JP2000253595A - Charging method of a plurality of battery units - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent overcharging of battery units, even if one of the battery units is not operating normally and charge the remaining normal battery units to the full capacity successively. SOLUTION: A plurality of battery units 2 set in a charger 1 are switched in order to be charged. Each battery unit 2 inputs charging request signals and charging stop signals into the charger 1, and then the charger 1 detects the charging request signals and the charging stop signals input from the battery units 2 and successively charges the battery units 2. Each battery unit 2 inputs a plurality of charging request signals and a plurality of charging stop signals into the charger 1. Then the charger 1 starts charging each battery unit 2, detects all the charging request signals from the unit 2, and detects one of charging stop signals and stops charging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging method for sequentially charging a plurality of battery units.

[0002]

2. Description of the Related Art A charging method for sequentially charging battery units such as a pack battery has a feature that a plurality of battery units can be charged by reducing the power supply capacity of a charger. For example,
How to charge four battery units in order,
Four sets of battery units can be charged with a power supply capacity that can charge one set of battery units.

In a method of switching and charging a plurality of battery units in order, when a charged battery unit is fully charged, the battery units are switched to another one after another and charged.
As a charging method for realizing this, there is a method of inputting a charging request signal and a charging stop signal from a battery unit to a charger. In this charging method, the battery unit to be charged by the charger is switched based on a charge request signal and a charge stop signal input from the battery unit to the charger.

[0004] For example, when a charge request signal is input from a battery unit A to a battery charger to the charger, the charger selects one of the battery units A that has output the charge request signal and starts charging. When the battery unit A to be charged is fully charged, the battery unit A outputs a charge stop signal to the charger. The charger stops charging of the battery unit A in response to the charging stop signal of the battery unit A, and then starts charging of the battery unit B which has output the charging request signal. In this manner, the battery units A, B, C, and D are sequentially fully charged.

[0005]

A method for charging a battery unit by switching a battery unit to be charged in order from a charging request signal and a charging stop signal input from the battery unit is a method for charging a battery unit in an ideal state. Can be charged. However, in this charging method, one of the battery units does not operate normally, or a contact point between the battery unit and the charger causes a contact failure, and the charging battery unit issues a charge stop signal to the charger. If the input cannot be performed, the charger switches to the next battery unit and cannot be charged. For this reason, the remaining battery unit attached to the charger may not be able to be charged.

The disadvantage that the remaining battery units cannot be charged can be prevented, for example, by limiting the maximum charging time of the battery units with a timer or the like. However, in the method in which the charging time is limited by the timer, for example, a battery unit having a poor contact may be overcharged. This is because a plurality of battery units have different remaining capacities, so that the set time of the timer is set to a time at which a completely discharged battery unit can be fully charged. Furthermore, a battery unit that is not completely discharged is normally fully charged in a short time and is switched to the next battery unit, but since the timer is set to the longest time, it takes time to switch to the next battery unit. However, there is also a drawback.

[0007] The present invention has been developed for the purpose of solving such disadvantages. An important object of the present invention is to provide a method for charging a plurality of battery units, which can prevent overcharging of the battery units and fully charge the remaining battery units one after another even when one of the battery units does not operate normally. Is to provide.

[0008]

According to the method of charging a plurality of battery units of the present invention, a plurality of battery units 2 mounted on a charger 1 are sequentially switched and charged. Each battery unit 2 inputs a charging request signal and a charging stop signal to the charger 1, and the charger 1 detects the charging request signal and the charging stop signal input from the battery unit 2 and In order. Further, each battery unit 2 inputs a plurality of charge request signals and a charge stop signal to the charger 1. The charger 1 starts charging upon detecting all charging request signals, and stops charging upon detecting any one of the charging stop signals.

In the method of charging a plurality of battery units according to a second aspect of the present invention, the battery unit 2 inputs a plurality of charge request signals and a plurality of charge stop signals to the charger 1 through a plurality of transmission paths 10.

According to the method of charging a plurality of battery units of the present invention, the battery unit 2 is an electronic device or a battery pack containing the secondary battery 3.

According to the method of charging a plurality of battery units of the present invention, the charge request signal and the charge stop signal are digital signals of high and low.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify a method of charging a plurality of battery units 2 for embodying the technical idea of the present invention, and the present invention does not specify the charging method as follows.

