JP2000050506A - Measuring power saving method for battery protection circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of testing a battery protection circuit, making use of general-purpose testing devices which are not required to be recombined every time the set voltage supplied from a power supply connected to the battery protecting circuit is changed and which are capable of testing whether or not the switching control of the battery protecting circuit is operated correctly. SOLUTION: A battery protecting circuit is provided with terminals 2, 3, 4 to which a secondary battery is connected when it is actually used, and terminals 5, 6 to which a load and a charge device are connected. In this battery protecting circuit, a power supply circuit 13 which supplies voltage to this battery protecting circuit is connected to the terminals 2, 3, 4. Constant current power supplies 14, 15 which supply current to the battery protecting circuit are each connected between the terminals 2 and 5, and between the terminals 4 and 6. Then, a test is conducted to check whether or not the battery protecting circuit operates correctly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery protection circuit test method for testing whether a battery protection circuit for protecting a chargeable / dischargeable battery operates normally.

[0002]

2. Description of the Related Art A conventional battery protection circuit will be described with reference to FIGS. FIG. 1 is a block diagram showing the configuration of the battery protection circuit. The battery protection circuit 1 has terminals 2 to 6
N-channel MOSFET transistors Q1 and Q2 connected in series between terminals 2 and 5, a current detection resistor R connected between terminals 4 and 6, and a potential difference between terminals 2 and 3. , The potential difference between the terminals 3 and 4 and the potential difference between both ends of the current detection resistor are measured.
This is a circuit having a protection IC 7 for controlling both the SFET transistors Q1 and Q2 to be ON.

[0003] The sources of the N-channel MOSFET transistors Q1 and Q2 are connected to the terminals 2 and 5 respectively, and the sources of the transistors Q1 and Q2 are connected to the terminals 2 and 5, respectively.
The drains of both transistors are connected. Also,
The gates of both transistors are connected to the protection IC 7.

The battery protection circuit 1 includes the current detection resistor R and the N-channel MOSFET transistor Q.
The battery protection circuit may be configured such that 1, Q2 is connected in series between the terminal 2 and the terminal 5 or between the terminal 4 and the terminal 6.

[0005] In the battery protection circuit 1 having such a configuration, the secondary battery B1 is connected between the terminals 2 and 3, and the secondary battery B2 is connected between the terminals 3 and 4. During discharge,
When one of the voltages of the secondary batteries B1 and B2 falls below the normal range, an over-discharge protection action is activated by the protection IC 7 to lower the gate voltage of the transistor Q2 and stop the operation of the transistor Q2, thereby discharging the battery. Cut the current.

[0006] Conversely, at the time of charging, the secondary batteries B1, B
When any one of the voltages exceeds the normal range, an overcharge protection function is activated by the protection IC 7, and the gate voltage of the transistor Q1 is lowered to stop the operation of the transistor Q1, thereby cutting the charging current. .

Further, during charging and discharging, an overcurrent flows through the current detection resistor R, and when the potential difference across both ends of the resistor R exceeds its normal range, overcurrent protection is activated by the protection IC 7, and the transistor is charged during charging. The operation of Q1 is stopped to cut the charging current, and the operation of the transistor Q2 is stopped at the time of discharging to cut the discharging current.

FIG. 5 is a block diagram showing a conventional test apparatus for performing a test for confirming the operation of the battery protection circuit 1. As shown in FIG. Bipolar power supplies 8 and 9 are connected as pseudo power supplies for a secondary battery that charges and discharges between terminals 2 and 3 and between terminals 3 and 4 of the battery protection circuit 1. Is connected, and the contact 10 of the switch 10
A charging device 11 is connected between the terminal a and the terminal 6, and a large-capacity load 12 whose load size is variable is connected between the contact 10 b of the switch 10 and the terminal 6.

Hereinafter, each of the conventional overdischarge test, overcharge test and overcurrent test using the test apparatus having the above configuration will be described.

In the overdischarge test, first, the switch 10 is set on the contact 10b side, and the battery protection circuit 1 is connected to the load 12 so that the secondary battery performs a discharging operation. At this time, the voltage of the bipolar power supply 8 or 9 is lowered while the discharge current ID is flowing, and it is confirmed whether or not the discharge current ID is cut when the voltage falls below its normal range.

In the overcharge test, first, the switch 10 is set to the contact 10a side, and the battery protection circuit 1 and the charging device 11 are connected to make the secondary battery perform a charging operation. At this time, the voltage of the bipolar power supply 8 or 9 is increased while the charging current IC is flowing, and it is confirmed whether or not the charging current IC has been cut off when the voltage exceeds its normal range.

