CN101986509B - charger - Google Patents

Abstract

The invention relates to a charger, in particular to a lithium battery charger, which can realize the quick charging of a lithium battery and comprises a shell and an operation panel, wherein a groove for placing a rechargeable battery is arranged on the shell, an inner cavity formed by the shell comprises a charging circuit, the charging circuit has a quick charging mode and charges the rechargeable battery with large current, the charging circuit also has a normal charging mode and charges the rechargeable battery with normal current, and the switching of the two charging modes is controlled by a control circuit. The charger of the invention provides an ultra-fast charging scheme which has a selectable charging mode and can be controlled by depending on the temperature change of the battery, and can realize that the charging power can be output in excess under the low-power and proper temperature change trend so as to realize that the battery can be safely provided with certain capacity (energy) in a short time to complete certain amount of work.

Description

charger

technical field

The present invention relates to a charger, in particular to a lithium battery charger, which can realize fast charging of lithium batteries.

Background technique

When customers use lithium batteries, the following situations generally occur: when a certain amount of work needs to be completed or a small part of work is left to be completed, the battery pack is found to be insufficient, and the user needs a small part of the capacity (such as a% of the battery capacity) to complete the work (no need for a full capacity battery), and hope that there is a charger mode that can complete the charging process of a% of the battery capacity in a very short time, such as 100S-200S. However, current fast-charging Li-ion battery chargers are expensive to design and have poor mode selectivity.

Contents of the invention

     The technical problem to be solved by the present invention is to overcome the defects in the prior art, realize low cost, and provide a charger with a selectable charging mode, so that the battery can be safely given a certain capacity (energy) over a short period of time. Complete a certain amount of work.

     In order to solve the above technical problems, the present invention provides a charger, which includes a casing and an operation panel. A slot for placing a rechargeable battery is provided on the casing. The inner cavity formed by the casing contains a charging circuit, and the charging circuit has a fast charging mode. The rechargeable battery is charged with a large current, and the charging circuit also has a normal charging mode, and the rechargeable battery is charged with a normal current, and the switching between the two charging modes is controlled by the control circuit.

     The charging current in the fast charging mode is greater than that in the normal charging mode, and the charging time is shorter than that in the normal charging mode.

     The switching between the fast charging mode and the normal charging mode can be controlled by the control circuit according to the real-time monitoring of the current temperature and voltage value of the rechargeable battery by the temperature detection circuit and the voltage detection circuit. It can also be triggered by the control switch on the operation panel and manually selected by the user. .

     Beneficial effects achieved by the present invention: the charger of the present invention provides optional charging modes, one of which includes: an ultra-fast charging scheme relying on battery temperature changes and battery control, the charger is designed with optional fast Charging mode, under low power and suitable temperature change trend, it can output charging power in excess to charge the battery to a% capacity in a short time, which is enough to complete urgently needed work.

     Description of drawings

     Fig. 1 is a schematic diagram of a charger of the present invention;

     Fig. 2 is a block diagram of the charging circuit of the charger of the present invention;

     Fig. 3 is the work flowchart of charger of the present invention;

     FIG. 4 is a diagram of the charging circuit in FIG. 2 .

     In the figure, 1, casing; 101, upper casing; 102, lower casing; 2, charging slot; 3, operation panel; 3a, control switch; 4a, red LED; 4b, green LED; 5, charging circuit; 6. Control circuit; 7. Indicating circuit; 8. Temperature detection circuit; 9. Voltage detection circuit; 10. Mode selection circuit; 11. Conversion charging circuit; 110. AC-DC input circuit; 111. DC-DC power supply circuit; 112. DC voltage output circuit; 13. External trigger signal.

     Detailed ways

     The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

     As shown in Figure 1, it is a preferred schematic diagram of the charger of the present invention. The casing 1 is formed by fastening an upper casing 101 and a lower casing 102 to form a whole, and a charging slot 2 for placing a rechargeable battery is provided on the casing 1. The inner cavity formed by the casing 1 includes a charging circuit, and the casing 1 is provided with an operation panel 3 and a display device indicating the charging status, which can be a light-emitting LED or LCD display, and a control switch 3a. Here the display device is a red LED4a and a green LED4b, and the control switch 3a is a button with a backlight.