Further, in this specification, in order to make it easier to understand the claims, the numbers corresponding to the members shown in the embodiments will be referred to as “claims” and “ In the column of “means”.
However, the members described in the claims are not limited to the members of the embodiments.

A battery charger 1 shown in FIG. 1 has a plurality of battery units 2 detachably mounted thereon, and charges a built-in secondary battery 3 one after another. The charger 1 in this figure charges four battery units 2 one after another.

The battery charger 1 includes a secondary battery 3 of a battery unit 2.
A power supply circuit 4 for outputting a voltage and a current for charging the battery; a charge control switch 5 connected to the output side of the power supply circuit 4 for switching and charging the secondary battery 3 of the battery unit 2; And a charge order control circuit 6 for controlling the control switch 5 to control the state of charge of the battery unit 2.

The output voltage and current of the power supply circuit 4 differ depending on the type of the secondary battery 3 built in the battery unit 2. The power supply circuit for charging the lithium ion secondary battery built in the battery unit controls the output with constant voltage and constant current,
First, constant current charging is performed, and when the battery voltage rises to a set voltage, for example, 4.1 to 4.2 V / cell, constant voltage charging is performed. A power supply circuit for charging a nickel-hydrogen battery or a nickel-cadmium battery charges the secondary battery with a charging current of, for example, 1C to 10C, with the output having a constant current characteristic.

The charge control switch 5 is connected between a branch on the output side of the power supply circuit 4 and a charging contact 8 connected to the charging terminal 7 of each battery unit 2. The charge control switch 5 turns on one of them in order to charge the secondary battery 3 of the battery unit 2. The charge control switch 5 is a transistor or an FET, and charges the battery unit 2 in an on state, and turns off to stop charging. The charge control switch 5 as a transistor is controlled by a signal input to the base, and the charge control switch as an FET is controlled to be turned on and off by a signal input to the gate. The charge control switch 5 in this figure is switched on and off, charges the battery unit 2 one after another, and stops charging when the battery unit 2 is fully charged. Set the charge control switch 5 to a transistor or FET
In the charger 1, the charge control switch 5 can be used in combination with a switching element for realizing constant voltage and constant current characteristics.

The charge order control circuit 6 controls the charge control switch 5 based on a charge request signal and a charge stop signal input from the battery unit 2 to charge the secondary batteries 3 of the battery unit 2 one after another.

The battery unit 2 detachably connected to the charger 1 includes a secondary battery 3 and a charging signal circuit 9. The secondary battery 3 of the battery unit 2 is a rechargeable battery such as a lithium ion secondary battery, a nickel-cadmium battery, and a nickel-hydrogen battery.

The charge signal circuit 9 detects the state of charge of the secondary battery 3 and outputs a charge request signal and a charge stop signal to the charger 1. The charge signal circuit 9 outputs a charge request signal when the secondary battery 3 needs to be charged, and is fully charged.
Alternatively, when the battery is charged to a predetermined capacity, a charge stop signal is output. The charge signal circuit 9 normally outputs a charge stop signal when the secondary battery 3 is fully charged. However, depending on the state of use, the life of the secondary battery 3 can be extended by outputting a charge stop signal in a state where the secondary battery 3 is not fully charged, for example, in a state of 80% of full charge.

The charge signal circuit 9 outputs a plurality of charge request signals and a charge stop signal. The battery unit 2 shown in FIG. 1 transmits a first charge request signal and a second charge request signal through two independent transmission paths 10 including a first transmission path 10A and a second transmission path 10B.
It outputs a charge request signal, a first charge stop signal, and a second charge stop signal. The first transmission path 10A transmits the first charge request signal and the first charge stop signal from the battery unit 2 to the charger 1, and the second transmission path 10B transmits the second charge request signal and the second charge stop signal.
The charging stop signal is transmitted to the charger 1. As described above, a structure in which a plurality of charge request signals and a charge stop signal are output from a plurality of output terminals 11 to the charger 1, in other words, a plurality of charge request signals and a charge The method of transmitting the stop signal to the charger 1 can achieve the highest reliability. This is because the charging request signal and the charging stop signal can be transmitted to the charger 1 via any one of the transmission lines 10 even if any of the output terminals 11 has a contact failure.