In the overcurrent test, the contact 1 of the switch 10
By setting to the 0b side, a state in which the discharge current flows into the battery protection circuit 1 is set. At this time, by controlling the voltages of the bipolar power supplies 8 and 9 to a voltage in a normal range and operating the load 12 connected to the battery protection circuit 1, the discharge current flowing into the battery protection circuit 1 is increased. Then, when the current exceeds the normal range, it is confirmed whether or not the current has been cut.

It is extremely rare for an overcurrent to flow while the secondary battery is being charged.
An overcurrent test in a charged state is not generally performed.

[0014]

In the conventional battery protection circuit test method, the test is performed by connecting an actual load to the battery protection circuit 1 as described above. It is necessary to supply the harmful battery protection circuit 1 from the test device.

The power required for use in the test method is a voltage of 4 NV obtained by multiplying the number N of the rechargeable batteries connected in series by a voltage of 4 V of the rechargeable batteries, and further performing the test. 4N obtained by multiplying the required test current by 1 to 10A
It becomes a large power of ４０40 NW. For this reason, the bipolar power supply used in the test method also needs a power supply that supplies such a large amount of power, so that a device having a large capacity is required.

In the test method, not only the bipolar power supplies 8 and 9 need a large-capacity bipolar power supply device, but also the battery protection circuit 1 is simulated using the bipolar power supplies 8 and 9. Since the charging device 11 and the large-capacity load 12 for charging / discharging via the battery are also required, the test device used in the test method becomes large-scale.

Therefore, an object of the present invention is to provide a method for testing a battery protection circuit in which the power supply connected to the battery protection circuit 1 requires a small capacity.

Another object of the present invention is to provide a test method for a battery protection circuit that can be tested by a small-scale test apparatus.

Further, according to the conventional test method, assuming that the number of rechargeable batteries connected in series at the time of actual use changes and the voltage applied to the battery protection circuit 1 changes, When the bipolar power supplies 8 and 9 having different set voltages are connected to the battery protection circuit 1, the connected charging device 11 and the large-capacity load 12 must be changed to those having different capacities. Therefore, the charging device 11 and the large-capacity load 12 are required in various types,
Each time the set voltage of the bipolar power supply is changed, the test apparatus must be re-arranged.

In the present invention, in view of the above problems, it is not necessary to rearrange the test apparatus every time the magnitude of the set voltage supplied from the power supply connected to the battery protection circuit 1 is changed, and the battery protection circuit is not required. It is an object of the present invention to provide a test method of a battery protection circuit using a versatile test device capable of testing whether or not the operation of the first switching control is performed normally.

[0021]

According to the test method of a battery protection circuit of the present invention, a secondary battery connection terminal to which a chargeable / dischargeable secondary battery is connected, and a load connection terminal to which a load or a charging device is connected are provided. A voltage detector for detecting a voltage value of the secondary battery, a current detector for detecting a current value flowing from the secondary battery, and whether a voltage value detected by the voltage detector is higher than a predetermined voltage value. Or whether a battery protection circuit having an output control unit that shuts off a charge / discharge path of the secondary battery when a current value detected by the current detection unit exceeds a predetermined current value is working normally. In a test method of a battery protection circuit to be tested, a power supply for supplying a test voltage to a secondary battery connection terminal of the battery protection circuit and a test current between a secondary battery connection terminal and a load connection terminal of the battery protection circuit. Connect the constant current power supply to the secondary And performing connected to the battery protection circuit in place of.

According to the battery protection circuit testing method performed in such a configuration, it is not necessary to connect a load or a charging device actually used to the load connection terminal of the battery protection circuit unlike the conventional testing method. . In addition, the current value flowing through the power supply connected to the secondary battery connection terminal is reduced, and the voltage applied to the constant current power supply connected between the secondary battery connection terminal and the load connection terminal is reduced, so that the consumption of the test device is reduced. Reduce power.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
This will be described with reference to FIGS. FIG. 2 is a block diagram showing a configuration of a test device for confirming the operation of the battery protection circuit 1. FIG. 3 shows an example of a circuit diagram of the power supply circuit 13 of FIG. FIG. 4 shows the constant current power supplies 14, 1 in FIG.
5 is a simple circuit diagram showing the internal configuration of FIG.

In the present embodiment, the battery protection circuit 1 shown in FIG. 1 will be described as a test object. As in the conventional test method, the current detection resistor R and the N-channel MOSFET transistor Q other than the battery protection circuit shown in FIG.
A battery protection circuit having a configuration in which 1, Q2 are connected in series between the terminal 2 and the terminal 5 or between the terminal 4 and the terminal 6 may be used as a test object.

