Battery pack, charging system, and method for controlling charging of battery pack

Patent metadata

Field	Value
Publication number	US-11894710-B2
Application number	US-202017011347-A
Country	US
Kind code	B2
Filing date	Sep 3, 2020
Priority date	Sep 6, 2019
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

A battery pack in one aspect of the present disclosure includes a first cell, a memory device, a target current calculator, and an information notifier. The memory device stores a maximum variation of a charging current value. The maximum variation is determined depending on a characteristic of the battery pack. The target current calculator calculates a newest value of a target current value based on (i) a previous value of the target current value and (ii) the maximum variation. The information notifier transmits a charge condition information including the newest value.

First claim

What is claimed is:

1. A charging system, comprising:
a battery pack including:
a battery configured to be charged with a charging current supplied from a charger, the battery including cells;
a memory device configured to store a maximum variation ΔIbat of a charging current value Inow, the charging current value Inow corresponding to a magnitude of the charging current, the maximum variation ΔIbat being determined depending on (i) a magnitude of an impedance of each of the cells and (ii) a configuration of the battery; and
a Micro Processing Unit (MPU) configured to perform a charge condition setting process, the charge condition setting process including:
acquiring charging operation information from the charger, the charging operation information relating to an operation required for the charger to charge the battery, the charging operation information including the charging current value Inow,
determining whether a cell voltage value Vnow is larger than or equal to a target voltage value CV, the cell voltage value Vnow corresponding to a magnitude of a voltage of each of the cells, and the target voltage value CV corresponding to the magnitude of the voltage of each of the cells required for the charger to charge the battery,
determining whether a provisional current value (Inow+ΔIbat) is larger than a reference current value Iset, the provisional current value (Inow+ΔIbat) corresponding to a sum of (i) the charging current value Inow included in the charging operation information and (ii) the maximum variation ΔIbat, the reference current value Iset corresponding to an upper limit of the charging current value Inow permissible in the battery,
calculating a target current value Inext by adding the maximum variation ΔIbat to the charging current value Inow included in the charging operation information, in response to (i) the cell voltage value Vnow being determined to be smaller than the target voltage value CV and (ii) the provisional current value (Inow+ΔIbat) being determined to be smaller than or equal to the reference current value Iset, the target current value Inext corresponding to the magnitude of the charging current required to charge the battery,
setting the reference current value Iset as the target current value Inext in response to (i) the cell voltage value Vnow being determined to be smaller than the target voltage value CV and (ii) the provisional current value (Inow+ΔIbat) being determined to be larger than the reference current value Iset,
calculating the target current value Inext by subtracting the maximum variation ΔIbat from the charging current value Inow included in the charging operation information, in response to the cell voltage value Vnow being determined to be larger than or equal to the target voltage value CV, and
transmitting, to the charger, charge condition information including the target current value Inext; and

the charger including:
a charger-side power-supply circuit configured to supply the charging current to the battery pack; and
a charger-side Micro Processing Unit (MPU) configured to perform a charge control process, the charge control process including:
acquiring the charge condition information from the battery pack,
determining whether the target current value Inext included in the charge condition information is larger than an upper limit current value Ic 1 , the upper limit current value Ic 1 corresponding to an upper limit of the charging current value Inow determined according to a temperature of the charger,
setting the target current value Inext included in the charge condition information as the magnitude of the charging current, in response to the target current value Inext included in the charge condition information being determined to be smaller than or equal to the upper limit current value Ic 1 , and
setting the upper limit current value Ic 1 as the magnitude of the charging current, in response to the target current value Inext included in the charge condition information being determined to be larger than the upper limit current value Ic 1 .

2. A battery pack, comprising:
a first cell configured to be charged with a charging current supplied from a charger;
a memory device configured to store a maximum variation of a charging current value, the charging current value indicating a magnitude of the charging current output from the charger to the battery pack, the maximum variation being determined depending on a characteristic of the battery pack;
a target current calculator configured to calculate a newest value of a target current value based on (i) a previous value of the target current value and (ii) the maximum variation, the target current value corresponding to the magnitude of the charging current required to charge the first cell;
an information notifier configured to transmit charge condition information to the charger, the charge condition information including the newest value; and
an operation information acquirer configured to acquire charging operation information from the charger via communication with the charger, the charging operation information including the charging current value.

3. The battery pack according to claim 2 ,
wherein the characteristic of the battery pack includes at least a magnitude of an impedance of the first cell.

4. The battery pack according to claim 2 , further comprising:
a second cell configured to be charged with the charging current.

5. The battery pack according to claim 4 ,
wherein the first cell is connected in parallel with the second cell.

6. The battery pack according to claim 4 ,
wherein the characteristic of the battery pack depends on at least an arrangement of the first cell and the second cell.

7. The battery pack according to claim 2 ,
wherein the target current calculator is configured to set the charging current value included in the charging operation information as the previous value in order to calculate the newest value.

8. The battery pack according to claim 2 , further comprising:
a voltage comparator configured to determine whether a cell voltage value is smaller than a target voltage value, the cell voltage value corresponding to a magnitude of a voltage of the first cell, and the target voltage value corresponding to the magnitude of the voltage of the first cell required for the charger to charge the first cell,
wherein the target current calculator is configured to calculate the newest value by adding the maximum variation to the previous value, in response to the voltage comparator determining that the cell voltage value is smaller than the target voltage value.

9. The battery pack according to claim 8 ,
wherein the target current calculator is configured to calculate the newest value by subtracting the maximum variation from the previous value, in response to the voltage comparator determining that the cell voltage value is larger than or equal to the target voltage value.

10. A battery pack, comprising:
a first cell configured to be charged with a charging current supplied from a charger;
a memory device configured to store a maximum variation of a charging current value, the charging current value corresponding to a magnitude of the charging current, the maximum variation being determined depending on a characteristic of the battery pack;
a target current calculator configured to calculate a newest value of a target current value based on (i) a previous value of the target current value and (ii) the maximum variation, the target current value corresponding to the magnitude of the charging current required to charge the first cell;
an information notifier configured to transmit charge condition information to the charger, the c

Assignees

• Makita Corp

Inventors

• Uesugi Hiroki

Classifications

• H02J7/96

  in response to battery voltage · CPC title

• H02J7/953 Primary

  in response to charge current gradient · CPC title

• H02J7/975

  in response to temperature · CPC title

• H02J7/94

  in response to battery current · CPC title

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title