JP2012253888A - Charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charger capable of having a simplified charging system and dealing with a charging of various kinds of secondary batteries.SOLUTION: A charger 1 comprises: a characteristics acquisition section 10; a charging voltage detection section 20; a charging current determination section 30; and a charging current supplying section 40. The characteristics acquisition section 10 acquires, from a secondary battery BT, initial information on the battery side with respect to characteristics of the secondary battery BT. The charging voltage detection section 20 detects a charging voltage Vof the secondary battery BT. The charging current determination section 30, using the initial information on the battery side, determines a current value of charging current Iin accordance with the charging voltage Vof the secondary battery BT detected by the charging voltage detection section 20. The charging current supplying section 40 supplies the charging current Ihaving a current value determined by the charging current determination section 30 to the secondary battery BT.

Description

  The present invention relates to a charging device.

  Conventionally, a charging device for charging a secondary battery has been proposed (see, for example, Patent Document 1). The charging device disclosed in Patent Literature 1 includes a controller that determines a charging current to be supplied to the secondary battery according to the charging voltage of the secondary battery.

  The above-mentioned controller monitors the charging voltage of the secondary battery, and reduces the charging current value stepwise each time the charging voltage value reaches a predetermined threshold value. According to this, by setting the threshold value to be equal to or lower than the voltage value of the end-of-charge voltage, it is possible to prevent the charge voltage of the secondary battery from becoming higher than the end-of-charge voltage. Deterioration can be suppressed.

JP-A-11-89106

  There are various types of secondary batteries, and the characteristics of secondary batteries differ depending on the type of secondary battery. For this reason, the voltage value of the charge end voltage, which is one of the characteristics of the secondary battery, also differs depending on the type of the secondary battery. Therefore, in order to prevent overcharging, the above threshold value must be set according to the type of the secondary battery, and the current value of the charging current must be determined using the characteristics of the secondary battery to be charged.

  The controller shown in Patent Document 1 stores the characteristics of the secondary battery in advance. For this reason, it is necessary to manufacture a controller according to the type of the secondary battery, and the controller must be changed every time the type of the secondary battery charged by the charging device is changed. Therefore, when the charging system is constructed with the secondary battery and the charging device, it is difficult to simplify the charging system.

  In view of the above-described problems, an object of the present invention is to provide a charging device that can simplify a charging system and can support charging of various types of secondary batteries.

The present invention proposes the following items in order to solve the above-described problems.
(1) The present invention is a charging device (for example, equivalent to the charging device 1 in FIG. 1) for charging a secondary battery (for example, equivalent to the secondary battery BT in FIG. 1), and the characteristics of the secondary battery (For example, equivalent to the battery side initial information configured to include seven types of information shown in Table 2) characteristic acquisition means (for example, equivalent to the characteristic acquisition unit 10 of FIG. 2), and the characteristic acquisition means Using the acquired characteristic of the secondary battery, a current value of a charging current (for example, corresponding to the charging current I _CHG in FIG. 1) supplied to the secondary battery is set to a charging voltage (for example, Charging current determining means (for example, corresponding to the charging current determining unit 30 in FIG. 2) determined according to the charging voltage V _BT of the secondary battery BT in FIG. 1 and the current determined by the charging current determining means Charge current supplier for supplying a value of charge current to the secondary battery (E.g., corresponding to the charging current supply unit 40 of FIG. 2) proposes a charging device, characterized in that it comprises a, a.

  According to this invention, the characteristic acquisition means, the charging current determination means, and the charging current supply means are provided in the charging device that charges the secondary battery. And it was decided to acquire the characteristic of a secondary battery by a characteristic acquisition means. Further, the charging current determining means determines the current value of the charging current supplied to the secondary battery according to the charging voltage of the secondary battery, using the characteristics of the secondary battery acquired by the characteristic acquiring means. did. Further, the charging current supply unit supplies the charging current having the current value determined by the charging current determination unit to the secondary battery.

