Makita Corporation

Tomoo Muramatsu

Hitoshi Suzuki

Tadahiko Kobayakawa

Kazuyuki Sakakibara

Hisakazu Okabayashi

Junichi Katayama

Yasuhiro Tabuchi

A battery pack in one aspect of the present disclosure includes a rechargeable battery, a rewritable nonvolatile memory, a write request receiver, and a write controller. The rewritable nonvolatile memory includes storage areas including a write-inhibit area. The write request receiver receives a write request and data from a charger. The write request includes a first address assigned to a first storage area of the storage areas. The data includes a first data element. The write controller executes a write process for the received data. The write process includes avoiding writing the first data element to the first storage area in response to determining that the first storage area is the write-inhibit area.

Battery pack and method for writing data to battery pack

A charger of the present invention includes a plurality of battery connection parts to which battery packs can be connected to charge, with each battery connection part having an indicator. The indicators can be configured such that when charging is expected to be completed more quickly in a first battery connection part compared to a second battery connection part, the indicator of the first battery connection part is displayed differently from the indicator of the second battery connection part.

Charger

A battery pack for power tool includes a battery, a monitoring circuit, and a sleep mode switching unit. The battery includes at least one battery cell. The monitoring circuit is operated by receiving power supply from the battery. The sleep mode switching unit switches the battery pack to a sleep mode by stopping at least a part or all of operations of the monitoring circuit when the monitoring circuit detects a discharge end state where a discharge current from the battery is equal to or lower than a predetermined set current value, and the monitoring circuit further detects at least one of a voltage stable state where a voltage change amount in the battery cell is within a predetermined stable range of voltage change amount and a temperature stable state where a temperature change amount in the battery is within a predetermined stable range of temperature change amount.

Battery pack for power tool, and power tool

A battery monitoring system for electric power tool includes a battery pack for electric power tool and an auxiliary power source. The battery pack has a battery and a monitoring circuit. The battery is provided with at least one battery cell. The monitoring circuit is operated by electric power supplied from the battery, and monitors a status of the battery. The auxiliary power source outputs electric power allowing the monitoring circuit to operate. The monitoring circuit is configured such that, when the monitoring circuit is unoperational with the electric power of the battery due to a decrease in a voltage of the battery, the monitoring circuit becomes operational by the electric power supplied from the auxiliary power source.

Monitoring system for electric power tool, battery pack for electric power tool, and battery charger for electric power tool

Each of a battery charger and a battery pack has a microcomputer. The respective microcomputers mutually perform data communication while the battery pack is being charged by the battery charger, and confirm an operational state of the microcomputer of the communication counterpart (mutual operation confirmation) based on a result of the data communication. When an abnormality of one of the microcomputers is detected, the other microcomputer executes a predetermined process for stopping charging.

Charging system for electric power tool, battery pack for electric power tool, and battery charger for electric power tool

An electric power tool includes a tool body and a battery pack. A terminal voltage setting unit of the tool body sets a voltage of a body side terminal to a first voltage when a command to drive a drive portion of the tool body is issued by a switch of the tool body. A voltage changing unit of the battery pack changes a voltage of a battery side terminal from the first voltage to a second voltage when supply of electric power from the battery pack to the drive portion is permitted.

Electric power tool, tool body, and battery pack

Battery charger () may include a power source circuit () for charging rechargeable batteries () when a battery pack () is connected directly to the battery charger or is connected thereto with an adapter () interposed therebetween. The adapter may include a discharging circuit () for discharging the rechargeable batteries. The adapter may also include a switch () for alternatively connecting the rechargeable batteries with the discharging circuit or the charging circuit of the battery charger. The battery pack may have a memory () storing a flag indicating whether a refresh process is required. The adapter may further include a control portion () for controlling the switch. When the battery pack has been connected to the battery charger via the adapter, the control portion may preferably controls the switch on the basis of the flag stored in the memory of the battery pack.

Apparatus for refreshing batteries

A map is retrieved based on a battery temperature, a temperature rise value and an allowable current value, with which a battery can be charged while battery temperature rise is being suppressed, is obtained and the battery is charged with the allowable current value. By doing so, it is possible to charge a nickel metal hydride battery cell which temperature tends to rise during battery charge in a short time without causing deterioration due to temperature rise. This battery charger makes determinations after dividing the battery. Due to this, compared with a case of simultaneously determining all battery cells, it is possible to accurately determine the completion of charge.

Growing community of inventors

Anjo, Japan

Tomoo Muramatsu