     The charger has a fast charging mode, or Peak mode, a peak charging mode, and a normal charging mode. In fast charging mode, the charger charges the battery to a relatively full state in a very short time; in normal charging mode, the charger charges normally. The backlight of the control switch 3a is used to indicate whether the battery is in a state where fast charging can be selected, and the backlight flashes to indicate that the battery is being fast charged. When the backlight of the control switch is on, it indicates that the battery meets the conditions for selecting fast charging. After pressing the control switch 3a, the charging enters the fast charging mode, and the backlight flashes. After the fast charging is completed, the backlight of the control switch 3a is always on.

     The red LED4a and green LED4b of the display device are used for error reporting and charging status of normal charging. When the red LED4a is on, it means that there is an abnormal situation in the battery, and this method is used for abnormal situations in both the fast charging mode and the normal charging mode. The green LED4b is used to indicate the charging status of normal charging. When the battery is charging in the normal charging mode, the green LED4b will flicker, and the green LED4b will always be on after the battery is fully charged.

     As shown in Figure 2, the structure of the charger charging circuit 5 of the present invention includes a temperature detection circuit 8 and a voltage detection circuit 9, which monitor the current temperature and voltage of the rechargeable battery in real time, and transmit the monitored values to the control circuit 6; the control circuit 6 receives And process the information of the temperature detection circuit 8, the voltage detection circuit 9 or/and the input information of the external operation panel 3, control the charging mode of the charging circuit 5, and send the current state information to the indicating circuit 7, the indicating circuit 7 can include a display A device for indicating charging status or other information that needs to be displayed.

     The mode selection circuit 10 selects to enter the fast charging mode (abbreviated as Peak mode) or the normal charging mode according to the control signal sent by the control circuit 6, and can switch between the two modes. The conversion charging circuit 11 is connected to the rechargeable battery, including an AC-DC input circuit 110 , a DC-DC power supply circuit 111 and a DC voltage output circuit 112 connected in sequence, and charges the rechargeable battery according to the charging mode issued by the mode selection circuit 10 .

     In one embodiment, the control circuit 6 judges and selects according to the current temperature and voltage value of the rechargeable battery monitored by the temperature detection circuit 8 and the voltage detection circuit 9 in real time, and automatically switches the charging mode. When the battery temperature detected by the temperature detection circuit 8 meets the preset temperature range, and the battery voltage detected by the voltage detection circuit 9 meets the preset voltage range, the control circuit 6 outputs a control signal to the mode selection circuit 10 to charge The mode switches to fast charging mode.

     In another embodiment, the control circuit 6 receives the external trigger signal 13 to switch the charging mode. The external trigger signal 13 can be a signal triggered by a switch, or a trigger signal in the form of light, electricity or sound. In this embodiment, preferably, the control signal is input through the manual control switch 3 a of the operation panel 3 .

     The operation panel 3 is either button-type, touch-type, or a combination of both. It is also possible to integrate the indicating circuit 7 with some or all of the functions of the operation panel 3 . The charging time and charging current can be set through the operation panel 3 .

     As shown in Fig. 2 and Fig. 3, a working flow of the charger of the present invention is illustrated. When the charger detects that a battery is inserted, it first detects whether the temperature and voltage of the battery are allowed by the temperature detection circuit 8 and the voltage detection circuit 9. within the charging range. If the battery needs to be charged, you can choose to enter the fast charging mode (peak mode for short) or the normal charging mode through the mode selection circuit 10, and the fast charging mode switching charging circuit 11 can provide a large current I1 for charging the rechargeable battery, such as 6A. Charge the battery quickly for a short period of time with a large charging current. There are two ways to choose to enter the fast charging mode or the normal charging mode, one is automatic switching, and the other is non-automatic switching, that is, the entry is triggered by an external trigger signal 13 . In this embodiment, only the mode of triggering entry by the external trigger signal 13 is introduced, and the peak mode is entered when the control switch 3a is triggered.

