JP-7855030-B2 - Charging system, battery pack

JP7855030B2JP 7855030 B2JP7855030 B2JP 7855030B2JP-7855030-B2

Inventors

堀智貴
加納隼人

Assignees

株式会社マキタ

Dates

Publication Date: 20260507
Application Date: 20240710

Claims (9)

A high-rate charger configured to connect to a battery pack containing a lithium-ion battery, A low-rate charger configured to be connected to the aforementioned battery pack, The maximum current that the aforementioned high-rate charger can output is equal to or greater than the completion current value. The maximum current that the low-rate charger can output is less than the completion current value. The aforementioned completion current value corresponds to the magnitude of the charging current at the completion of charging when the lithium-ion battery is charged at a constant current and constant voltage. The high-rate charger is configured to stop outputting the charging current when it is determined that the battery pack has met a first condition while charging the battery pack connected to the high-rate charger. The low-rate charger is configured to stop outputting the charging current when it is determined that a second condition, different from the first condition, has been met by the battery pack while the battery pack connected to the low-rate charger is being charged. Charging system.
The high-rate charger and the low-rate charger are charger control units, The maximum current value is calculated based on the charger's status. The charging current output to the battery pack has the smaller of the calculated upper limit current value and the requested current value corresponding to the magnitude of the charging current requested by the battery pack. A charger control unit is provided, configured as follows: The charging system according to claim 1.
The charger control unit, The charger is configured to acquire the temperature of the charger. The state of the charger is the temperature of the charger obtained by the charger control unit. The charging system according to claim 2.
A battery pack comprising a lithium-ion battery and a battery control unit, configured to be connected to a high-rate charger or low-rate charger of a charger system, The maximum current that the aforementioned high-rate charger can output is equal to or greater than the completion current value. The maximum current that the low-rate charger can output is less than the completion current value. The aforementioned completion current value corresponds to the magnitude of the charging current at the completion of charging when the lithium-ion battery is charged at a constant current and constant voltage. The battery control unit, The voltage value of the lithium-ion battery is obtained, Obtain a charging current value corresponding to the magnitude of the charging current in the current processing cycle. Based on the acquired charging current value, a required current value corresponding to the magnitude of the charging current allowed in the next processing cycle is calculated. If the acquired charging current value is equal to or greater than the completion current value, the charging of the lithium-ion battery is stopped in accordance with the first condition being met. The system is configured to stop charging the lithium-ion battery when the charging current value obtained by the battery control unit is less than the completion current value, and the second condition is met. The first condition is met based on the fact that the voltage value obtained by the battery control unit is equal to or greater than the completion voltage value, and the requested current value calculated by the battery control unit is less than the completion current value. The second condition is different from the first condition. Battery pack.
The battery control unit is configured to output the calculated required current value to the high-rate charger or the low-rate charger connected to the battery pack. The battery pack according to claim 4.
The battery control unit is configured to calculate a target voltage value. The target voltage value corresponds to the open-circuit voltage of the lithium-ion battery when charging of the lithium-ion battery is stopped in accordance with the fulfillment of the first condition. The second condition is set such that the open-circuit voltage value when charging of the lithium-ion battery is stopped in accordance with the fulfillment of the second condition matches the target voltage value. The battery pack according to claim 4 or 5.
The battery control unit, The temperature of the lithium-ion battery is obtained, The system is configured to calculate the target voltage value based on the acquired temperature and/or the degree of degradation of the lithium-ion battery. The battery pack according to claim 6.
The second condition is met based on the fact that the voltage value obtained by the battery control unit is equal to or greater than the determination value. The determination value corresponds to the value obtained by adding a correction value to the target voltage value. The correction value corresponds to (Vset - Vtg) × Inow/Icut, where Vset corresponds to the completion voltage value, Vtg corresponds to the target voltage value, Inow corresponds to the charging current value obtained by the battery control unit, and Icut corresponds to the completion current value. The battery pack according to claim 6 or 7.
The battery control unit, The temperature of the lithium-ion battery is obtained, The system is configured to calculate the completion current value based on the acquired temperature and/or the degree of degradation of the lithium-ion battery. The battery pack according to any one of claims 4 to 8.

