CN204179727U - A kind of power tool battery bag and charge-discharge system thereof - Google Patents

Abstract

The utility model discloses an electric tool battery pack and a charging and discharging system thereof. There is a control unit in the battery pack of the electric tool, which can collect the cell voltage and temperature signal of the battery unit, and send the collected signal to the microprocessor MCU of the charger and the electric tool, and the microprocessor of the charger and the electric tool The controller MCU processes and calculates the received data to control the charging and discharging process of the battery pack. In this way, the accuracy of charging and discharging control of the battery pack can be improved, and the performance of the battery pack can be improved.

Description

An electric tool battery pack and its charging and discharging system

【Technical field】

The utility model relates to a battery pack of an electric tool, in particular to a charging and discharging control system of the battery pack.

【Background technique】

Generally known battery packs for electric tools, as shown in Figure 17, usually include a plurality of battery cells connected in series, a battery pack ID, a temperature sensor, and positive and negative terminals, where the battery pack ID can include, for example, the model, version The temperature sensor can be a negative temperature coefficient (NTC) resistor, and the charging and discharging detection and control of the battery pack are completely controlled by the charger and the tool alone; however, with the DC power tool With the increase of power, there are more and more battery cells in the battery pack of electric tools. Using the existing battery pack charging and discharging mode, the charger or tool cannot sample the voltage of multiple unit cells in the battery unit. The total voltage sampled from the charger or the tool will have a large error, so that the charging and discharging of the battery unit cannot be accurately controlled, resulting in a decrease in the performance of the battery pack.

【Content of utility model】

In order to solve the above problems, the utility model proposes a new electric tool battery pack charging and discharging control system and method, which can accurately detect and control the charging and discharging functions of the battery pack, and improve the performance of the battery pack.

The utility model provides the following technical solutions: a battery pack for an electric tool, which is detachably connected to a charger, comprising: a housing, a battery unit composed of at least two lithium batteries connected in series, a resistor connected to the positive pole of the lithium battery, a temperature The sensor is used to detect the temperature of the battery unit, and also includes a control unit, which is used to collect the voltage signal of the battery unit of the battery unit and the temperature signal of the temperature sensor;

A further improvement solution includes: the temperature sensor is a negative temperature coefficient (NTC) resistor.

Further improvements include: the control unit includes a detection unit and a microprocessor (MCU), the detection unit is used to detect the cell voltage and temperature of the battery unit, and the battery pack microprocessor (MCU) is used to control the detection unit, and store the battery pack ID data.

Further improvement schemes include: the control unit sends the collected data from the battery pack microprocessor (MCU) to the charging microprocessor (MCU) on the charger side, and the charger side microprocessor (MCU) processes the above data. The microprocessor on the charger side determines that the detected cell voltages are not consistent, and then performs an equalization function. The microprocessor (MCU) on the charger side sends an equalization control command to the microprocessor (MCU) on the battery pack side through the communication port, and the microprocessor (MCU) on the battery pack side controls the detection unit to execute the equalization control command to discharge the unit cells until The cell voltages are substantially the same.

The further improvement scheme has: a charging method for a battery pack, comprising: a charger microprocessor (MCU) determines whether to be electrically connected with the battery pack to be charged through a communication port; the microprocessor (MCU) of the charger is based on the battery pack The voltage and temperature data detected by the control unit of the battery pack are used to execute the predetermined charging mode; the battery pack control unit automatically periodically sends the unit battery voltage and temperature data to the charger MCU every 10ms to 1s.

The utility model provides another technical solution: an electric tool battery pack, which is detachably connected to a charger, the charger has a charger microprocessor (MCU1) and a signal transmission terminal, and the electric tool battery pack includes: Housing, a battery unit composed of at least two lithium cells in series, a resistor connected to the positive pole of the lithium cell, a temperature sensor, used to detect the temperature of the battery cell, and a signal transmission terminal, which is electrically connected to the signal transmission terminal of the charger Sexual connection; the electric tool battery pack also includes a control unit, when the control unit of the electric tool battery pack receives the microprocessor demand instruction of the above-mentioned charger; the control unit of the electric tool will collect the unit battery of the battery unit Voltage and temperature signals, and the collected signals are sent to the microprocessor of the charger at regular intervals through the signal transmission terminal.

Since the battery pack is equipped with a control unit, the charger can monitor the cell voltage and temperature signal of the battery cell in real time during the charging process. When the cell voltage is inconsistent, the control unit can adjust the cell voltage to make the cell voltage substantially Since the temperature of the battery cells in the battery pack and the voltage signal of the unit cells can be monitored in real time during the charging process, the charging performance can be made more reliable. At the same time, during the discharge process of the battery pack, the micro The processor (MCU) can also obtain the temperature and unit cell voltage signals of the battery cells in the battery pack in real time, and can accurately control the discharge process of the battery pack, thereby improving the performance of the battery pack.

