WO2018107385A1

WO2018107385A1 - Charger capable of testing battery parameters

Info

Publication number: WO2018107385A1
Application number: PCT/CN2016/109893
Authority: WO
Inventors: 邹伟华; 罗华兰
Original assignee: 深圳市伟义兄弟进出口有限公司
Priority date: 2016-12-14
Filing date: 2016-12-14
Publication date: 2018-06-21

Abstract

Provided is a charger capable of testing battery parameters, comprising a meter probe (1), comprising two meter probe bodies (10) and a male/female port (20) that has an interface comprising at least four pins, each of the meter probe bodies (10) comprising a probe (11) and two insulated conductors (13), a front end of the probe (11) being used to contact an object to be tested, a rear end of the probe (11) being electrically connected to one end of the two conductors (13), and the other end of the two conductors (13) being electrically connected to one pin of the male/female port (20), respectively; a charger main body (2), used to charge a battery and provided with a female/male port (21) matching the male/female port (20) of the interface of the meter probe (1); and a four-wire test circuit, provided inside the charger main body (2) and electrically connected to the female/male port (21) of the charger main body (2) for performing parameter testing on a battery to be tested in cooperation with the meter probe (1). The battery parameters obtained from testing by the charger, such as internal resistance and/or voltage, are highly accurate and have reference value.

Description

Manual Title: A Charger That Can Test Battery Parameters

The present invention relates to the field of chargers.

BACKGROUND OF THE INVENTION

[0003] A charger is a device that charges a rechargeable battery after an external power source. At present, some chargers are equipped with a function of testing the internal resistance of the battery, and the implementation thereof is as follows: a positive electrode and a negative electrode for connecting the battery to charge the battery through the charger itself, and connecting the battery to the built-in test internal resistance circuit of the charger In order to test the internal resistance of the battery. The internal resistance of the battery tested by this charger is very inaccurate, because the test is actually the sum of the internal resistance of the battery and the resistance of the positive and negative electrodes of the charger; and because the internal resistance of the battery is small, it is generally European grade, and the impedance of the positive and negative poles of the charger far exceeds this value, so this makes the internal resistance of the battery obtained by the charger test has no reference significance.

SUMMARY OF THE INVENTION

According to a first aspect, an embodiment provides a charger that can test battery parameters, and the tested battery parameters, such as internal resistance and/or voltage, are accurate and have reference significance. The charger that can test battery parameters, including:

[0006] a test pen, the test pen includes two pen body and a male/female port including at least four pins; wherein each of the pen body includes a probe and two insulated wires, the probe The front end is for contacting with the body to be tested, the rear end of the probe is electrically connected to one end of the two wires, and the other ends of the two wires are respectively electrically connected to one pin of the male/female port;

[0007] the charger body is configured to charge the battery after being connected to the external power source; the charger body is provided with a female port/male port matching the male/female port of the interface of the test chart;

[0008] A four-wire test circuit is disposed in the charger body and electrically connected to the female/public port of the charger body for performing parameter test on the battery to be tested.

[0009] According to the above-mentioned implementation of the battery parameter test charger, due to the introduction of the four-wire test lead and four-wire test circuit, eliminating the influence of the resistance of the wire connected to the battery to be tested on the battery internal resistance test, the test result Precise and reliable; and because the charger body and the test leads are pluggable through the interface, The charger has a simple structure and is convenient to use. When an internal resistance test is required, the male/female port of the test pen is inserted into the female/male port of the charger body, and when the internal resistance test is not required, the charger The test leads are unplugged from the interface.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1(a) is a schematic diagram of a two-wire test resistor; FIG. 1(b) is a schematic diagram of a four-wire test resistor; [0012] FIG. 2 is a charger using a two-wire test resistor Schematic diagram

_{3 is} a schematic structural diagram of a test chart according to an embodiment of the present application;

4 is a schematic structural view of a probe of a test chart according to an embodiment of the present application;

[0015] FIG. 5 is another schematic structural diagram of a probe of a test chart according to an embodiment of the present application;

6 is a schematic exploded view of a test chart according to an embodiment of the present application;

7 is a perspective view of a test chart according to an embodiment of the present application;

8 is a schematic structural view of a charger capable of testing battery parameters after removing a test lead according to an embodiment of the present application;

9 is a schematic structural diagram of a charger capable of testing battery parameters according to an embodiment of the present application;

10 is a diagram of a four-wire test circuit of a charger that can test battery parameters according to an embodiment of the present application.