  Therefore, the characteristics of the secondary battery can be acquired and reflected in the charging current. Therefore, charging according to the characteristics of the secondary battery can be performed without changing the controller when changing the type of the secondary battery to be charged. Therefore, even if a controller is not manufactured or changed according to the type of the secondary battery, it is possible to support charging of various types of secondary batteries, and the charging system can be simplified.

  (2) In the charging device according to (1), the charging current determination unit is configured to determine a charging current and a charging voltage of the secondary battery based on the characteristics of the secondary battery acquired by the characteristics acquisition unit. Using the relationship acquisition procedure (for example, equivalent to the processing of steps S9 to S14 in FIG. 5) and the relationship determined in the relationship acquisition procedure, the current value of the charging current supplied to the secondary battery is calculated. And a current value determination procedure determined according to the charging voltage of the secondary battery (e.g., corresponding to steps S17 to S22 in FIG. 6 and steps S23 to S30 in FIG. 7). Has proposed a charging device.

  According to the present invention, the relationship acquisition procedure and the current value determination procedure are performed by the charging current determination means. In the relationship acquisition procedure, the relationship between the charging current and the charging voltage of the secondary battery is obtained based on the characteristics of the secondary battery acquired by the characteristic acquisition means. In the current value determination procedure, the current value of the charging current supplied to the secondary battery is determined according to the charging voltage of the secondary battery using the relationship obtained in the relationship acquisition procedure. For this reason, the effect similar to the effect mentioned above can be produced.

  (3) The present invention relates to the charging device according to (2), wherein the charging current determination unit is configured to determine the secondary battery based on the characteristics of the secondary battery acquired by the characteristic acquisition unit in the relationship acquisition procedure. A mathematical expression (for example, equivalent to mathematical expressions shown in equations (1), (4), and (6) described later) representing the relationship between the charging current and the charging voltage is determined, and in the current value determination procedure, the relationship acquisition procedure is determined. Proposing a charging device characterized in that the current value of the charging current to be supplied to the secondary battery is determined according to the charging voltage of the secondary battery by calculating in real time using the formula determined in is doing.

  According to this invention, in the relationship acquisition procedure by the charging current determining means, the mathematical expression indicating the relationship between the charging current and the charging voltage of the secondary battery based on the characteristics of the secondary battery acquired by the characteristic acquiring means. It was decided to decide. Further, in the current value determination procedure, the current value of the charging current supplied to the secondary battery is determined according to the charging voltage of the secondary battery by calculating in real time using the formula determined in the relationship acquisition procedure. It was decided to.

  For this reason, the current value of the charging current can follow the change in the charging voltage of the secondary battery in real time. Therefore, compared with the charging device shown in Patent Document 1, the time until the secondary battery is fully charged can be shortened.

  (4) According to the present invention, in the charging device of (3), the charging current determination unit stores a plurality of the mathematical expressions, and the plurality of mathematical expressions according to characteristics of the secondary battery in the relationship acquisition procedure. 1 (for example, corresponding to the processing of steps S9 to S14 in FIG. 5), and in the current value determination procedure, the formula selected in the relationship acquisition procedure is used for the calculation. Has proposed.

  According to the present invention, the charging current determination means stores a plurality of mathematical expressions, and in the relationship acquisition procedure, one of the mathematical expressions is selected according to the characteristics of the secondary battery, and in the current value determination procedure, The mathematical formula selected in the relationship acquisition procedure is used for the calculation. For this reason, by setting the plurality of mathematical formulas stored in the charging current determining means in consideration of the characteristics of various types of secondary batteries, it is possible to cope with charging of various types of secondary batteries.

  (5) The present invention relates to a charging device according to any one of (1) to (4). Has been proposed.

  According to the present invention, the charging voltage detecting means for detecting the charging voltage of the secondary battery is further provided. For this reason, even if the means for detecting the charging voltage of the secondary battery is not provided outside the charging device, the same effect as described above can be obtained.

  (6) The present invention proposes a charging apparatus according to any one of (1) to (5), wherein the secondary battery is a lithium ion battery.