     In Peak mode, set the charging time and charging current. The preset charging current is I1, such as 6A. Compared with the charging current value I2 in normal charging mode, generally, I2 is 1.5A, and I1>I2. Set the charging time as t1, such as 3min. Charging the battery under the condition of this high current can make the energy of the battery charge to a relatively full level, such as 70%, in a preset short period of time, so as to quickly meet the basic needs of users. At the same time, in this mode, the maximum battery temperature allowed by preset charging is T1, such as 40 degrees Celsius, and the maximum battery voltage is V1. When the charging time reaches the set value t1, it exits the Peak mode, or when the detected battery temperature or voltage coefficient is greater than or equal to the preset maximum battery temperature T1, V1, it automatically exits the Peak mode.

     After exiting the Peak mode, if the user does not pull out the battery from the charger, the charging procedure will be transferred to the normal charging mode for charging, and the green LED 4b will flicker. The charging current I2 used in the normal charging mode is smaller than I1, such as 1.5A. In this mode, a series of charging parameters are preset, such as the maximum battery temperature allowed when charging the battery is T2, such as 55 degrees Celsius, the maximum battery voltage is V2, and the battery current is detected. When the detected battery temperature is greater than or equal to the preset maximum temperature T2, or the detected battery voltage is greater than or equal to the preset maximum voltage V2, an error will be reported and the initial program will be returned, and the red LED4a will be on; when the detected battery current is abnormal, such as When it is close to 0, combined with the detection result of the battery voltage, if the detected battery voltage is also greater than or equal to the preset maximum voltage V2, an error will be reported and the initial program will be returned, and the red LED4a will be on.

     Since charging the battery rapidly with a large current in Peak mode may cause damage to the battery or cause dangerous conditions, it is necessary to impose stricter requirements on the various coefficients of the battery in Peak mode. Therefore, the relationship between the above-mentioned Peak mode and the battery charging coefficients in the normal mode is as follows:

     T1<T2;V1<V2;

     If in the normal charging mode, the temperature, current, and voltage coefficient of the battery all meet the set requirements, then the program goes down to the judgment of the charging time.

     When the charging reaches the longest allowable time t2, such as 30min, and the charging current is less than the preset full current I3, it means that the battery is fully charged, and the charging is over, and the green LED4b is always on.

     As shown in Figure 4, port J3 is connected to the positive pole of the battery, port J7 is connected to the negative pole of the battery, port J4 is connected to the port NTC of the battery, and ports J5 and J6 are connected to the ports of a single battery. The MCU micro-control unit chip in the control circuit 6 selects U8. When the battery is inserted into the charger, U8 judges the current temperature and voltage of the battery through the detection ports J4, J5, J6, and J7 in the temperature detection circuit 8 and voltage detection circuit 9. Current information to determine whether to enter fast charging mode to ensure charging safety. When the setting conditions for entering the fast charging mode are met, the fast charging mode can be entered automatically, or can be triggered by an external trigger signal 13. The external trigger signal can be the micro switch SW1 shown in Figure 4, or other light , electricity, sound and other forms of input signal. If it is non-automatic to enter the fast charging mode, when there is no external trigger signal 13 to trigger, U8 controls to charge in the normal charging mode.

     In this embodiment, it is preferred to enter the fast charging mode non-automatically. The process is that when the micro switch SW1 is triggered, that is, the control button 3a on the operation panel 3, U8 detects that the fast charging mode can be entered, and the indicator in the circuit 7 The light-emitting diode D18 is on, indicating that the fast charging mode can be entered, and the backlight of the control button 3a is on. When the micro switch SW1 is pressed, U8 controls the feedback circuit to charge according to the set fast charging current. The light-emitting diode D18 is flickering, indicating that the fast charging mode is in progress, and the backlight of the control button 3a is flickering. In this mode, U8 monitors the voltages of J4, J5, J6, and J7 in real time, and starts timing at the same time, and U8 monitors the temperature of the charger itself through R75, and automatically switches to normal charging mode under abnormal conditions. When the fast charging time reaches the preset charging time, the fast charging is completed, the light-emitting diode D18 is always on, indicating that the fast charging phase is over, and the backlight of the control button 3a is always on. At this time, the user can unplug the battery from the charger for work needs. When the fast charging mode is stopped midway due to reasons such as battery temperature or charger temperature, the light-emitting diode D18 goes out, indicating that the fast charging mode is unavailable, and automatically enters the normal charging mode, indicating that the light-emitting diode D11 in the circuit 7 flickers, making the operation panel 3 The green LED4b of the flashes, indicating that the normal charging mode is in progress. When the battery is fully charged, the light-emitting diode D11 in the indicating circuit 7 is always on, and the green LED4b is always on, indicating that the entire charging process is completed.

