US 6,204,639 B1Granted

Battery charger determining charging conditions depending upon whether a cooling device is provided

AssigneeHitachi Koki Co., Ltd.

InventorsNobuhiro Takano, Yoshio Iimura, Yukihiro Shima, Kenrou Ishimaru

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Abstract

To provide inexpensive and economic battery chargers with excellent productivity, a control circuit board for the battery charger is produced so as to be usable in common for both the battery chargers with a cooling device and the battery chargers without a cooling device. In the control circuit board, a cooling device detection circuit is provided for detecting whether or not the cooling device is provided. An average charge current to be applied to a battery pack to be charged is controlled depending on whether or not the cooling device is provided. The average charge current is further controlled depending on the type of the battery pack, i.e., whether it is of a small rated capacity or of a large rated capacity, and on a rate of change in battery temperature at the time of start of charging.

Claims16

Dependent claims

A battery charger comprising:

a microcomputer;
a charge current supplying section for supplying a charge current to a battery pack to be charged:
a connector to which a cooling device is optionally connectable, said cooling device operating to cool said battery pack;
a cooling device detection circuit operatively connected to said microcomputer and said connector, said cooling device detection circuit detecting whether or not said cooling device is connected to said connector and outputting a first signal to said microcomputer when said cooling device is connected to said connector and a second signal to said microcomputer when said cooling device is not connected to said connector;
and
a charge current control section operatively connected to said microcomputer and said charge current supplying section, said microcomputer instructing said charge current control section to control an average charge current to be applied to said battery pack during charging of said battery pack in response to outputs from said cooling device detection circuit.

3 more elements

A battery charger comprising:

a microcomputer;
a charge current supplying section for supplying a charge current to a battery pack to be charged, said battery pack optionally including a cooling device for cooling a plurality of chargeable cells connected in series and contained in said battery pack;
a cooling device detection circuit operatively connected to said microcomputer for detecting whether or not said cooling device is included in said battery pack, said cooling device detection circuit outputting a first signal to said microcomputer when said cooling device is included in said battery pack and a second signal to said microcomputer when said cooling device is not included in said battery pack;
and
a charge current control section operatively connected to said microcomputer and said charge current supplying section, said microcomputer instructing said charge current control section to control an average charge current to be applied to said battery pack during charging of said battery pack in response to outputs from said cooling device detection circuit.

2 more elements

Dependencies are inferred from the claim text.