  According to the present invention, a lithium ion battery is used as the secondary battery.

  Here, a secondary battery such as a lithium ion battery or a nickel metal hydride battery has an internal impedance. For this reason, when a charging current is supplied to the secondary battery, a current also flows through the internal impedance, and a potential difference due to the internal impedance occurs due to Ohm's law. However, if a potential difference occurs due to internal impedance during charging, the secondary battery cannot be fully charged. Therefore, in order to bring the secondary battery to a fully charged state, it is necessary to reduce the current value of the charge termination current and reduce the potential difference due to the internal impedance.

  A lithium ion battery has a characteristic that a large current can flow during charging / discharging although the internal impedance is lower than that of a secondary battery other than a lithium ion battery. For this reason, the potential difference generated by the internal impedance during charging may be larger in the lithium ion battery than in the secondary battery other than the lithium ion battery due to Ohm's law. Therefore, in particular, in the lithium ion battery, it is preferable that the current value of the charge end current can be set small in order to obtain a fully charged state as compared with the secondary battery other than the lithium ion battery.

  The charging device of (1)-(5) acquires the characteristic of a secondary battery as mentioned above. For this reason, even if it is a case where a lithium ion battery is used as a secondary battery by including the electric current value of the charge termination current suitable for the secondary battery to charge in the characteristic of the acquired secondary battery, the secondary battery Can be fully charged.

  According to the present invention, it is possible to handle charging of various types of secondary batteries and to simplify the charging system without manufacturing or changing a controller according to the type of secondary battery.

It is a block diagram of a charging system provided with the charging device which concerns on one Embodiment of this invention. It is a block diagram of the said charging device. It is a figure which shows the relationship between the charging current and charging voltage of a secondary battery with which the said charging system is provided. It is a flowchart of the charging operation by the said charging device. It is a flowchart of the charging operation by the said charging device. It is a flowchart of the charging operation by the said charging device. It is a flowchart of the charging operation by the said charging device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the constituent elements in the following embodiments can be appropriately replaced with existing constituent elements, and various variations including combinations with other existing constituent elements are possible. Accordingly, the description of the following embodiments does not limit the contents of the invention described in the claims.

FIG. 1 is a block diagram of a charging system AA including a charging device 1 according to an embodiment of the present invention. Charging system AA includes secondary battery BT in addition to charging device 1. Charging apparatus 1 detects the charging voltage _{V BT} of the secondary battery BT, supplies a charging current _{I CHG} having a current value corresponding to the detection result to the secondary battery BT.

[Configuration of Charging Device 1]
FIG. 2 is a block diagram of the charging device 1. The charging device 1 includes a characteristic acquisition unit 10, a charging voltage detection unit 20, a charging current determination unit 30, and a charging current supply unit 40.

  The characteristic acquisition unit 10 includes, for example, a CPU (Central Processing Unit) and a RAM (Random Access Memory). The characteristic acquisition unit 10 operates according to a program stored in a storage unit configured by, for example, a hard disk or a semiconductor memory and operates from the secondary battery BT to battery-side initial information on the characteristics of the secondary battery BT (table described later). 2).

The charging voltage detection unit 20 includes, for example, a voltage detector. The charging voltage detecting unit 20, during operation of the charging device 1, always detects the charging voltage V _BT of the secondary battery BT.

The charging current determination unit 30 includes, for example, the above-described CPU and RAM. The charging current determination unit 30 operates, for example, according to the above-described program, and the battery side initial information acquired by the characteristic acquisition unit 10 and the charging device side initial information related to the charging characteristics of the charging device 1 (see Table 1 described later). The current value of the charging current I _CHG is determined according to the charging voltage V _BT of the secondary battery BT detected by the charging voltage detection unit 20.

The charging current supply unit 40 includes, for example, a constant current source. The charging current supply unit 40 supplies the charging current I _CHG having the current value determined by the charging current determination unit 30 to the secondary battery BT.

