Patent ID: 11894710
Assignee: MAKITA CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
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 Ic1, the upper limit current value Ic1 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 Ic1, and
setting the upper limit current value Ic1 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 Ic1.