Abstract: A battery pack may include a drainage device provided at a bottom portion of the housing case. The drainage device may include a drain hole communicating between the inside and the outside of the housing case, so that water introduced into the housing case is discharged to the outside of the housing case. The drainage device may be disposed between two of the terminal members that are connected to electrodes of the battery cells.

Abstract: A battery pack may include a drainage device provided at a bottom portion of the housing case. The drainage device may include a drain hole communicating between the inside and the outside of the housing case, so that water introduced into the housing case is discharged to the outside of the housing case. The drainage device may be disposed between two of the terminal members that are connected to electrodes of the battery cells.

Abstract: A battery pack may include a drainage device provided at a bottom portion of the housing case. The drainage device may include a drain hole communicating between the inside and the outside of the housing case, so that water introduced into the housing case is discharged to the outside of the housing case. The drainage device may be disposed between two of the terminal members that are connected to electrodes of the battery cells.

Abstract: One aspect according to the present invention includes a battery pack and a shock absorbing device interposed between a battery cell holder and a case body and capable of keeping the battery cell holder and the battery cells not to directly contact with an inner surface of the case body.

Abstract: A battery pack may include a drainage device provided at a bottom portion of the housing case. The drainage device may include a drain hole communicating between the inside and the outside of the housing case, so that water introduced into the housing case is discharged to the outside of the housing case. The drainage device may be disposed between two of the terminal members that are connected to electrodes of the battery cells.

Abstract: A battery pack may include a drainage device provided at a bottom portion of the housing case. The drainage device may include a drain hole communicating between the inside and the outside of the housing case, so that water introduced into the housing case is discharged to the outside of the housing case. The drainage device may be disposed between two of the terminal members that are connected to electrodes of the battery cells.

Abstract: A battery pack may include a drainage device provided at a bottom portion of the housing case. The drainage device may include a drain hole communicating between the inside and the outside of the housing case, so that water introduced into the housing case is discharged to the outside of the housing case. The drainage device may be disposed between two of the terminal members that are connected to electrodes of the battery cells.

Abstract: A battery pack may include a drainage device provided at a bottom portion of the housing case. The drainage device may include a drain hole communicating between the inside and the outside of the housing case, so that water introduced into the housing case is discharged to the outside of the housing case. The drainage device may be disposed between two of the terminal members that are connected to electrodes of the battery cells.

Abstract: One aspect according to the present invention includes a battery pack and a shock absorbing device interposed between a battery cell holder and a case body and capable of keeping the battery cell holder and the battery cells not to directly contact with an inner surface of the case body.

Abstract: One aspect according to the present invention includes a battery pack and a shock absorbing device interposed between a battery cell holder and a case body and capable of keeping the battery cell holder and the battery cells not to directly contact with an inner surface of the case body.

Abstract: One aspect according to the present invention includes a battery pack and a shock absorbing device interposed between a battery cell holder and a case body and capable of keeping the battery cell holder and the battery cells not to directly contact with an inner surface of the case body.

Abstract: One aspect according to the present invention includes a battery pack and a shock absorbing device interposed between a battery cell holder and a case body and capable of keeping the battery cell holder and the battery cells not to directly contact with an inner surface of the case body.

Abstract: An electric tool main body of an electric tool includes a battery retaining portion, and a battery includes a fitting portion capable of fitting with the battery retaining portion; the battery is connected to the electric tool main body through a sliding motion in a predetermined direction with respect to the electric tool main body in the state that the battery retaining portion is fitted with the fitting portion; the electric tool main body includes a connection prohibition portion prohibiting connection of other battery than the dedicated battery even if the battery is compatible with the rated voltage of the electric tool main body.

Abstract: A battery pack includes a circuit board and a battery cell group disposed within a battery case. The battery cell group includes a plurality of cylindrical battery cells staggered from each other so that the battery cell group includes at least a first battery cell stage and a second battery cell stage. The first battery cell stage is positioned on the side of the circuit board. The second battery cell stage is positioned adjacent to the first stage on the side away from the circuit board. The first battery cell stage includes a first battery cell and a second battery cell positioned at opposite ends of the first battery cell stage and a central battery cell positioned between the first and the second battery cell. The central battery cell is spaced from the circuit board by a distance, so that the central battery cell does not interfere with the circuit elements of the circuit board.

Abstract: One aspect according to the present invention includes a battery pack and a shock absorbing device interposed between a battery cell holder and a case body and capable of keeping the battery cell holder and the battery cells not to directly contact with an inner surface of the case body.

Abstract: One aspect according to the present invention includes a battery pack having a battery pack body. The battery pack body includes a finger engaging portion engageable with a finger or fingers of an operator in a removing direction of the battery pack body from a power tool.

Abstract: A plasma potential measuring method is conducted by: providing a measurement space surrounded by a radio-frequency electric field in plasma atmosphere; varying a floating potential at an electrode located in the measurement space by the ponderomotive effect acted only on electrons; and determining as a plasma potential a value of the floating potential at the time when an ion current flown into the electrode begins to lower.

Abstract: A plasma potential measuring method is conducted by: providing a measurement space surrounded by a radio-frequency electric field in plasma atmosphere; varying a floating potential at an electrode located in the measurement space by the ponderomotive effect acted only on electrons; and determining as a plasma potential a value of the floating potential at the time when an ion current flown into the electrode begins to lower.

Abstract: To inform a user of wear on a carbon brush for a motor earlier than when the carbon brush is actually required to be replaced with a new brush. In a motor brush wear indicating device, a metal terminal is attached to a brush holder, being opposed to the inside of a holder shank of the brush holder, and an indicator is operated when the metal terminal contacts a brush spring. The metal terminal has a contact in the middle of a length of the brush holder. The indicator can be operated while the carbon brush is continuously pressed against a commutator by the brush spring. The metal terminal serves as a leaf spring. When the carbon brush is worn and shortened, the indicator is operated. Even after the indicator operates, the carbon brush is still pressed against the commutator by the brush spring. Therefore, the user can operate a motor-driven tool for some time before the carbon brush must be replaced with a new one.