     In other embodiments, the current temperature and voltage of the battery can also be detected, and when the setting conditions for entering the fast charging mode are met, the fast charging mode can be automatically entered to realize short-term fast charging of the battery.

     In other implementation manners, other trigger modes other than the micro switch can be used to select the input and enter the fast charging mode.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can also be made. It should also be regarded as the protection scope of the present invention.

Claims (3)

1. A charger, comprising a casing and an operation panel, the casing is provided with a groove that can place a rechargeable battery, the inner cavity formed by the casing has a charging circuit, and the operation panel includes a control switch, and it is characterized in that, The charging circuit has a fast charging mode to charge the rechargeable battery with the first current I1, The charging circuit also has a normal charging mode, charging the rechargeable battery with the second current I2, The charging circuit also includes: a control circuit, a mode selection circuit, a temperature detection circuit, a voltage detection circuit, a conversion charging circuit, a control switch, and an indication circuit. The control circuit controls the switching of the two charging modes through a mode selection circuit, The mode selection circuit selects to enter the corresponding fast charging mode or normal charging mode according to the control signal sent by the control circuit; The conversion charging circuit includes: an AC-DC input circuit, a DC-DC power supply circuit, and a DC voltage output circuit connected in sequence, the conversion charging circuit is connected to the rechargeable battery, and the AC power supply Convert to DC voltage to charge the rechargeable battery; The first current I1 is greater than the second current I2; The fast charging mode presets a first charging time t1, and the normal charging mode presets a second charging time t2; The first charging time t1 is shorter than the second charging time t2; The temperature detection circuit and the voltage detection circuit monitor the current temperature and voltage of the rechargeable battery in real time, and transmit the monitored values to the control circuit, and the control circuit receives and processes the information of the temperature detection circuit and the voltage detection circuit or/and external The input information of the operation panel controls the charging mode of the charging circuit, and transmits the current state information to the indicating circuit; The control circuit judges and selects according to the temperature and voltage of the battery monitored in real time, and then automatically switches the charging mode, or the control circuit switches according to the received external trigger signal; the external trigger signal is determined by the control switch. Triggered signal; the setting conditions that the fast charging mode meets are: the maximum allowable battery temperature is T1, and the maximum battery voltage is V1; the setting conditions that the normal charging mode meets are: the maximum allowable battery temperature is T2, the maximum battery voltage is V2; the maximum battery temperature T1 is less than the maximum battery temperature T2; the maximum battery voltage V1 is less than the maximum battery voltage V2; the fast charging mode presets a first charging time t1, and the normal charging mode presets a The second charging time t2, the first charging time t1 is less than the second charging time t2; in the normal charging mode, the control circuit monitors the temperature and voltage of the battery in real time if it meets the requirements of the fast charging mode The setting condition is automatically switched to the fast charging mode; the control circuit is when the charging time of the fast charging mode reaches the first charging time t1, or the detected battery temperature or voltage is greater than or equal to the preset maximum battery temperature T1, at the maximum battery voltage V1, automatically exit the fast charging mode, and automatically transfer to the normal charging mode when the battery is not pulled out from the charger, and the control circuit is in the normal charging mode When it is detected that the temperature of the battery is greater than or equal to the maximum battery temperature T2 or the detected voltage of the battery is greater than or equal to the maximum battery voltage V2, the normal charging mode is exited, and the control circuit is in the normal charging mode and The charging time of the normal charging mode is judged when the setting condition of the normal charging mode is met, and the charging is stopped if it is greater than or equal to the second charging time t2. 2. The charger according to claim 1, wherein the indicating circuit is used to indicate the charging state, the state of the charging mode, and the abnormal state. 3. The charger according to claim 1, wherein the control switch is a button type.

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