JPH11233161A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack with a computing function of charge/ discharge repeating frequencies capable of obtaining the correlation of charge/ discharge repeating frequencies of a secondary battery and the actual deterioration degree of the battery. SOLUTION: A battery pack 1 has one or more secondary batteries, a measuring part 6 for measuring charge/discharge repeating frequencies of the battery, a display part 14 for displaying the measuring frequencies, and a communication circuit part for communicating the charge/discharge repeating frequencies to an appliance main body 2. The measuring part 6 has a function accumulating the discharge capacity of the secondary battery, and when the accumulated discharge capacity reached the set discharge capacity, measuring the charge/ discharge repeating frequency as one time, and resetting the accumulated capacity to zero.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention calculates the state of a battery during operation, such as the remaining capacity that can be discharged, and manages the state of the battery in the apparatus main body in order to manage the power of the device main body to which the battery is mounted. Battery Management Unit that outputs the indicated data
(hereinafter referred to as BMU) and supplies power to a load composed of a power tool such as a notebook computer or an electric screwdriver.

[0002]

2. Description of the Related Art In recent years, battery packs having a BMU function of calculating and outputting the number of repetitions of charge / discharge and the remaining capacity have been widely used.

The operation of this battery pack will be described below with reference to FIG.

FIG. 2 is a block diagram showing a conventional battery pack 1 having a function of counting the number of charge / discharge repetitions and a device main body 2.

[0005] The battery pack 1 and the equipment main body 2 have a positive terminal of the battery pack 1 and a positive terminal of the equipment main body 2, and a negative terminal of the battery pack 1 and a negative terminal of the equipment main body 2. And a data communication terminal b of the device main body 2 are electrically connected to each other by a connector or the like.

The current supplied from the battery pack to the equipment main body flows from the + terminal of the battery block 3 in which a plurality of secondary batteries are connected in series to the load 4 of the equipment main body 2, passes through the current detection resistor 5, Return to the negative terminal of block 3. The charge / discharge current flowing through the battery block 3 is represented by the potential difference between both ends of the current detection resistor 5 according to Ohm's law. The potential difference between both ends of the current detection resistor 5 is converted into a digital value by the AD conversion circuit 7. The charge / discharge detection circuit 8 detects whether the state is a charge state or a discharge state depending on whether the potential difference is positive or negative. If the state is a discharge state, the discharge current integration circuit 9 performs a discharge current integration calculation process.
When the battery switches from discharge to charge, the integrated discharge current is cleared to zero. The discharge capacity setting circuit 11 stores a preset discharge capacity, and the accumulated discharge capacity calculated by the discharge current integrating circuit 9 and the set discharge capacity stored in the discharge capacity setting circuit 11 correspond to the discharge capacity. The comparison is performed by the comparison circuit 12b. When the accumulated discharge capacity becomes equal to or larger than the set discharge capacity, a signal is sent from the discharge capacity comparison circuit 12b to the charge / discharge repetition number counter 13, and the charge / discharge repetition number counter 13 counts up by one.

[0007] The signal of the number of charge / discharge repetitions is output to the display unit 14, converted into communication data by the communication circuit unit 15, and passed through the data communication terminal a of the battery pack 1 and the data communication terminal b of the device body 2. Is input to the device main body circuit 16 and is subjected to arithmetic processing and the like as data of the battery pack 1 from the BMU.

[0008]

However, in the battery pack having the function of counting the number of repetitions of charging / discharging, the number of repetition of charging / discharging is counted by one when the accumulated discharge capacity value exceeds the set discharging capacity value. Although the operation is normal, the charge / discharge cycle is not repeated. When the charge / discharge cycle is repeated in a state where the accumulated discharge capacity value is less than the set discharge capacity value, the charge / discharge repeat count is not counted even though the charge / discharge cycle is repeated. For this reason, there was a problem that an appropriate correlation between the actual use state of the battery pack and the number of charge / discharge repetitions could not be obtained.

The present invention solves such a conventional problem and has a function of counting the number of times of repetition of charging and discharging so that the correlation between the actual use state of the battery pack and the number of times of recharging can be properly obtained. It is intended to provide a battery pack.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides one or more secondary batteries, a measuring unit for measuring the number of charge / discharge repetitions of the batteries, and a display of the number of measurements. And a communication circuit that communicates the number of charge / discharge repetitions to the device main body, wherein the measuring unit accumulates the discharged capacity of the secondary battery, and the accumulated discharge capacity becomes When the discharge capacity reached the set value, the number of charge / discharge repetitions was measured as one, and the function of resetting the accumulated discharge capacity to zero was provided.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a battery pack having the above-described contents, and in particular, accumulates discharged capacity of a secondary battery,
When this accumulated discharge capacity reaches the set discharge capacity,
It has a function of measuring the number of charge / discharge repetitions as one and resetting the accumulated discharge capacity to zero.