[Operation of Charging Device 1]
The charging device 1 having the above configuration determines the current value of the charging current I _CHG according to the charging voltage V _BT of the secondary battery BT by calculation in real time, as shown in FIG. The charging operation by the charging device 1 will be described in detail below with reference to FIGS.

  In step S1 shown in FIG. 4, the charging current determination unit 30 reads the above-described charging device side initial information, and the process proceeds to step S2. The charging device side initial information is stored in a storage unit configured by, for example, a hard disk or a semiconductor memory, and includes four types of information shown in Table 1.

Chargeable maximum voltage value V ₂₁ is the maximum value of the charging voltage of the secondary battery charging apparatus 1 can be charged, chargeable minimum voltage value V ₂₂ is the minimum charging voltage of the secondary battery charging apparatus 1 can be charged Indicates the value. The maximum chargeable current value I ₂₁ indicates the maximum value of the current that can be output by the charging apparatus 1, and the minimum chargeable current value I ₂₂ indicates the minimum value of the current that can be output by the charging apparatus 1.

  The above four types of information shown in Table 1 are information unique to the charging device 1.

  In step S2, the above-mentioned battery side initial information is acquired from the secondary battery BT by the characteristic acquisition unit 10, and the process proceeds to step S3. The battery side initial information includes seven types of information shown in Table 2.

Charge voltage value V ₁₁ indicates the voltage value of the charge voltage of the secondary battery BT, the discharge termination voltage value V ₁₂ indicates the voltage value of the discharge end voltage of the secondary battery BT. The initial current value I ₁₁ is the optimum value of the charging current I _CHG when V ₁₂ <V _BT ≦ V ₁₃ , and the final current value I ₁₂ is the charging current I _CHG when V ₁₄ <V _BT <V _11. Is the optimal value. The charging pattern PT is a value determined according to the charging characteristics of the secondary battery BT. In the present embodiment, any one of PT1, PT2, and PT3 can be taken as shown in FIG.

Step down minimum voltage value _{V 13} and step down the maximum voltage value _{V 14} indicates the threshold value. Specifically, as shown by the broken line, the one-point difference line, or the two-point difference line in FIG. 3, the state in which the charging current I _CHG is decreased as the charging voltage V _BT of the secondary battery BT increases is stepped down. This is called a state. Then, the step-down minimum voltage value V ₁₃ indicates the minimum value of the charging voltage V _BT of the secondary battery BT in the step-down state, and the step-down maximum voltage value V ₁₄ is the charging voltage of the secondary battery BT in the step-down state. The maximum value of _VBT is shown.

  The seven types of information shown in Table 2 are determined according to the type of secondary battery connected to the charging device 1 as the secondary battery BT.

In step S <b> 3, the charging current determination unit 30 compares the maximum chargeable voltage value V <b> ₂₁ and the charge end voltage value V <b> ₁₁ . Then, when the chargeable maximum voltage value V ₂₁ is charge voltage value V ₁₁ or more, the process proceeds to step S4. Meanwhile, since the chargeable maximum voltage value V ₂₁ if it is less than the charging end voltage value V ₁₁ is that it can not be fully charged secondary battery BT in the charging apparatus 1, the secondary battery The error log is transmitted to the BT, and the charging operation by the charging device 1 shown in FIGS.

In step S4, the charging current determining unit 30, compares the chargeable minimum voltage value _{V 22} and discharge end voltage value _{V 12.} Then, when the chargeable minimum voltage value V ₂₂ is discharge end voltage value V ₁₂ or less, the process proceeds to step S5. On the other hand, when the chargeable minimum voltage value V ₂₂ is greater than the discharge termination voltage value V _12, because is that it is not possible to charge the secondary battery BT in the charging apparatus 1, the error log to the secondary battery BT The charging operation by the charging device 1 shown in FIGS.

