Abstract: Cooling air intake port (52), cooling air exhaust port (55), and securing walls (86, 87), which contact and secure the side surfaces of one or more battery cells (72), may be defined within two battery pack housing halves (50, 80). When battery pack (99) is assembled, at least one cooling air passage (91, 92) is defined by the side surfaces of the battery cells, the interior surface of the battery pack housing, and the securing walls. The cooling air passage connects the cooling air intake port to the cooling air exhaust port. Further, the securing walls isolate or physically separate the cooling air passage from battery terminals (72a, 72b). By forcing cooling air through the cooling air passage, the battery cells can be effectively and efficiently cooled.

Abstract: Cooling air intake port (52), cooling air exhaust port (55), and securing walls (86, 87), which contact and secure the side surfaces of one or more battery cells (72), may be defined within two battery pack housing halves (50, 80). When battery pack (99) is assembled, at least one cooling air passage (91, 92) is defined by the side surfaces of the battery cells, the interior surface of the battery pack housing, and the securing walls. The cooling air passage connects the cooling air intake port to the cooling air exhaust port. Further, the securing walls isolate or physically separate the cooling air passage from battery terminals (72a, 72b). By forcing cooling air through the cooling air passage, the battery cells can be effectively and efficiently cooled.

Abstract: A system for charging a power tool battery includes a charging device capable of charging a battery, a memory device capable of storing data of a plurality of sound patterns, a selecting device capable of selecting a sound pattern data from the plurality of sound patterns, and a sound generating device capable of generating a sound based on the selected sound pattern data when the charging operation of the battery by the charging device has been completed.

Abstract: A diagnostic technique for determining whether the degradation of a rechargeable battery is normal or abnormal is provided. A device for determining whether the degradation of a rechargeable battery is normal or abnormal comprises a device for measuring a degradation indicator of a rechargeable battery, a device for determining the usage quantity of the rechargeable battery, and a device for comparing the usage quantity with a reference usage quantity in the case where the measured degradation indicator exceeds a reference degradation value.

Abstract: Cooling air intake port (52), cooling air exhaust port (55), and securing walls (86, 87), which contact and secure the side surfaces of one or more battery cells (72), may be defined within two battery pack housing halves (50, 80). When battery pack (99) is assembled, at least one cooling air passage (91, 92) is defined by the side surfaces of the battery cells, the interior surface of the battery pack housing, and the securing walls. The cooling air passage connects the cooling air intake port to the cooling air exhaust port. Further, the securing walls isolate or physically separate the cooling air passage from battery terminals (72a, 72b). By forcing cooling air through the cooling air passage, the battery cells can be effectively and efficiently cooled.

Abstract: Cooling air intake port (52), cooling air exhaust port (55), and securing walls (86, 87), which contact and secure the side surfaces of one or more battery cells (72), may be defined within two battery pack housing halves (50, 80). When battery pack (99) is assembled, at least one cooling air passage (91, 92) is defined by the side surfaces of the battery cells, the interior surface of the battery pack housing, and the securing walls. The cooling air passage connects the cooling air intake port to the cooling air exhaust port. Further, the securing walls isolate or physically separate the cooling air passage from battery terminals (72a, 72b). By forcing cooling air through the cooling air passage, the battery cells can be effectively and efficiently cooled.

Abstract: A diagnostic technique for determining whether the degradation of a rechargeable battery is normal or abnormal is provided. A device for determining whether the degradation of a rechargeable battery is normal or abnormal comprises a device for measuring a degradation indicator of a rechargeable battery 18, a device for determining the usage quantity of the rechargeable battery, and a device for comparing the usage quantity with a reference usage quantity in the case where the measured degradation indicator exceeds a reference degradation value.