With such a configuration, even when the battery capacity is not fully used and the shallow discharge and charge are used repeatedly, the number of charge / discharge repetitions is grasped and the battery is deteriorated due to charge / discharge. The degree can be quantified correctly. That is, the battery pack can quantitatively determine the degree of aging, thereby greatly improving the maintainability of the battery pack and accurately controlling the device main body and the battery pack.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a battery pack 1 and a device main body 2 according to an embodiment of the present invention.

The battery pack 1 and the equipment main body 2 have a positive terminal of the battery pack 1 and a positive terminal of the equipment main body 2, and a negative terminal of the battery pack 1 and a negative terminal of the equipment main body 2. And a data communication terminal b of the device main body 2 are electrically connected to each other by a connector or the like. Reference numeral 4 denotes a load of the device main body 2, and reference numeral 5 denotes a current detection resistor. The direction of current during charging and discharging of the battery block 3 in which five nickel-hydrogen storage batteries are connected in series is detected as a potential difference between both ends of the current detection resistor 5. Reference numeral 6 denotes a measuring unit, 7 denotes an AD conversion circuit connected to one end of the resistor 5, 8
Is a charge / discharge detection circuit, 9 is a discharge current integration circuit, 10 is a discharge capacity integration circuit, 11 is a discharge capacity setting circuit, 12a is a discharge capacity comparison circuit, and 13 is a charge / discharge repetition number counter. Reference numeral 14 denotes a display unit, and 15 denotes a communication circuit unit. 1
Reference numeral 6 denotes a device main body circuit provided in the device main body 2.

Next, the operation of the battery pack according to the embodiment of the present invention will be described in detail. Potential difference between both ends of the current detection resistor 5 (data of current direction during charging and discharging)
Are converted into digital data by the AD conversion circuit 7. If the digital data is positive, the charge is performed, and if the digital data is negative, the discharge is performed. If the battery is in the discharging state, the discharging current integrating circuit 9 performs a current integrating operation. The integrated discharge capacity calculated by the discharge current integrating circuit 9 is the discharge capacity accumulating circuit 1
It is input to 0, where the accumulation operation is performed.

The accumulated discharge capacity and the discharge capacity setting circuit 1
The set discharge capacity set to 1 is the discharge capacity comparison circuit 1
When the accumulated discharge capacity is equal to the set discharge capacity, the charge / discharge repetition number counter 13 is counted up by one and the accumulated discharge capacity of the discharge capacity accumulation circuit 10 is reset to 0 at the same time.

The number of charge / discharge repetitions obtained by the charge / discharge repetition counter 13 is output to the display unit 14 and transmitted from the communication circuit 15 through the data communication terminal a of the battery pack 1 and the data communication terminal b of the device body 2 to the device. The data is sent to the device main body circuit 16 in the main body 2 and is used in arithmetic processing and the like as charge / discharge repetition count data of the battery pack 1 from the BMU.

After resetting the cumulative discharge capacity to 0, the discharge capacity accumulating circuit 10 restarts the accumulating operation in response to an input signal from the discharge current integrating circuit 9, and the above-described counting operation is repeated.

[0020]

As described above, in the battery pack of the present invention, in addition to counting up the charge / discharge repetition number counter by one when the battery is discharged to the set discharge capacity after charging, the battery capacity is completely reduced. Even if shallow discharge and charge are repeated without using up, the charge / discharge repeat counter counts up by one even when the accumulated discharge capacity accumulated by the discharge capacity accumulation circuit reaches the set discharge capacity. Therefore, the correlation between the actual use state of the battery and the calculated number of charge / discharge repetitions can be properly obtained, and excellent maintenance of the battery pack can be performed. Further, by accurately grasping the number of repetition of charge / discharge of the battery, the data can be used to accurately control the battery pack and the device body.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a battery pack and a device main body according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a conventional battery pack and a device main body.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 battery pack 2 device body 3 battery block 4 load 5 current detection resistor 6 measuring unit 7 AD conversion circuit 8 charge / discharge detection circuit 9 discharge current integration circuit 10 discharge capacity accumulation circuit 11 discharge capacity setting circuit 12 a discharge capacity comparison circuit 13 charge / discharge Repeat counter 14 Display unit 15 Communication circuit unit 16 Main unit circuit

Claims (1)

[Claims] 1. One or a plurality of secondary batteries, a measuring unit for measuring the number of charge / discharge repetitions of the battery, a display unit for displaying the number of recharges, and communication of the number of charge / discharge repetitions to the device body A communication circuit unit that performs the charging / discharging operation when the measuring unit accumulates the discharged capacity of the secondary battery and the accumulated discharging capacity reaches a set discharging capacity. A battery pack having a function of counting up the number of repetitions by one and resetting the accumulated discharge capacity to zero.