In step S5, the charging current determination unit 30 compares the chargeable maximum current value _{I 21} and the initial current value _{I 11.} Then, when the chargeable maximum current value I ₂₁ is the initial current value I ₁₁ or more, the process proceeds to step S6. On the other hand, when the maximum chargeable current value I ₂₁ is less than the initial current value I ₁₁ , the charging current having the optimum current value from the charging device 1 to the secondary battery BT is satisfied when V ₁₂ <V _BT ≦ V _13. Since I _CHG cannot be supplied, an error log is transmitted to the secondary battery BT, and the charging operation by the charging device 1 shown in FIGS.

In step S <b> 6, the charge current determination unit 30 compares the chargeable minimum current value I ₂₂ with the end current value I ₁₂ . If the minimum chargeable current value I ₂₂ is equal to or less than the end current value I ₁₂ , the process proceeds to step S7. On the other hand, when the chargeable minimum current value _{I 22} is greater than the end current value _{I 12 is,} V ₁₄ <In the case of V BT _{<V 11,} the charging current I of the optimum current value from the charging device 1 to the secondary battery BT _{Since CHG} cannot be supplied, an error log is transmitted to the secondary battery BT, and the charging operation by the charging device 1 shown in FIGS.

In step S7, the charging current determining unit 30, compares the chargeable maximum voltage value _{V 21} and step-down the minimum voltage value _{V 13.} Then, when the chargeable maximum voltage value V ₂₁ is the step down minimum voltage value V ₁₃ or more, the process proceeds to step S8. On the other hand, when the rechargeable maximum voltage value V ₂₁ is less than the step-down minimum voltage value V ₁₃ , the secondary battery BT cannot be fully charged in the charging device 1. An error log is transmitted to the battery BT, and the charging operation by the charging device 1 shown in FIGS.

In step S8, the charging current determining unit 30 compares the chargeable minimum voltage value _{V 22} and step-down maximum voltage value _{V 14.} Then, when the chargeable minimum voltage value V ₂₂ is equal to or less than the step-down the maximum voltage value V _14, the process proceeds to step S9 in FIG. 5. On the other hand, the chargeable minimum voltage value V ₂₂ is larger than the step-down the maximum voltage value V ₁₄ is the charging voltage V _BT is the secondary battery BT charging apparatus 1 of the full charge is less than the step-down the maximum voltage value V ₁₄ Therefore, the error log is transmitted to the secondary battery BT, and the charging operation by the charging device 1 shown in FIGS.

  In step S9 of FIG. 5, the charging current determination unit 30 determines whether or not the charging pattern PT acquired in step S2 is PT1. If it is PT1, the process proceeds to step S10. If it is not PT1, the process proceeds to step S11.

  In step S10, the charging current determination unit 30 sets a first charging current calculation formula shown in the following formula (1), and the process proceeds to step S15.

The above equation (1) represents a linear curve indicated by a broken line in FIG. 3, and x ₁ and y _{1 in} the equation (1) are obtained from the following equations (2) and (3), respectively. Ask.

  In step S11, the charging current determination unit 30 determines whether or not the charging pattern PT acquired in step S2 is PT2. If it is PT2, the process proceeds to step S12. If it is not PT2, the process proceeds to step S13.

  In step S12, the charging current determination unit 30 sets a second charging current calculation formula shown in the following formula (4), and the process proceeds to step S15.

The above equation (4) represents a quadratic curve indicated by a one-dot chain line in FIG. 3, and x _{2 in the} equation (4) is obtained from the following equation (5).

  In step S13, the charging current determination unit 30 determines whether or not the charging pattern PT acquired in step S2 is PT3. If it is PT3, the process proceeds to step S14, and if it is not PT3, the charging operation by the charging device 1 shown in FIGS.

  In step S14, the charging current determination unit 30 sets a third charging current calculation formula in the following formula (6), and the process proceeds to step S15.

The above equation (6) represents a quadratic curve shown by a two-dot chain line in FIG. 3, for x ₃ of the formula (6) is obtained from the following equation (7).

In step S15, the charging current determining unit 30, the charging voltage _{V BT} of the secondary battery BT obtains from the charging voltage detector 20, the process proceeds to step S16.