As shown in FIG. 2, a power supply circuit 13 is connected to the terminals 2 to 4 of the battery protection circuit 1, and between the terminals 2 and 5 of the battery protection circuit 1, and between the terminals 4 and 6. The constant current power supplies 14 and 15 are respectively connected between and. The power supply circuit 13 used at this time is actually the battery protection circuit 1.
Supplies a voltage at the time of charging and discharging when the battery protection circuit 1 is connected to the secondary battery, and one enough to operate the battery protection circuit 1.
The power supply circuit supplies a small amount of current up to mA.

An example in which an operational amplifier is used in the power supply circuit 13 will be described with reference to FIG. A resistor R1 is connected to the output terminal 16a of the controller 16,
A resistor R5 is connected to the output terminal 16b, and a resistor R is connected to the output terminal 16c.
3 and R7 are connected respectively. The resistance R1 and the resistance R
2 is connected to the negative input terminal A1a of the operational amplifier A1, and the connection node between the resistors R3 and R4 is connected to the positive input terminal A1b of the operational amplifier. The connection node between the resistors R5 and R6 is connected to the negative input terminal A2 of the operational amplifier A2.
a, and a connection node between the resistors R7 and R8 is connected to the positive input terminal A2b of the operational amplifier A2. The resistor R2
Is connected to the output terminal A1c of the operational amplifier A1 and the terminal 2 of the battery protection circuit 1. The other end of the resistor R4 and the other end of the resistor R6 are connected to the output terminal A2c of the operational amplifier A2. Connect to terminal 3 of protection circuit 1. Further, the other end of the resistor R8 is connected to the terminal 4 of the battery protection circuit 1.

The power supply circuit 13 as described above corresponds to FIG.
It is configured by combining power supply circuits as described above. FIG.
The power supply circuit (b) includes a resistor R11 connected to the positive side of a 3.5V power supply.
And a resistor R12 connected to the negative side, and a connection node between the resistor R11 and the resistor R13 is connected to the negative input terminal A of the operational amplifier A.
a, and the connection node between the resistors R12 and R14 is connected to the positive input terminal Ab of the operational amplifier A. The other end of the resistor R13 is connected to the output terminal Ac of the operational amplifier A and the terminal 1
7 and the other end of the resistor R14 is connected to 2V via the terminal 18.
To the positive side of the power supply. Further, the negative sides of the 3.5V power supply and the 2V power supply are grounded. At this time, the terminal 17
The potential difference between the terminal 17 and the terminal 18 is V11, and the voltage applied between the terminal 17 and the ground is V12.

In a circuit having a configuration as shown in FIG.
Assuming that the potentials applied to the terminals Ca, Cb, Cc, and Cd are V21, V22, V23, and V24, respectively, as shown in FIG. , V12 is V1
It becomes 5.5V from 2 = V11 + 2.

Therefore, the potential difference between the output terminals 16a and 16c of the controller 16 is V1.
If the potential difference between b and 16c is defined as V2, and the potentials of the terminals 2, 3, and 4 of the battery protection circuit 1 are defined as Va, Vb and Vc, respectively, when a power supply circuit as shown in FIG. Vb + V1, Vb = Vc + V2, and the voltage in the same state as when a secondary battery is connected in series is applied to the terminal 16a.
~ 16c.

The constant current power supplies 14 and 15 used in the test apparatus are power supplies capable of supplying a current of 1 to 10 A flowing when the battery protection circuit 1 is actually connected to a secondary battery. In the case of the constant current power supply 14, the direction of the current flowing from the power supply is terminal 2 → terminal 5 and terminal 5 → terminal 2 (in the case of the constant current power supply 15, terminal 4 → terminal 6 and terminal 6 → terminal 4 ) Is a power supply that can be converted in each direction. The voltage applied by the constant current power supplies 14 and 15 is a low voltage of up to 0.1V.

An example of the configuration of the constant current power supplies 14 and 15 will be described with reference to FIG. The constant current power supplies 14, 1
5 has current sources 20 and 21 for supplying constant currents, respectively, and switches 22 and
Reference numeral 23 denotes a switch connected to the terminal 2 and the terminal 5 of the battery protection circuit 1, and a three-point connection switch 24,
Reference numeral 5 is connected to the terminals 4 and 6 of the battery protection circuit 1, respectively. Two of the three contacts of the switches 22 and 23 are connected to the current source 20.
Similarly, for the switches 24 and 25, two of the three contacts of the switch are connected to the current source 21.
Connected to.