However, in the charging method of the present invention, a plurality of charging request signals and a charging stop signal can be output from the charging signal circuit to the charger by shifting the time on a single transmission line.
In this method, for example, when a predetermined number of charging request signals and a predetermined number of charging stop signals cannot be output due to a failure of a charging signal circuit, charging is stopped by one charging stop signal.

The charge request signal and the charge stop signal output by the charge signal circuit 9 are shown in the timing chart of FIG. In this figure, the first charge request signal is L → H, and the second charge request signal is H → L. The first charge stop signal is H → L, and the second charge stop signal is L → H. Thus, the charge request signal and the charge stop signal are changed from H →
The method of making a digital signal that is an L or L → H signal is as follows:
The battery unit can be switched in sequence and charged with a simple circuit. However, in the charging method of the present invention, the charging request signal and the charging stop signal are not necessarily digital signals, but may be, for example, tone signals of a specific frequency.

The charging signal circuit 9 outputs a charging request signal or a charging stop signal when a scanning signal is input from the charger 1 to the charging signal circuit 9, or the battery unit 2 is mounted on the charger 1. In this state, a charge request signal or a charge stop signal is output. In the method of outputting the charge request signal or the charge stop signal by the scanning signal, the order of charging the battery units 2 can be determined by specifying the order of the battery units 2 to be scanned on the charger 1 side. A method of always outputting a charge request signal or a charge stop signal in a state where the battery unit 2 is attached to the charger 1 is to charge the battery unit 2 in the order stored in the charger 1 in advance, or The battery units 2 are charged in the order of attachment.

The state in which the charger 1 of FIG. 1 charges the four battery units 2 will be described with reference to the timing chart of FIG. [Don't Charge Period] When the charger outputs a scanning signal to each battery unit but does not receive a charge request signal from the battery unit, the charging order control circuit of the charger turns off all charge control switches, The battery unit is not charged. In a charger that does not output a scanning signal, a charging request signal is not input from any of the battery units, so that the charging order control circuit turns off all charging control switches.

[Battery Unit A Charge Permission] When the battery unit A is mounted on the charger, the charge signal circuit of the battery unit A includes an L → H signal as a first charge request signal and a second charge request signal. An H → L signal is output to the charger. The charging order control circuit of the charger detects the first charging request signal and the second charging request signal, confirms that both charging request signals have been input, and switches the charging control switch A from off to on, The other charge control switches are kept off. In this state, the battery unit A is charged. When the secondary battery of the battery unit A is fully charged or charged to the set capacity, the charge signal circuit of the battery unit A includes an H → L signal as a first charge stop signal and a second charge stop signal. The L → H signal is transmitted to the charger. The charge order control circuit of the charger confirms that at least one of the first charge stop signal and the second charge stop signal has been input, switches the charge control switch A from on to off, and sets the battery unit A Stop charging.

[Charge permission of battery unit C] The charge signal circuit of the battery unit C mounted on the charger includes an L → H signal as a first charge request signal and an H → L signal as a second charge request signal. Is output to the charger. The charging order control circuit of the charger detects the first charging request signal and the second charging request signal, confirms that both charging request signals have been input,
The charge control switch C is switched from off to on, and the other charge control switches are kept off. In this state, the battery unit C is charged. When the secondary battery of the battery unit C is fully charged or charged to the set capacity, the charge signal circuit of the battery unit C includes an H → L signal as a first charge stop signal and a second charge stop signal. The L → H signal is transmitted to the charger. The charge order control circuit of the charger confirms that at least one of the first charge stop signal and the second charge stop signal has been input, switches the charge control switch C from on to off, and sets the battery unit C Stop charging.

In this charging step, the battery units B,
The charging signal circuit of D outputs the first charging request signal and the second charging request signal to the charger, but the charging order control circuit of the charger ignores this signal because the battery unit C is being charged. Then, the charging of the battery unit C is continued.

[Charging permission of battery unit D] When charging of the battery unit C is completed, the charging signal circuits of the battery units B and D output the L → H signal as the first charging request signal and the second charging request signal.
An H → L signal, which is a charge request signal, is output to the charger. The charging order control circuit of the charger switches the charging control switch D from off to on, giving priority to the first charging request signal and the second charging request signal input from the battery unit D,
The other charge control switches are kept off. In this state, the battery unit D is charged. When the secondary battery of the battery unit D is fully charged or charged up to the set capacity, the charge signal circuit of the battery unit D includes an H → L signal as a first charge stop signal and a second charge stop signal. L → H
Signal to the charger. The charging order control circuit of the charger confirms that at least one of the first charging stop signal and the second charging stop signal has been input, switches the charge control switch D from on to off, and sets the battery unit D
Stop charging.