In step S16, it compares the charging current determining unit 30, the charging voltage _{V BT} of the obtained secondary battery BT and discharge end voltage value _{V 12} at step S15. When the charging voltage _{V BT} of the secondary battery BT is greater than the discharge termination voltage value _{V 12} is transferred to step S17 in FIG. 6, the charging voltage _{V BT} discharge termination voltage value _{V 12} of the secondary battery BT In the following cases, since the secondary battery BT is in an overdischarged state, the charging operation by the charging device 1 shown in FIGS.

In step S17 in FIG. 6, the charging current determining unit 30, compares the charging voltage _{V BT} and steps down the minimum voltage value _{V 13} of the secondary battery BT acquired in step S15. When the charging voltage _{V BT} of the secondary battery BT is greater than the step-down the minimum voltage value _{V 13} is transferred to step S19, the secondary battery BT of the charging voltage _{V BT} following steps down the minimum voltage value _{V 13} If so, the process proceeds to step S18.

In step S18, the charging current determining section 30, the current value of the charging current _{I CHG,} set to an initial current value _{I 11,} the process proceeds to step S23 in FIG. 7. According to this, the charging current I _CHG having a current value equal to the initial current value I ₁₁ is supplied from the charging current supply unit 40 to the secondary battery BT.

In step S19, the charging current determining unit 30, compares the charging voltage _{V BT} and steps down the maximum voltage value _{V 14} of the obtained secondary battery BT in step S15. When the charging voltage _{V BT} of the secondary battery BT is greater than the step-down the maximum voltage value _{V 14} is transferred to step S21, the charging voltage _{V BT} of the secondary battery BT is less steps down the maximum voltage value _{V 14} If so, the process proceeds to step S20.

In step S20, the charging current determining unit 30 sets the current value of the charging current I _{CHG so} as to be obtained by the charging current calculation formula set in any of steps S10, S12, and S14, and the process proceeds to step S26 in FIG. Move. According to this, the charging current I _CHG having the current value obtained from the charging current calculation formula set in any of steps S10, S12, and S14 is supplied from the charging current supply unit 40 to the secondary battery BT. .

In step S21, it compares the charging current determining unit 30, the charging voltage _{V BT} of the obtained secondary battery BT and charge voltage value _{V 11} at step S15. When the charging voltage V _BT of the secondary battery BT is charge voltage value V ₁₁ or more, since the secondary battery BT is fully charged, the charging operation by the charging device 1 shown in FIGS. 4-7 End. On the other hand, when the charging voltage _{V BT} of the secondary battery BT is lower than the charging end voltage value _{V 11,} the process proceeds to step S22.

In step S22, the charging current determining section 30, the current value of the charging current _{I CHG,} set the cut-off current value _{I 12,} the process proceeds to step S29 in FIG. 7. According to this, the charging current I _CHG having a current value equal to the end current value I ₁₂ is supplied from the charging current supply unit 40 to the secondary battery BT.

In step S23 in FIG. 7, the charging current determining unit 30, the charging voltage _{V BT} of the secondary battery BT obtains from the charging voltage detector 20, the process proceeds to step S24.

In step S24, the charging current determining unit 30, compares the charging voltage _{V BT} and steps down the minimum voltage value _{V 13} of the secondary battery BT acquired in step S23. When the charging voltage _{V BT} of the secondary battery BT is greater than the step-down the minimum voltage value _{V 13} is transferred to step S25, the secondary battery BT of the charging voltage _{V BT} following steps down the minimum voltage value _{V 13} If so, the process returns to step S23. According to this, as shown in FIG. 3, in a state where V ₁₂ <V _BT ≦ V ₁₃ , the charging current I _CHG having a current value equal to the initial current value I ₁₁ is secondary from the charging current supply unit 40. The battery BT continues to be supplied.

In step S25, the charging current determining unit 30 sets the current value of the charging current I _{CHG so} as to be obtained by the charging current calculation formula set in any of steps S10, S12, and S14, and the process proceeds to step S26.