DETAILED DESCRIPTION

[0022] For a better understanding of the present application, a two-wire test resistance scheme and a four-wire test resistor scheme are first described.

[0023] Please refer to FIG. 1(a), which is a technical solution for testing the resistance of the two-wire system. The current I is emitted through a rated current source, and the voltage drop U on the resistor R to be tested is tested by a voltmeter, so that the resistance of the battery R can be obtained as U/I. However, in fact, the wires are also electrically resistive. As shown in the figure, the wires connected to the two ends of the resistor R are respectively rl and r2, so the voltage drop U obtained by the test is substantially the resistance R, the wire rl and the wire. The common voltage drop of r2, so the resistance obtained by U/I calculation is essentially (R+rl+r2). When measuring the resistance 很小 with small resistance, (R ₊ rl ₊ r2) is not equal to R, This makes the resistance obtained by the test inaccurate and unreliable. In other words, the technical solution of the two-wire test resistor, when testing the resistance 很小 with a small resistance value, the wire used to connect the resistance to be tested will affect the test result. The test results are inaccurate, unreliable and have no reference significance. [0024] Please refer to FIG. 1(b), which is a technical solution for testing a resistance of a four-wire system. The current I is emitted through a rated current source, and the voltage U on the circuit under test R is tested by a voltmeter, but the rated current source and the voltmeter are not connected to the resistor R through a common wire, but the rated current source passes through the wire rl. And r2 are respectively connected to the two ends of the resistor R, and the voltmeter is connected to both ends of the resistor R through the wires r3 and r4. Since the input resistance of the voltmeter is large, substantially no current flows, so the measured voltage drop U is The voltage drop of the resistor R, and the current flowing through the resistor R is again I, so the resistance value calculated by U/I is the resistance of the resistor R. In other words, the technical solution of the four-wire test resistor is used for The wire connecting the resistor to be tested does not affect the test results, so the results of such tests are accurate and reliable.

[0025] The positive electrode and the negative electrode of the charger are connected to the battery to be tested, and the internal resistance test is performed on the battery. The principle is the technical solution of the two-wire test resistor shown in FIG. 1). The circuit diagram is explained.

[0026] Please refer to FIG. 2, which is a practical example of a charger using a two-wire test resistor scheme.

[0027] In the figure, BT1 represents a battery to be tested, and the battery to be tested is electrically connected to the test circuit of FIG. 2 by the positive electrode tab BT1+ and the negative electrode tab BT1- for charging by the charger.

[0028] It can be seen from FIG. 1 that the test circuit is based on a rated current source, so firstly, the constant current charging principle and the constant current discharge principle of the test circuit of FIG. 2 are explained, and then the internal resistance method of the charging test based on constant current charging is described. Internal resistance method for discharge test based on constant current discharge.

[0029] Constant current charging principle: When the pulse width modulation signal PWM1 is high level, transistors Q2, Q7 and Q4 are turned on.

The +12V supply current is stored in the inductor L1 through the transistor Q4, and the inductor current of the inductor L1 gradually rises, and returns to the power supply terminal through the diode D2, the resistor R7, the battery BT1 and the transistor Q6. When the PWM signal PWM1 is low level, transistor Q2 is turned off, transistor Q1 is turned on, transistor Q4 is turned off, and the inductor voltage of inductor L1 is left negative right positive. The energy stored by inductor L1 is diode D2 and resistor. R7, battery BT1, transistor Q6 and diode D1 form a loop. The Heyi MCU detects the voltage of the VI terminal and the V2 terminal, and calculates a real current il through (V1-V2) / R7; compares the real current il with a preset current II, when the detected current il ratio The preset current II is small, and the positive duty ratio of the pulse width modulation signal PWM1 is adjusted to increase the positive duty ratio; when the detected current il is greater than the preset current II, the pulse width modulation signal PW Ml is adjusted. Positive duty cycle, so that its positive duty cycle is reduced; thus continuously adjusting the positive duty cycle of the pulse width modulation signal PWM1, so that (V1-V2) / R7 can maintain the magnitude of the preset current II, that is, keep the current constant Real Now constant current charging.