[Battery Unit B Charge Permission] When the charging of the battery unit D is completed, the charging signal circuit of the battery unit B outputs an L → H signal as a first charge request signal and an H → H signal as a second charge request signal. → The L signal is output to the charger. The charging order control circuit of the charger gives priority to the first charging request signal and the second charging request signal input from the battery unit B,
The charge control switch B is switched from off to on, and the other charge control switches are kept off. In this state, the battery unit B is charged. When the secondary battery of the battery unit B is fully charged or charged to the set capacity, the charge signal circuit of the battery unit B includes an H → L signal as a first charge stop signal and a second charge stop signal. The L → H signal is transmitted to the charger. The charge order control circuit of the charger checks that at least one of the first charge stop signal and the second charge stop signal has been input, switches the charge control switch B from on to off, and sets the battery unit B Stop charging.

FIG. 2 shows a state in which all the circuits operate normally and the battery units A to D can be charged in order.
FIG. 3 shows a timing chart for charging the battery units A to D in order in a state where the battery unit D does not operate normally.

[Charging of Battery Unit D] When the charging of the battery unit C is completed, the charging signal circuits of the battery units B and D output the L → H signal as the first charging request signal and the second charging request signal.
An H → L signal, which is a charge request signal, is output to the charger. The charging order control circuit of the charger switches the charging control switch D from off to on, giving priority to the first charging request signal and the second charging request signal input from the battery unit D,
The other charge control switches are kept off. In this state, the battery unit D is charged.

In this charged state, when the secondary battery of the battery unit D is fully charged or charged to the set capacity, the charge signal circuit of the normal battery unit outputs the first charge stop signal, the H → L signal. And an L → H signal, which is a second charge stop signal, is transmitted to the charger.
Does not operate normally, so that L →
Although the H signal is output, the H → L signal as the first charge stop signal is not output. At this time, the charging order control circuit of the charger checks only the second charging stop signal, switches the charging control switch D from on to off, and sets the battery unit D
Stop charging. That is, the charging order control circuit stops charging of the battery unit D by one of the charging stop signals output from the battery unit D.

[Battery Unit B Charge Permission]
The charging of the battery unit B outputting the charging request signal and the second charging request signal is started, and charging is performed until the charging signal circuit of the battery unit B outputs a charging stop signal.

According to the charging method of the present invention, as described above, the battery unit outputs a plurality of charge stop signals, and any of the charge stop signals is detected, and the charger can stop charging. However, even if the battery unit fails and does not operate normally, all the battery units can be charged one after another. However, also in the charging method of the present invention, charging of the battery unit cannot be stopped in a state where the charging signal circuit of the battery unit does not output a charging stop signal at all. For this reason, the battery unit that outputs a plurality of charge stop signals outputs more charge stop signals, so that charging can be performed more reliably.

For reference, FIG. 4 shows a timing chart in which the charge signal circuit of the battery unit outputs a single charge stop signal and sequentially outputs the battery units.

[Don't Charge Period] When the charger outputs a scanning signal to each battery unit, but does not receive a charge request signal from the battery unit, the charging order control circuit of the charger turns off all the charge control switches. To make the battery unit not be charged.

[Battery Unit A Charge Permission] When the battery unit A is mounted on the charger, the charge signal circuit of the battery unit A outputs an L → H signal as a charge request signal to the charger. The charging order control circuit of the charger detects the charging request signal and switches the charging control switch A from off to on,
The other charge control switches are kept off. In this state, the battery unit A is charged. When the secondary battery of the battery unit A is fully charged, the charge signal circuit of the battery unit transmits an H → L signal, which is a charge stop signal, to the charger. The charge order control circuit of the charger checks the charge stop signal, switches the charge control switch A from on to off, and stops charging the battery unit A.