In step S26, the charging current determining unit 30, the charging voltage _{V BT} of the secondary battery BT obtains from the charging voltage detector 20, the process proceeds to step S27.

In step S27, the charging current determining unit 30, compares the charging voltage _{V BT} and steps down the maximum voltage value _{V 14} of the obtained secondary battery BT in step S26. When the charging voltage _{V BT} of the secondary battery BT is greater than the step-down the maximum voltage value _{V 14} is transferred to the processing in step S28, the charging voltage _{V BT} of the secondary battery BT is less steps down the maximum voltage value _{V 14} If YES, the process returns to step S26. According to this, as shown in FIG. 3, in a state where V ₁₃ <V _BT ≦ V ₁₄ , the charging current I _CHG having a current value determined by the charging current calculation formula corresponding to the charging pattern PT is the charging current supply. Continued to be supplied from the unit 40 to the secondary battery BT.

In step S28, the charging current determining section 30, the current value of the charging current _{I CHG,} set the cut-off current value _{I 12,} the process proceeds to step S29.

In step S29, the charging current determining unit 30, the charging voltage _{V BT} of the secondary battery BT obtains from the charging voltage detector 20, the process proceeds to step S30.

In step S30, it compares the charging current determining unit 30, the charging voltage _{V BT} of the obtained secondary battery BT and charge voltage value _{V 11} at step S29. When the charging voltage V _BT of the secondary battery BT is charge voltage value V ₁₁ or more, since the secondary battery BT is fully charged, the charging operation by the charging device 1 shown in FIGS. 4-7 End. On the other hand, when the charging voltage _{V BT} of the secondary battery BT is lower than the charging end voltage value _{V 11} returns the process to step S29. According to this, as shown in FIG. 3, in the state where V ₁₄ <V _BT <V ₁₁ , the charging current I _CHG having a current value equal to the end current value I ₁₂ is secondary from the charging current supply unit 40. The battery BT continues to be supplied.

  According to the above charging device 1, the following effects can be produced.

The charging device 1 acquires battery-side initial information related to the characteristics of the secondary battery BT by the characteristic acquisition unit 10, and determines the current value of the charging current I _CHG using the battery-side initial information by the charging current determination unit 30. . For this reason, even if it does not change a controller when changing the kind of secondary battery to charge, charge according to the characteristic of a secondary battery can be performed. Therefore, it is possible to support charging of various types of secondary batteries without manufacturing or changing a controller according to the type of secondary battery, and the charging system AA can be simplified.

Moreover, the charging device 1 determines the current value of the charging current I _CHG according to the charging voltage V _BT of the secondary battery BT by calculation in real time. For this reason, the current value of the charging current I _CHG can follow the change in the charging voltage V _BT of the secondary battery BT in real time. Therefore, compared with the charging device shown in Patent Document 1, it is possible to shorten the time until the secondary battery BT becomes fully charged.

In addition, the charging device 1 uses the charging current determination unit 30 to calculate the first charging current calculation formula shown in Formula (1), the second charging current calculation formula shown in Formula (4), and Formula (6). One of the third charging current calculation formulas shown in FIG. 5 is selected according to the battery side initial information, and the current value of the charging current I _CHG is determined using the selected formula. For this reason, by setting the above-described charging current calculation formula in consideration of the characteristics of various types of secondary batteries, it is possible to handle charging of various types of secondary batteries.

The charging device 1 is provided with a charging voltage detector 20 for detecting the charging voltage _{V BT} of the secondary battery BT. Therefore, means for detecting a charging voltage V _BT of the secondary battery BT is not be provided outside of the charging apparatus 1, it is possible to obtain the same effect as described above.

  The present invention is not limited to the above-described embodiment, and various modifications and applications can be made without departing from the gist of the present invention.

  For example, in the above-described embodiment, the battery-side initial information is acquired from the secondary battery BT, but is not limited thereto, and may be acquired from, for example, a peripheral circuit of the secondary battery BT.