[0030] Constant current discharge principle: When the pulse width modulation signal PWM2 is low level, the external power supply stops supplying power. The current of the battery BT1 starts from the positive pole of the battery and returns to the negative pole of the battery via resistor R7, resistor R6, transistor Q5 and transistor Q6. The MCU detects the voltages of the VI terminal and the V2 terminal, and calculates a real current i2 through (V2-V1) / R7; compares the real current i2 with a preset current 12, when the detected current i2 is preset The current is 12 hours, the positive duty ratio of the pulse width modulation signal PWM2 is adjusted to increase the positive duty ratio; when the detected current i2 is greater than the preset current 12, the positive duty of the pulse width modulation signal PWM2 is adjusted. Ratio, so that its positive duty cycle is reduced; thus continuously adjusting the positive duty cycle of the pulse width modulation signal PWM2, so that (V2-V1) / R7 can be kept at the preset current 12, that is, the current is kept constant, realizing Constant current discharge.

[0031] Charging test internal resistance method based on constant current charging: When the battery is placed in the charging tank of the charger, the charger detects that there is a battery 吋, and the pulse width modulation signals PWM1 and PWM2 are both set to a low level, and the battery is in the absence of The load is the no-load state, and the battery voltage V2 read by the 吋MCU is recorded as V2a; the pulse width modulation signal PWM1 is set to the output duty ratio state, so that the battery is in the constant current charging state, and the MCU reads the battery constant current charging state. The voltage at the V2 terminal is recorded as V2b. By calculating (V2b-V2a) /II, the internal resistance of the state of charge of the battery can be obtained.

[0032] Discharge test internal resistance method based on constant current discharge: When the battery is placed in the charging tank of the charger, the charger detects that there is a battery 吋, and the pulse width modulation signals PWM1 and PWM2 are both set to a low level, and the battery is in the absence of The load is the no-load state. In this case, the MCU read battery voltage V2 is recorded as the value of V2c. The pulse width modulation signal PWM2 is set to the output duty cycle state, so that the battery is in a constant current discharge state, and the voltage of V2 of the MCU reading the battery constant current discharge state is recorded as V2d; by calculating (V2c-V2d) 112, it can be obtained The internal resistance of the discharge state of the battery.

[0033] The above scheme for detecting the internal resistance of current charging or discharging has a large uncontrollable error, and the consistency is not good, and as the number of uses increases, the contact faces of the connectors are also worn, and the contact resistance thereof increases. Big. In addition, the internal resistance of the battery is mostly below 100 milliohms, some as low as a few milliohms, and the contact resistance of each connector has far exceeded this value. Therefore, the test value is not reliable and has no reference value.

[0034] The present application will be further described in detail below with reference to the accompanying drawings.

[0035]

[0036] Embodiment 1 [0037] This embodiment discloses a test lead pen, which is a four-wire test lead pen. The traditional four-wire tab generally includes four discrete sub-pens, two of which are used to contact the resistor to be tested to form a voltage loop for voltage testing, and the other two sub-tables are used to contact the resistor to be tested to form a current loop. , conduct a current test. The test pen proposed in this embodiment is an integrated, miniaturized and versatile four-wire stylus. Specifically, referring to FIG. 3, the test stylus of the embodiment includes two stylus body 10 and at least four The sub-port 20 of the interface of the pin is the male port or the female port of the interface. In an embodiment, the interface is a U SB interface, a mini-USB interface or a USB Type-C interface.

[0038] Each of the pen body 10 includes a probe 11 and two insulated wires 13 . The front end of the probe 11 is for contacting the body to be tested, and the rear end of the probe is electrically connected to one end of the two wires 13 . The other ends of the two wires 13 are electrically connected to one pin of the sub-port 20, respectively, so that the two wires 13 occupy the two pins of the sub-port 20 to be electrically connected, that is, each of the pen body 10 occupies two of the sub-ports 20 One pin, then the two pen body 10 occupies the four pins of the sub-port 20 in total. It is possible to use the USB interface as an example, and the four pins VBUS, D+, D- and VSS in the USB interface can be occupied as the above. The four pins. In one embodiment, two of the wires 13 insulated from each other in each of the pen body 10 can be wrapped with an insulating sleeve.

In an embodiment, the outer surface of the probe 11 is plated with gold, which can effectively reduce the contact resistance and has the advantages of preventing oxidation and the like.

[0040] In an embodiment, as shown in FIG. 4, the front end of the probe 11 is planar, and a plurality of protrusions 111 are disposed thereon, and the plurality of protrusions 111 are used for contacting the body to be tested, due to the probe 11 The use of multi-point contact can effectively prevent contact failure, especially when the body to be tested is a battery pack, which can prevent contact failure caused by partial oxidation or unevenness of the positive electrode cap of the battery.