【Description of drawings】

Figure 1: Schematic diagram of the battery pack of the present invention.

Figure 2: A schematic diagram of the charger of the present invention.

Figure 3: Schematic diagram of the battery pack and electric tool of the present invention.

Figure 4: Circuit block diagram of the rechargeable battery pack of the present invention.

Fig. 5: The circuit block diagram of the charger of the present utility model.

Fig. 6: Circuit block diagram of the electric tool of the present utility model.

Fig. 7: The charging circuit diagram of the battery pack of the first embodiment of the present invention.

Fig. 8: The discharge circuit diagram of the battery pack of the first embodiment of the present invention.

Fig. 9: The flow chart of charging the battery pack in the first embodiment of the present invention.

Fig. 10: The flow chart of battery pack discharge in the first embodiment of the present invention.

Fig. 11: The charging circuit diagram of the battery pack of the second embodiment of the present invention.

Fig. 12: The discharge circuit diagram of the battery pack of the second embodiment of the present invention.

Fig. 13: The charging circuit diagram of the battery pack of the third embodiment of the present invention.

Fig. 14: The discharge circuit diagram of the battery pack of the third embodiment of the present invention.

Fig. 15: The charging flow chart of the battery pack according to the third embodiment of the present invention.

Fig. 16: The battery pack discharge flow chart of the third embodiment of the present invention.

Figure 17: Block diagram of a prior art battery pack.

【Detailed ways】

Below in conjunction with accompanying drawing, the embodiment of the utility model is described in detail, wherein Fig. 1 to Fig. 3 are the electric tool battery pack 2 used in the utility model respectively, and the charger 1 and the electric tool 3 paired with it, the battery pack 2 It has at least three terminals, of which a pair of terminals are electrical terminals connected to the charger, and the other or more terminals are signal transmission terminals (of course also called COM terminals), which are used to make signals with the charger 1 or the electric tool 3 Transmission; In this embodiment, the electric tool 3 mainly shows an impact drill, of course, the electric tool battery pack can also be used in other products, such as angle grinders, lawn mowers, etc.

In the following embodiments, a battery unit composed of five lithium batteries connected in series is taken as an example.

Implementation mode one:

As shown in Figure 4, it is the circuit block diagram of the utility model battery pack, and this battery pack 2 is a lithium battery pack, and it comprises the battery unit that is formed by the series connection of many lithium cells; A temperature sensor, is used to detect battery pack temperature ; The control unit connected with the battery unit is used to detect and send the voltage and temperature signal of the unit battery, and can control the discharge of the unit battery.

As shown in Figure 5, it is the circuit block diagram of the charger of the present utility model, and it comprises a microprocessor (MCU1) that is connected with the control unit of battery pack 2, is used for receiving the cell voltage that the control unit of battery pack 2 gathers , temperature data to control the charging circuit, adjust the charging current and voltage, and issue control instructions to the control unit of the battery pack 2; it also includes an AC-DC (AC-DC) conversion circuit.

As shown in FIG. 6 , it is a circuit block diagram of the electric tool of the present invention. It includes a microprocessor (MCU2), which is connected to the microprocessor (MCU3) of the battery pack 2, and is used to receive the unit cell voltage and temperature data of the control unit of the battery pack 2 to control the switching circuit of the tool and adjust the power tool 3 Current or output power of the motor.

As shown in FIG. 7 , it is a charging circuit diagram of the battery pack 2 of the present invention. The positive and negative poles of the battery unit are connected to the positive and negative poles of the charger 1; the control unit includes a detection unit and a microprocessor MCU3, and the battery ID information is stored in the microprocessor MCU3. One end of multiple resistors R1, R2, R3, R4, R5 is respectively connected to the positive poles of the unit cells cell1, cell2, cell3, cell4, cell5, and the other end is connected to the detection unit for detecting and adjusting the voltage of the unit cell, and the other end is connected to the detection unit The connected negative temperature coefficient (NTC) resistor is used to detect the temperature of the battery unit, and the microprocessor MCU3 is connected to the detection unit, and communicates with the microprocessor of the charger 1 through the communication terminal COM (also called the signal transmission terminal, the same as below) The MCU1 of the charger performs data transmission, and the microprocessor MCU1 of the charger 1 receives the ID of the battery pack, the voltage of the unit battery, and the temperature data, and performs processing and calculation on the received data, thereby controlling the charging circuit and implementing charging.