Description

This disclosure relates to a rechargeable battery pack. Patent Document 1 describes a relatively large, high-rate charger. Japanese Patent Publication No. 2019-80406 This figure shows the battery pack and high-rate charger of the charging system according to this embodiment.This figure shows the battery pack and low-rate charger of the charging system according to this embodiment.This figure shows the electrical configuration of the charging system according to this embodiment.This shows the time variation of the battery voltage and charging current when charging is terminated in accordance with the first condition being met by a charger whose maximum output current value is equal to or greater than the completion current value.This shows the time variation of the battery voltage and charging current when charging is terminated in accordance with the first condition being met by a charger whose maximum output current value is less than the completion current value.This shows the time variation of the battery voltage and charging current when charging is terminated in accordance with the second condition being met by a charger whose maximum output current value is less than the completion current value.This flowchart shows the charging control process performed by the battery pack and the high-rate or low-rate charger.This is a table showing target voltage values based on the degree of degradation and battery temperature. The following describes the implementation of this disclosure with reference to the drawings. <1. Structure> <1-1. System Configuration> The charging system 1 according to this embodiment will be described with reference to Figures 1 and 2. The charging system 1 according to this embodiment comprises a battery pack 100, a high-rate charger 200, and a low-rate charger 300. The battery pack 100 includes a rechargeable battery 30, which will be described later. The battery 30 is, for example, a lithium-ion battery, which includes a plurality of battery cells connected in series. The battery pack 100 includes a battery-side mounting portion 20 and a battery-side terminal portion 10. The battery-side mounting section 20 is provided on the lower surface of the battery pack 100 and is configured to be mounted on a high-rate charger 200 and a low-rate charger 300. The battery-side terminal section 10 is provided on the battery-side mounting section 20 and has a plurality of terminals, which will be described later. The battery-side mounting section 20 is also configured to be mounted on an electric work machine (not shown). When the battery-side mounting section 20 is mounted on an electric work machine, the battery pack 100 supplies power to the electric work machine, and the electric work machine is driven by the power received from the battery pack 100. Electric work machines include power tools such as impact drivers and circular saws, gardening tools such as brush cutters and trimmers, laser levels, lights, etc. The high-rate charger 200 and the low-rate charger 300 are equipped with power cords, which are connected to an external power source such as a commercial power supply. The high-rate charger 200 and the low-rate charger 300 generate power to supply to the battery 30 from the power supplied from the external power source. The high-rate charger 200 is a charger that charges the battery 30 at a high rate. The maximum output current value of the high-rate charger 200 is equal to or greater than the completion current value Icut, and the high-rate charger 200 can charge the battery pack 100 with a current equal to or greater than the completion current value Icut. The completion current value Icut corresponds to the charging current value at the completion of charging when the battery 30 is charged with constant current and constant voltage. The low-rate charger 300 is a charger that charges the battery 30 at a low rate. The maximum output current value of the low-rate charger 300 is less than the completion current value Icut, and the low-rate charger 300 can only charge the battery pack 100 with a current value less than the completion current value Icut. The high-rate charger 200 comprises a charger-side mounting portion 220 and a charger-side terminal portion 210. The charger-side mounting portion 220 is provided on the upper surface of the high-rate charger 200, and the charger-side terminal portion 210 is provided on the charger-side mounting portion 220. The low-rate charger 300 comprises a charger-side mounting portion 320 and a charger-side terminal portion 310. The charger-side mounting portion 320 is provided on the upper surface of the low-rate charger 300, and the charger-side terminal portion 310 is provided on the charger-side mounting portion 320. The charger-side mounting portion 220 is configured to have the same shape as the charger-side mounting portion 320. The charger-side terminal portion 210 and the charger-side terminal portion 310 are equipped with multiple termina