[0041] In an embodiment, in FIG. 5, the probe 11 includes a probe sleeve 113 and an inner needle 115 movably disposed in the probe sleeve 113 with respect to the probe sleeve 113; the probe sleeve 113 includes a limiting portion at the rear end. 113a and the front cover portion 113b, the stopper portion 113a and the cover portion 113b are connected by an elastic member 113c. Further, referring to FIG. 6 and FIG. 7 , the pen body 10 further includes a casing 15 disposed outside the two wires of the pen body 10 , and one end of the casing 15 abuts against the limiting portion 113 a of the probe sleeve 113 . Using 吋, since the probe 11 is in elastic contact, this facilitates the effective contact between the probe 11 and the positive and negative electrodes of the battery to be tested, saving effort, and no contact failure due to hand shake or the like during the test. In an embodiment, the outer casing 15 comprises a hard outer casing 1 5a and a soft outer casing 15b provided on the outer surface of the hard outer casing 15a.

[0042] The test lead provided in this embodiment includes two watch pen body 10, and each of the pen body 10 includes a probe 11 and two insulated wires 13 for use. For each pen body 10, it can be One wire 13 is used as the current line, and the other wire 13 is used as the voltage line for the four-wire measurement, eliminating the contact resistance and the internal resistance of the test line; in addition, since each of the pen body 10 is integrated with two insulation settings The wires 13 and the wires 13 of the two pen body 10 are electrically connected to the male/female port of the interface including at least four pins, so that the test leads are integrated, miniaturized, and only one interface is used, which is convenient to operate.

[0043]

[0044] Embodiment 2

[0045] This embodiment discloses a charger that can test battery parameters. In an embodiment, referring to FIG. 8 and FIG. 9, the charger for testing battery parameters includes a test lead 1, a charger body 2, and a four-wire test circuit (not shown). In an embodiment, The display unit 3 can be included.

The pen 1 is a four-line pen. In an embodiment, the pen 1 can be a pen in the first embodiment. The following is an example of a pen in the first embodiment.

[0047] The charger body 2 is used to charge the battery after being connected to an external power source. The charger body 2 is provided with another sub-port 21 matching the sub-port 20 of the interface of the test pen 1, when the sub-port 20 of the test pen 1 is a male port, and the sub-port 21 of the charger body 2 is a matching female port. When the sub-port 20 of the pen 1 is a female port, the sub-port 21 of the charger body 2 is a matching male port.

[0048] The four-wire test circuit is disposed in the charger body 2, and the four-wire test circuit is electrically connected to the female/public port 21 of the charger body 2, and is used for performing parameter test on the test battery with the test pen 1 In one embodiment, the parameter includes an internal resistance and/or a voltage.

[0049] The display unit 3 is disposed on the charger body 2 for displaying parameters obtained after the test of the battery to be tested by the four-wire test circuit.

[0050] The four-wire test circuit can be a four-wire DC discharge internal resistance test circuit or a four-wire AC voltage drop internal resistance test circuit, please refer to FIG. 10, and a four-wire DC discharge internal resistance test is given below. The actual circuit schematic of the circuit.