The specific charging process is shown in Figure 9. When the battery pack 2 is not inserted into the charger 1, the charger communication terminal COM is at a high level, and the charger 1 is always in a standby state. When the battery pack 2 is inserted into the charger 1, the charger The COM level of the communication terminal is pulled down, and it is recognized that a battery pack 2 is inserted, and the charger 1 sends a charging start command to the battery pack 2, and the battery pack 2 is activated, and its microprocessor MCU3 receives the charging start command, and controls The detection unit detects the unit cell voltage and temperature signal of the battery unit, and sends the voltage, temperature and battery pack ID data to the microprocessor MCU1 of the charger 1, if the microprocessor MCU1 of the charger 1 determines that the battery pack 2 If the incoming ID signal can be identified, it is further judged whether the cell voltage and temperature data are normal, and if it shows that the battery pack 2 is not fully charged, then the battery pack 2 is charged. The communication method during the charging process is: the microprocessor MCU3 in the battery pack controls the detection unit to sample the voltage and temperature of the battery cells in the battery pack in real time, and periodically transmits the voltage, temperature and ID signal of the unit cells every 10ms-1s. Actively send to the microprocessor MCU1 of the charger 1 through the communication terminal COM, and the cycle is preferably 100ms. The microprocessor MCU3 of the charger 1 processes the received data. Taking the 18650 lithium battery as an example, if the voltage of the multi-unit battery The minimum value is lower than 2.5V, and the microprocessor MCU1 of the charger 1 controls the charging circuit to precharge the battery pack 2; if the minimum voltage of the unit battery is greater than or equal to 2.5V and less than 4.18V, constant current charging is performed; if the voltage of the unit battery When the minimum value is greater than or equal to 4.18V, constant voltage charging is performed; during constant voltage charging, if the charging current is less than 0.1C, it means that the charging is completed. If the battery pack 2 cannot be matched or the battery pack 2 is fully charged, the charging will end.

After the battery pack is fully charged, if the microprocessor MCU1 of the charger 1 determines that the received voltages of the multiple unit cells cell1, cell2, cell3, cell4, and cell5 are inconsistent, and the difference between the maximum value and the minimum value is greater than the preset value, then Perform equalization function, the preset value is greater than or equal to 50mV. The microprocessor MCU1 on the charger 1 side sends an equalization control command to the microprocessor MCU3 on the battery pack 2 side through the communication terminal COM, and the microprocessor MCU3 on the battery pack 2 side controls the detection unit to execute the equalization control command to discharge the unit cells, so that all The cell voltages are substantially the same. For example: if it is detected that the voltage of cell3 is higher than the voltage of other cells and the difference is greater than the preset value, turn on resistor R3 and let cell3 discharge through resistor R3 alone until the voltage of cell3 drops to the same voltage as other cells.

As shown in Fig. 8 and Fig. 10, it is the discharge circuit and flowchart of the battery pack 2 of the present invention. The positive and negative terminals of the battery unit are connected to the positive and negative terminals of the electric tool 3; the microprocessor MCU3 of the battery pack 2 is connected to the microprocessor MCU2 of the electric tool 3 through the communication terminal COM. The specific discharge process of the battery pack 2 is as follows: the microprocessor MCU2 of the electric tool 3 detects that the tool switch is triggered, and then notifies the microprocessor MCU3 of the battery pack 2 to send the cell voltage, temperature and battery ID data of the battery pack 2. If the data received by the tool 3 is normal, the switch circuit of the tool is allowed to be turned on, and the battery pack 2 starts to discharge. The microprocessor MCU3 of the battery pack 2 actively sends the unit battery voltage, temperature and battery pack ID data to the microprocessor MCU2 of the electric tool 3 periodically at intervals of 100ms-1s, and the cycle is preferably 100ms. The microprocessor MCU2 of the electric tool 3 controls the discharge current and voltage according to the received data. If the cell voltage reaches the cut-off voltage or the discharge current exceeds the maximum allowable discharge current of the battery pack, the discharge ends.

Implementation mode two:

As shown in Fig. 11 and Fig. 12, it is the charging and discharging circuit diagram of the second embodiment of the utility model, the negative temperature coefficient (NTC) resistor is connected with the reference voltage Vcc after being connected in series with a voltage dividing resistor R, and the sampling data is directly sent to Microprocessor MCU3. Embodiment 2 is basically similar to Embodiment 1. For the charging and discharging flowchart, please refer to the charging and discharging flowchart of Embodiment 1. The main difference is that the communication modes between the battery pack 2 and the charger 1 or the electric tool 3 are different. , that is: the communication mode during the charging process: the microprocessor MCU1 of the charger 1 sends a data sampling command or data request command to the microprocessor MCU3 of the battery pack 2 through the communication terminal COM, and the microprocessor MCU3 of the battery pack 2 controls the sampling unit The corresponding data is collected and processed, and then the processing result is sent to the microprocessor MCU1 of the charger 1 through the communication terminal COM. For example: if the microprocessor MCU1 of the charger 1 needs the voltage data of a single battery, the microprocessor MCU3 of the battery pack 2 will compare the collected voltage signals of the five batteries, select the maximum value, and send it to Microprocessor MCU1 of charger 1. If the microprocessor MCU1 of the charger 1 needs the temperature data signal of the battery unit, the microprocessor MCU3 of the battery pack 2 collects the temperature data and compares the temperature data with the preset value, and sends the comparison result to the charger 1 Microprocessor MCU1.