Of the contacts of the switches 22 to 25, the contacts connected to the current sources 20 and 21 include a contact a and a contact d, a contact b and a contact c, a contact e and a contact h, respectively.
Are connected to the contact point f and the contact point g. The current source 20 is in the direction of contact a → contact c (contact d → contact b), and the current source 21 is similarly contact e → contact g (contact h →
Current always flows in the direction of the contact f).

The constant current power supply 14 connected as described above,
15, the switch 22 in the constant current power supply 14 is connected to the contact a side, the switch 23 is connected to the contact c side, and the switch 24 in the constant current power supply 15 is connected.
Is connected to the contact f side, and the switch 25 is connected to the contact h side. At this time, the operation performed by the battery protection circuit 1 is the same as the operation performed when a charging device is connected to the terminals 5 and 6 of the battery protection circuit 1. That is, it is testing whether or not the operation for charging the secondary battery is performed normally.

Conversely, the switch 2 in the constant current power supply 14
2 is connected to the contact b side, and the switch 23 is connected to the contact d side. The switch 24 in the constant current power supply 15 is connected to the contact e side, and the switch 25 is connected to the contact g side. At this time, the operation performed by the battery protection circuit 1 is the same as the operation performed when a large-capacity load is connected to the terminals 5 and 6 of the battery protection circuit 1. That is,
This means that the operation for discharging the secondary battery is normally performed.

[0035]

According to the test method of the battery protection circuit of the present invention, the test at the time of charging and discharging can be performed only by changing the polarity of the constant current power supply connected to the battery protection circuit. Therefore, there is no need to connect a charging device or a load to the battery protection circuit.

According to the battery protection circuit test method of the present invention, the current supplied by the power supply for supplying the voltage to the battery protection circuit is large enough for the battery protection circuit to detect the voltage applied by the power supply. Since the current may be sufficient, the power supply can be constituted by a small-capacity power supply circuit using an operational amplifier.

According to the battery protection circuit test method of the present invention, the current supplied by the power supply for supplying voltage to the battery protection circuit is large enough for the battery protection circuit to detect the voltage applied by the power supply. And the voltage applied to the output control unit and the current detection unit by the constant current power supply that supplies the test current is low enough to operate the battery protection circuit. The power consumption of the test device is reduced.

Further, according to the battery protection circuit test method of the present invention, the power consumption of the test apparatus is reduced, so that the test apparatus used in the test method can be small.

Further, according to the battery protection circuit test method of the present invention, a constant current power supply for flowing a current during charging or discharging to the battery protection circuit in a simulated manner is connected to the battery protection circuit. Since the power supply for supplying the voltage of the rechargeable battery in a simulated manner is separate, the configuration of the apparatus that performs the test method such as changing the charging device and the load according to the voltage of the rechargeable battery as in the related art. Since there is no need to make a big change,
There is versatility of the device.

[Brief description of the drawings]

FIG. 1 is a block diagram of a battery protection circuit.

FIG. 2 is a block diagram of an apparatus for testing a battery protection circuit according to the present invention.

FIG. 3 is a power supply circuit for operating a control unit of the battery protection circuit.

FIG. 4 is a circuit diagram inside a constant current power supply for supplying a constant current to a battery protection circuit.

FIG. 5 is a block diagram of a conventional apparatus for testing a battery protection circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery protection circuit 2-6 terminal 7 Protection IC 8 Bipolar power supply 9 Bipolar power supply 10 Switch 11 Charger 12 Large capacity load 13 Power supply circuit 14 Constant current power supply 15 Constant current power supply 16 Controller 20 Current source 21 Current source 22-25 Switch

Claims (1)

[Claims] 1. A secondary battery connection terminal to which a chargeable / dischargeable secondary battery is connected, a load connection terminal to which a load or a charging device is connected, and a voltage detection unit for detecting a voltage value of the secondary battery. A current detection unit that detects a current value flowing from the secondary battery; and a voltage value detected by the voltage detection unit that is higher or lower than a predetermined voltage value, or a current value detected by the current detection unit. A battery protection circuit that tests whether or not a battery protection circuit having an output control unit that shuts off a charging / discharging path of the secondary battery when a current value exceeds a predetermined current value is operating normally. A power supply for supplying a test voltage to the secondary battery connection terminal of the battery protection circuit, and a constant current power supply for supplying a test current between the secondary battery connection terminal and the load connection terminal of the battery protection circuit, instead of the secondary battery Connected to the battery protection circuit The method of testing a battery protection circuit and performs with.