[Allow charging of battery unit C] The charging signal circuit of the battery unit C mounted on the charger outputs an L → H signal, which is a charging request signal, to the charger. The charge order control circuit of the charger checks the charge request signal, switches the charge control switch C from off to on, and keeps the other charge control switches off. In this state, the battery unit C is charged. When the secondary battery of the battery unit C is fully charged, the charge signal circuit of the battery unit C transmits an H → L signal, which is a charge stop signal, to the charger. The charge order control circuit of the charger checks the charge stop signal, switches the charge control switch C from on to off, and stops charging the battery unit C.

[Charging of Battery Unit D] When charging of the battery unit C is completed, the charging signal circuits of the battery units D and B output an L → H signal as a charging request signal to the charger. The charge order control circuit of the charger switches the charge control switch D from off to on, and holds the other charge control switches off, giving priority to the charge request signal input from the battery unit D. In this state, the battery unit D is charged.

When the rechargeable battery of the battery unit D is fully charged, the charge signal circuit of the battery unit outputs an H → L signal which is a charge stop signal. Is held. For this reason, the charging order control circuit of the charger continuously charges the battery unit D without turning off the charge control switch D. For this reason, while the battery unit D is overcharged,
The battery unit B to be charged next will not be charged.

[0042]

According to the method of charging a plurality of battery units of the present invention, even when one of the battery units does not operate normally, overcharging of the battery units is prevented and the remaining battery units are charged one after another. There are features that can be done. that is,
According to the method of charging a plurality of battery units of the present invention, a plurality of charge request signals and a charge stop signal are input to a charger from each battery unit, and the charger detects all charge request signals and performs charging. This is because, at the same time as starting, the charging is stopped by detecting any one of the charging stop signals, and the plurality of battery units mounted on the charger are switched and charged in order. In this charging method, as shown in FIG. 3, even if there is a battery unit that does not operate normally, any one of the charging stop signals is detected and charging is stopped, so that overcharging of the battery unit is prevented. In addition, the remaining battery units can be formed one after another. As in the conventional charging method shown in FIG.
A battery unit that does not operate properly does not overcharge the battery unit or prevent the remaining battery units from being charged. Therefore, the charging method of the present invention has a feature that even if there is a battery unit that does not operate normally, overcharging can be prevented and a plurality of battery units can be charged one after another safely.

In particular, according to the charging method of the present invention, the charger comprises:
Since charging is started by detecting all charging request signals among a plurality of charging request signals input from each battery unit, when a battery unit that does not operate normally is mounted, charging is not started without a dangerous operation. The state can be prevented from occurring. Further, since the charger detects any one of the plurality of charge stop signals input from each battery unit and stops charging, even if the battery unit does not operate normally, the charger can quickly operate. The overcharging can be effectively prevented by stopping charging.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a charger used in a charging method according to an embodiment of the present invention.

FIG. 2 is a timing chart showing a state of charging a plurality of battery units in which all circuits operate normally in the charging method according to the embodiment of the present invention.

FIG. 3 is a timing chart showing a state in which a battery unit that does not operate normally is charged by the charging method according to the embodiment of the present invention.

FIG. 4 is a timing chart showing a state of charging a battery unit that does not operate normally by the conventional charging method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Charger 2 ... Battery unit 3 ... Secondary battery 4 ... Power supply circuit 5 ... Charging control switch 6 ... Charging order control circuit 7 ... Charging terminal 8 ... Charging contact 9 ... Charging signal circuit 10 ... Transmission line 10A ... 1st transmission Road 1
0B: second transmission line 11: output terminal

Claims (4)

[Claims] 1. A charging method for sequentially charging a plurality of battery units (2) mounted on a charger (1), wherein each battery unit (2) includes a charge request signal and a charge stop signal. To the charger (1), and the charger (1)
In the charging method of sequentially charging each battery unit (2) by detecting the charge request signal and the charge stop signal input from (2), each battery unit (2) includes a plurality of charge request signals and a charge stop signal. A signal is input to the charger (1), the charger (1) detects all charging request signals and starts charging, and detects any one of the charging stop signals to stop charging. To charge multiple battery units. The battery unit (2) includes a plurality of transmission paths (10).
The method for charging a plurality of battery units according to claim 1, wherein a plurality of charge request signals and a charge stop signal are input to the charger (1). 3. The method for charging a plurality of battery units according to claim 1, wherein the battery unit (2) is an electronic device or a battery pack containing the secondary battery (3). 4. The method for charging a plurality of battery units according to claim 1, wherein the charge request signal and the charge stop signal are high and low digital signals.