In the above-described embodiment, the mathematical expression used when determining the current value of the charging current I _CHG is selected from the three charging current calculation expressions. However, the present invention is not limited to this. For example, two charging currents are used. It is good also as selecting from a calculation formula and five charge current calculation formulas. Further, only one charging current calculation formula is provided, and the current value of the charging current I _CHG may be determined using this charging current calculation formula.

In the above-described embodiment, a mathematical expression is used when determining the current value of the charging current I _CHG . However, the present invention is not limited to this, and for example, a LUT (Look Up Table) may be used. Specifically, a plurality of LUTs that store the relationship between the charging current and the charging voltage of the secondary battery are provided, one of the plurality of LUTs is selected according to the battery side initial information, and the selected LUT is used. The current value of the charging current I _CHG may be determined.

  In the above-described embodiment, the charging device 1 acquires the battery-side initial information shown in Table 2 as the characteristic of the secondary battery BT, but is not limited thereto. For example, it is possible to acquire the internal impedance, manufacturing date, manufacturer name, model name, manufacturing ID, and the like of the secondary battery BT and store them as data.

In the above-described embodiment, various types of secondary batteries such as lithium ion batteries and nickel metal hydride batteries can be used as the secondary battery BT. However, the lithium ion battery has a characteristic that a large current can flow during charging / discharging although the internal impedance is lower than that of the secondary battery other than the lithium ion battery. For this reason, the potential difference generated by the internal impedance during charging may be larger in the lithium ion battery than in the secondary battery other than the lithium ion battery due to Ohm's law. Therefore, in particular, in the lithium ion battery, it is preferable that the current value of the charge end current can be set small in order to obtain a fully charged state as compared with the secondary battery other than the lithium ion battery. Charging apparatus 1 acquires the battery side initial information shown in Table 2 from the secondary battery BT, and acquires the termination current value I ₁₂ is the current value of the optimal charging end current to the secondary battery BT. As described above, various types of secondary batteries can be used as the secondary battery BT as described above, and lithium ion batteries are particularly preferable.

DESCRIPTION OF SYMBOLS 1; Charging apparatus 10; Characteristic acquisition part 20; Charging voltage detection part 30; Charging current determination part 40; Charging current supply part AA; Charging system BT; Secondary battery

Claims (6)

A charging device for charging a secondary battery,
Characteristic acquisition means for acquiring characteristics of the secondary battery;
Charging current determining means for determining the current value of the charging current supplied to the secondary battery according to the charging voltage of the secondary battery using the characteristics of the secondary battery acquired by the characteristics acquiring means;
A charging apparatus comprising: charging current supply means for supplying a charging current having a current value determined by the charging current determination means to the secondary battery. The charging current determining means includes
A relationship acquisition procedure for obtaining a relationship between a charging current and a charging voltage of the secondary battery based on the characteristics of the secondary battery acquired by the characteristic acquisition means;
And performing a current value determination procedure for determining a current value of a charging current supplied to the secondary battery according to a charging voltage of the secondary battery, using the relationship obtained in the relationship acquisition procedure. The charging device according to claim 1. The charging current determining means includes
In the relationship acquisition procedure, on the basis of the characteristics of the secondary battery acquired by the characteristic acquisition means, a mathematical formula indicating the relationship between the charging current and the charging voltage of the secondary battery is determined,
In the current value determination procedure, the current value of the charging current supplied to the secondary battery is calculated according to the charging voltage of the secondary battery by calculating in real time using the formula determined in the relationship acquisition procedure. The charging device according to claim 2, wherein the charging device is determined. The charging current determining means includes
Storing a plurality of the mathematical formulas,
In the relationship acquisition procedure, one of the mathematical formulas is selected according to the characteristics of the secondary battery,
The charging device according to claim 3, wherein in the current value determination procedure, the mathematical formula selected in the relationship acquisition procedure is used for the calculation.   The charging device according to any one of claims 1 to 4, further comprising a charging voltage detection unit that detects a charging voltage of the secondary battery.   The charging device according to claim 1, wherein the secondary battery is a lithium ion battery.

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