a first timer is started for determining whether the precharge phase exceeds a precharge safe duration.

5. The charging device of claim 1, the controller further configured to:

and starting a second timer for judging whether the constant-current charging stage exceeds the constant-current charging safe time length.

6. The charging device of claim 1, the controller further configured to:

and starting a third timer for judging whether the charging current is reduced to the reference current threshold value in a first preset safety duration in the constant voltage charging stage.

7. The charging device of claim 1, the controller further configured to:

and starting a fourth timer for judging whether the charging current is reduced to the cut-off current in a second preset safe time length in the constant voltage charging stage.

8. A charging arrangement as claimed in claim 1 or 2, the controller being further arranged to:

and starting a fifth timer for judging whether the constant voltage charging stage exceeds the constant voltage charging safety time length.

9. The charging device of claim 1, the controller further configured to:

and starting a sixth timer for judging whether the charging time length exceeds the charging safety time length.

10. The charging device of claim 1, wherein the reference current threshold is lower than a charging current of the constant current charging phase.

11. A mobile power supply, comprising: a battery and a charging device as claimed in any one of claims 1 to 10.

12. A method of charging, comprising:

detecting that the voltage of the battery is lower than a pre-charging voltage threshold value, and pre-charging the battery in a linear charging mode;

detecting that the voltage of the battery reaches a pre-charging voltage threshold value, and performing constant-current charging on the battery by adopting a switch charging mode;

detecting that the voltage of the battery reaches the rated voltage of the battery and the charging current is greater than the reference threshold current, and performing constant-voltage charging on the battery by adopting a switch charging mode; and

and detecting that the voltage of the battery reaches the rated voltage of the battery and the charging current drops to the reference threshold current, and performing constant-voltage charging on the battery by adopting a linear charging mode.

13. The method of claim 12, wherein the reference current threshold is less than a charging current of a constant current charging phase.

14. The method of claim 12, further comprising:

and stopping charging the battery when the battery voltage is detected to be equal to the rated voltage of the battery and the charging current drops to the cut-off current.

15. The method of claim 14, further comprising:

and detecting that the voltage of the battery is reduced to a recharging voltage threshold value, and performing constant-current charging on the battery by adopting a switch charging mode.

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