Abstract: A battery pack (1) has a double casing structure, including an inner case (2) disposed inside an outer case (3). The inner case (2) includes a radiator plate (9) that is in contact with the side walls of battery cells (4) disposed within the battery pack (1). A forked air passage (32) extends from an air inlet (27) and is defined between the inner case (2) and the outer case (3) and along the outer surface of the radiator plate (9) until reaching a pair of air outlets (31).

Abstract: Object of the invention is to provide an improved technique of suitably charging a battery assembly irrespective of the kind of the battery assembly. The representative battery charger 100 includes a power supply section 110, a detecting section 130 that detects voltage that represents a temperature index of the battery assembly 200, 300 a reference voltage that is compared with the detected temperature-representing voltage of the battery assembly. The battery charger 100 stops supplying the charging current when the temperature-representing voltage of the battery assembly reaches or exceeds the reference voltage. The reference voltage varies according to the charging voltage of the battery assembly and thus, the threshold temperature to complete the charge can be varied according to the charging voltage of the battery assembly 200, 300. As a result, an overload state for the battery assembly with high charging voltage and high temperature can effectively be prevented.

Abstract: Battery pack (50) may include rechargeable batteries (55) and first temperature sensor TM1 for detecting the temperature of batteries (55). Battery charger (10) may include power source circuit (32) for supplying charging current to batteries (55) of battery pack (50). Battery charger (10) may also include second temperature sensor TM2 located in the vicinity of power source circuit (32). Battery charger (10) may further include a processor for controlling power source circuit (32). The processor may select charging current that will be supplied by power source circuit (32) to batteries (55) based at least upon battery temperature from first temperature sensor TM1 and power source circuit temperature from second temperature sensor TM2, and supply the selected charging current to batteries (55).

Abstract: Battery pack 10 may include rechargeable battery 12 and remaining capacity indicating circuit 14 for indicating the remaining capacity of the battery 12. Remaining capacity indicating circuit 14 may be coupled to the battery 12 via first switch SW1. When first switch SW1 is turned ON, a current flows from battery 12 to remaining capacity indicating circuit 14. When the first switch SW1 is turned OFF, the current flowing from battery 12 to remaining capacity indicating circuit 14 is turned OFF. The first switch SW1 may be coupled to first voltage detecting circuit (R2, R3) for detecting the voltage of battery 12. When the voltage that is being detected of battery 12 falls below a first predetermined value, first switch SW1 is turned off. Battery pack 10 may further include cut-off circuit (SW2, R4, R5) that cuts off the flow of current from battery 12 to first voltage detecting circuit (R2, R3) when first switch SW1 has been turned OFF.

Abstract: It is an object of the invention to provide an effective technique for reducing the load of user's fingers in a power tool. A representative power includes a body, a tool bit, a driving means and a handgrip that extends from a grip proximal end on the side of the body to a grip distal end in a direction that crosses the axial direction of the tool bit. The power tool includes a holding optimization region that is arranged on the handgrip and shaped to match with the holding form of the fingers of the user when the user holds the handgrip. Specifically, the holding optimization region at least includes the rear end surface of the grip distal end region such that a normal on the rear end surface crosses an axis of the tool bit forward of the handgrip. As a result, according to the invention, the force of the user's fingers and palm on the handgrip can be optimized.

Abstract: A plurality of charging devices 30 may be connected to a computer 10, 110 via a network 60. When computer 10 receives chewing information from a charging device 30 before performing a charging operation, computer 10 may compute the optimal charging period based upon the charging information. Parameters defining the optimal charging period may be transmitted to the respective charging devices 30. Each charging device 30 may perform the battery charging operation based upon the transmitted parameters. Thus, a network system can manage and control the charging operations for the plurality of charging devices in order to optimize charging period, optimize the number of charging devices 30 and battery packs 50 in use and maximize battery life.

Abstract: Battery charger (10) may include a power source circuit (22) for charging rechargeable batteries (58) when a battery pack (50) is connected directly to the battery charger or is connected thereto with an adapter (30) interposed therebetween. The adapter may include a discharging circuit (42) for discharging the rechargeable batteries. The adapter may also include a switch (48) 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 (61) storing a flag indicating whether a refresh process is required. The adapter may further include a control portion (41) 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.