The communication mode in the discharging process is the same as that in the charging process. The duplex communication is realized between the battery pack 2 and the electric tool 3 through the communication terminal COM, and the microprocessor MCU3 of the battery pack 2 should correspond to the microprocessor of the electric tool 3 The request command of MCU2 collects and sends relevant data results.

Implementation mode three:

The difference from Embodiment 1 is that, as shown in FIGS. 13 to 16 , the control unit in the battery pack 2 only includes a detection unit and does not have a microprocessor MCU3. Therefore, the communication mode during the charging process of the battery pack 2 is as follows: The microprocessor MCU1 of the charger 1 sends a data request command through the communication terminal COM1, and the detection unit in the battery pack 2 will collect the data required by the charger 1, such as the unit battery voltage, temperature, and battery pack ID data, and send the data to the charger. 1 The required data is sent to the charger 1 through the communication terminal COM2. The communication method during the discharge process of the battery pack 2 is: the microprocessor MCU2 of the electric tool 3 sends a data request command, and the detection unit in the battery pack 2 collects the data required by the electric tool 3 and sends it to the electric tool 3 .

The above embodiments do not limit the utility model in any form, and all technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the utility model.

Claims (8)

1. a power tool battery bag, is removably connected with charger, comprising:

Housing,

The battery unit be at least composed in series by two lithium element cells,

The resistance be connected with lithium element cell positive pole,

Temperature sensor, for detecting the temperature of battery unit,

At least three terminals, wherein pair of terminal is the both positive and negative polarity be connected with charger, and at least another terminal is the Signal transmissions terminal be electrically connected with charger;

It is characterized in that: described power tool battery bag also comprises a control unit, for gathering voltage and the temperature signal of the element cell of battery unit, and by the signal that collects by the timed sending of Signal transmissions terminal intervals to described charger.

2. power tool battery bag according to claim 1, is characterized in that: described temperature sensor is a negative temperature coefficient (NTC) resistance.

3. power tool battery bag according to claim 2, it is characterized in that: described control unit comprises a detecting unit and a microprocessor (MCU3), detecting unit is for detecting cell voltage and the temperature of battery unit, power brick microprocessor (MCU3) is for controlling described detecting unit, and storage battery bag ID data.

4. power tool battery bag according to claim 3, it is characterized in that: if the cell voltage that described detecting unit detects is inconsistent, then by discharging to corresponding element cell to the resistance that element cell connects, make cell voltage identical in fact.

5., for a charge-discharge system for power tool battery bag in claim 1, comprising:

Charger has charger microprocessor (MCU1);

This charger microprocessor (MCU1) determines whether to realize being electrically connected with power tool battery bag to be charged by communication port;

It is characterized in that: described power tool battery bag control unit is automatically periodically to charger microprocessor (MCU1) transmitting element cell voltage and temperature data signal; Voltage, temperature data signal that the microprocessor (MCU1) of charger detects based on the control unit of power brick, perform predetermined charge mode.

6. for a charge-discharge system for power tool battery bag in claim 5, it is characterized in that: described power tool battery bag control unit is every the periodic transmission of data signals of 10ms to 1s.

7. the charge-discharge system for power tool battery bag in claim 6, it is characterized in that: if the cell voltage that described detecting unit detects is inconsistent, charger microprocessor sends corresponding data, the control unit of notice power tool battery bag discharges to corresponding element cell, makes cell voltage identical in fact.

8. a power tool battery bag, is removably connected with charger, and this charger has charger microprocessor (MCU1) and Signal transmissions terminal, and described power tool battery handbag is drawn together: housing,

The battery unit be at least composed in series by two lithium element cells,

The resistance be connected with lithium element cell positive pole,

Temperature sensor, for detecting the temperature of battery unit,

Signal transmissions terminal is mutually electrically connected with the Signal transmissions terminal of charger;

It is characterized in that: described power tool battery bag also comprises a control unit, when the control unit of this power tool battery bag receives the microprocessor requirement command of above-mentioned charger; The control unit of electric tool will gather voltage and the temperature signal of the element cell of battery unit, and by the signal that collects by the timed sending of Signal transmissions terminal intervals to the microprocessor of described charger.