[0051] In the figure, CON4 is a female/public port 21 disposed on the charger body 2, wherein the first and fourth pins respectively receive the positive and negative electrodes of the battery through the test pen 1 to form a path of constant current discharge of the battery; 1 point through the test leads Do not receive the positive and negative electrodes of the battery to form a path to directly detect the battery voltage. The functions of diodes D5 and D4 mainly prevent the battery to be tested from exceeding 5V from being connected, and burn out the AD port of the single-chip microcomputer (not shown) in the four-wire test circuit, which acts as an overvoltage protection. When the test pen 1 does not touch the positive and negative electrodes of the battery to be tested, the voltage at RV1 is about +5V, and the value detected by the resistor R9, the diode D3 and the resistor R21 is much higher than the voltage of the single cell, so the MCU determines that There is no state of battery access to be tested. When the test lead 1 contacts the positive and negative poles of the battery to be tested, the value of RV1 will be lower than 5V, and the single chip judges that the battery to be tested is connected. In the figure, the resistor Rl l, the resistor R22, the transistor Q3, the resistor R12, the transistor Q9, the resistor R23 and the transistor Q11 constitute a reverse connection protection circuit of the battery to be tested, preventing the battery to be tested from being reversely connected, preventing the positive and negative electrodes of the battery to be tested from passing through the transistor Q8 and Resistor R28 directly forms the loop and burns the circuit. Resistors R26 and R27 form the voltage reference terminal of the constant current circuit. The resistor R24, the transistor Q8, the resistor R28 and the resistor R25 constitute a negative feedback circuit of the operational amplifier. In another embodiment, a capacitor C6 can be added as shown in FIG. 10 such that the resistor R24, the transistor Q8, the resistor R28, and the resistor R25 And C6 constitute the negative feedback circuit of the op amp. U1B is a high precision op amp. Resistor R29, transistor Q10 and resistor R14 form an enable circuit for controlling the discharge of the battery to be tested. The resistors R16, R17, R18, Rl 9 and the operational amplifier U1A form a differential amplifier circuit of the operational amplifier, which can accurately detect the voltage difference between the positive and negative terminals of the battery to be tested. When the MCU detects that the battery to be tested is connected, the P4.0 port of the MCU outputs a low level, and the transistor Q10 turns on. The negative terminal voltage of the operational amplifier U1B is higher than the positive terminal, the output is zero level, and the transistor Q8 is turned off. The battery is in no-load state. The voltage value of RV2 is detected as: RV2a; The MCU sets P4. 0 to high level, transistor Q10 turns off, and operational amplifier U1B is in normal constant current state, preset constant current value. For I, the voltage value of RV2 is detected as: RV2b. The P4.0 port of the MCU outputs a low level. Leave the battery under test in an unloaded state. Calculate (RV2a- RV2b) / I, the calculation result is the DC internal resistance of the battery to be tested.

[0052] When the charger is used as an internal resistance tester, there are two power supply modes. One can be powered by an external power supply, and the other is to install a battery to be boosted by the internal circuit of the charger.

[0053] The charger of the embodiment is configured with an independent four-wire system test pen, and the battery internal resistance is tested by using a four-wire system, thereby improving the accuracy of the internal resistance of the test battery. In an embodiment, the charger body 2 and the test pen 1 The connected interface is one, and the conventional four or two interfaces are combined into one, and the structure is simple and convenient to use.

[0054]

[0055] The present invention has been described above using specific examples, but is merely used to help understand the present invention and is not used. Limit the invention. Variations to the above-described embodiments may be made by those skilled in the art in light of the concept of the invention.

technical problem

Problem solution

Advantageous effects of the invention

Claims

Claim

A charger capable of testing battery parameters, characterized by comprising:

a test pen comprising two pen body and a male/female port comprising at least four pins; wherein each of the pen body comprises a probe and two insulated wires, the front end of the probe is for Contacting the body to be tested, the rear end of the probe is electrically connected to one end of the two wires, and the other ends of the two wires are electrically connected to one pin of the male/female port respectively;

The charger body is configured to charge the battery after being used for external power supply; the charger body is provided with a female port/male port matching the male/female port of the interface of the test chart;

The four-wire test circuit is disposed in the charger body and electrically connected to the female/public port of the charger body for performing parameter test on the battery to be tested. The charger capable of testing battery parameters according to claim 1, wherein the interface is a USB interface, a mini-USB interface or a USB Type-C interface.

The charger for testing battery parameters according to claim 1 or 2, wherein the front end of the probe is planar and a plurality of projections are provided thereon.

A charger for testing battery parameters according to claim 1, wherein the outer surface of said probe is plated with gold.

The charger capable of testing battery parameters according to claim 1, wherein said probe comprises a probe sleeve and an inner needle movably disposed in said probe sleeve relative to said probe sleeve; said probe The sleeve includes a limiting portion at the rear end and a covering portion at the front end, and the limiting portion and the covering portion are connected by an elastic member.

The charger for testing battery parameters according to claim 5, wherein the meter body further comprises a casing disposed outside the two wires of the pen body, and one end of the casing abuts on the probe The limit of the sleeve.

The charger for testing battery parameters according to claim 1, wherein said four-wire test circuit performs parameter testing on the test battery, including internal resistance test and/or voltage test.

A charger capable of testing battery parameters according to claim 1 or 7, wherein The four-wire test circuit is a four-wire DC discharge internal resistance test circuit or a four-wire AC voltage drop internal resistance test circuit.

[Claim 9] The charger capable of testing battery parameters according to claim 1, further comprising a display unit disposed on the charger body for displaying the four-wire test circuit after testing the battery to be tested The parameters obtained.