Abstract: It is an object of the invention to provide a technique for coping with the difference of self-discharge between battery groups that form a battery assembly. According to the invention, a battery assembly that includes a plurality of battery groups and feeder is provided. Battery groups may include at least first and second battery groups and each battery group is defined by one or more cells. The feeder may feed electricity from the first battery group to the second battery group based on a difference in residual capacity caused by a difference of self-discharge amount between the first battery group and the second battery group. According to the invention, because difference in residual capacity between the respective battery groups can be balanced, even if the battery assembly is recharged in the state in which the battery groups have some residual capacities, overcharge and insufficient charge can be alleviated.

Abstract: A diagnostic technique for determining whether the degradation of a rechargeable battery is normal or abnormal is provided. A device for determining whether the degradation of a rechargeable battery is normal or abnormal comprises a device for measuring a degradation indicator of a rechargeable battery 18, a device for determining the usage quantity of the rechargeable battery, and a device for comparing the usage quantity with a reference usage quantity in the case where the measured degradation indicator exceeds a reference degradation value.

Abstract: Battery pack 10 may include rechargeable battery 12 and remaining capacity indicating circuit 14 for indicating the remaining capacity of the battery 12. Remaining capacity indicating circuit 14 may be coupled to the battery 12 via first switch SW1. When first switch SW1 is turned ON, a current flows from battery 12 to remaining capacity indicating circuit 14. When the first switch SW1 is turned OFF, the current flowing from battery 12 to remaining capacity indicating circuit 14 is turned OFF. The first switch SW1 may be coupled to first voltage detecting circuit (R2, R3) for detecting the voltage of battery 12. When the voltage that is being detected of battery 12 falls below a first predetermined value, first switch SW1 is turned off. Battery pack 10 may further include cut-off circuit (SW2, R4, R5) that cuts off the flow of current from battery 12 to first voltage detecting circuit (R2, R3) when first switch SW1 has been turned OFF.

Abstract: A battery pack (1) includes an outer enclosure (2) and a forked air passage (72) for introducing cooling air via the intake port (9) formed in an outer enclosure (2), sending the air between cell groups (70) and (71) which contain cells (14a-14f), and discharging it from the outer enclosure at discharge ports (11). Two metallic radiator plates (73) partially define the air passage so as to be in contact with the side cells (14a-14d), whereas a circular radiator plate (74) made of synthetic resin also partially define the air passage so as to be in contact with the center cells (14e, 14f). The contact areas of the side cells with the metallic radiator plates (73) are varied in order to achieve even cooling of the cells. The upstream portion of the synthetic resin radiator plate has a thicker wall than the downstream portion to achieve the same purpose.

Abstract: Battery pack (50) may include rechargeable batteries (55) and first temperature sensor TM1 for detecting the temperature of batteries (55). Battery charger (10) may include power source circuit (32) for supplying charging current to batteries (55) of battery pack (50). Battery charger (10) may also include second temperature sensor TM2 located in the vicinity of power source circuit (32). Battery charger (10) may further include a processor for controlling power source circuit (32). The processor may select charging current that will be supplied by power source circuit (32) to batteries (55) based at least upon battery temperature from first temperature sensor TM1 and power source circuit temperature from second temperature sensor TM2, and supply the selected charging current to batteries (55).

Abstract: A temperature rise pattern is retrieved from charging time based on the difference between a battery temperature at the beginning of battery charge and a target temperature value which a battery is intended to reach (in S116). The battery is charged while adjusting a current value so that a temperature rise value becomes the temperature rise pattern (in S118 and S120). Thus, by optimizing the temperature rise pattern, it is possible to charge the battery so that the temperature at the time of the completion of battery charge becomes the target temperature value (the lowest temperature value).