Battery charger having angled wall in battery receiving opening, and battery pack charging system and cordless power tool system including same

1. A charger for charging a battery pack that is detachably attachable to a cordless power tool, the charger comprising:

at least a first side wall that at least partially defines a battery pack receiving hole shaped to receive and accommodate the battery pack, and

a charging output element adapted to supply charging power to the battery pack,

wherein the battery pack receiving hole has a lateral cross sectional area that decreases downwardly in the vertical direction of the battery pack receiving hole such that gravity will cause the battery pack to be guided to a prescribed position within the battery pack receiving hole,

the charging output element is positioned so as to be proximal to a corresponding charging power input element of the battery pack when the battery pack is disposed in the prescribed position,

the battery pack receiving hole comprises a bottom part that is adapted to support a lowermost portion of the battery pack when the battery pack is disposed in the prescribed position, and

at least one opening is defined in the bottom part at a location that is lower in the vertical direction than the charging output element.

2. The charger according to claim 1 , wherein the charging output element is disposed on or in the first side wall, which is oriented so as to contact a surface of the battery pack when the battery pack is disposed in the prescribed position.

3. The charger according to claim 2 , wherein the first side wall is inclined relative to the vertical direction.

4. The charger according to claim 3 , wherein the first side wall is inclined relative to the vertical direction by an angle of inclination of between 10-70 degrees.

5. The charger according to claim 2 , wherein:

the bottom part is inclined downwardly in the vertical direction towards the first wall.

6. The charger according to claim 1 , further comprising:

a second side wall coupled to the first wall, and

a third side wall coupled to the first wall and facing the second side wall,

wherein at least one of the second and third side walls is inclined relative to the vertical direction such that the distance between the second and third inner walls decreases downwardly in the vertical direction.

7. The charger according to claim 6 ,

wherein both of the second and third side walls are inclined relative to the vertical direction by an angle of inclination of between 0.5-70 degrees.

8. The charger according to claim 1 , further comprising:

at least one first engaging part disposed on a first outer surface and

at least one second engaging part disposed on a second outer surface and being adapted to detachably engage at least one first engaging part of another charger in order to physically couple the two chargers together.

9. The charger according to claim 1 , further comprising:

at least one power output terminal disposed on a first outer surface and

at least one power input terminal disposed on a second outer surface and being adapted to electrically connect to at least one power output terminal of another charger in order to conduct current from one charger to the other charger.

10. The charger according to claim 1 , further comprising:

a current input receptacle disposed on a second outer surface at a location that will be covered by another charger when the charger is physically and electrically coupled to the other charger.

11. The charger according to claim 1 , wherein:

a second battery pack receiving hole is defined in the charger and is shaped to receive and accommodate a second battery pack, and

the charger is adapted to simultaneously charge two battery packs.

12. The charger according to claim 11 , wherein the charger is tray-shaped and further comprises at least one carrying handle.

13. The charger according to claim 1 , wherein the charging output element is adapted to wirelessly transmit charging power to the battery pack.

14. The charger according to claim 13 , wherein the charging output element comprises at least one induction coil.

15. The charger according to claim 1 , wherein the charging output element is adapted to conduct charging current to the battery pack via a wired connection.

16. A battery pack charging system, comprising:

the charger according to claim 1 , and

a battery pack adapted to be detachably attachable to a cordless power tool and having a charging input element adapted to receiving charging power from the charging output element of the charger.

17. The battery pack charging system according to claim 16 , wherein the charging input element comprises at least one induction coil.

18. A cordless power tool system, comprising:

the battery pack charging system according to claim 16 , and

a power tool adapted to be electrically driven by the battery pack.

19. The cordless power tool system according to claim 18 , further comprising:

a carrying case adapted to carry the power tool, the battery pack and the charger.

20. The cordless power tool system according to claim 19 , wherein the charger is adapted to be detachably engaged with at least one engaging part disposed inside of the carrying case.

21. The cordless power tool system according to claim 19 , wherein the charger is adapted to be detachably engaged with at least one engaging part disposed on an outer surface of the carrying case.

22. The cordless power tool system according to claim 18 , further comprising:

a power cord adapted to electrically connect the carrying case to another carrying case so that current is conducted from the carrying case to the other carrying case.

23. A charger for charging a battery pack that is detachably attachable to a cordless power tool, the charger comprising:

at least a first side wall that at least partially defines a battery pack receiving hole shaped to receive and accommodate the battery pack,

a second side wall coupled to the first wall,

a third side wall coupled to the first wall and facing the second side wall, and

a charging output element adapted to supply charging power to the battery pack,

wherein the battery pack receiving hole has a lateral cross sectional area that decreases downwardly in a vertical direction of the battery pack receiving hole such that gravity will cause the battery pack to be guided to a prescribed position within the battery pack receiving hole,

the charging output element is positioned so as to be proximal to a corresponding charging power input element of the battery pack when the battery pack is disposed in the prescribed position, and

both of the second and third side walls are inclined relative to the vertical direction by an angle of inclination such that the distance between the second and third inner walls decreases downwardly in the vertical direction.

24. The charger according to claim 23 , wherein the angle of inclination is between 0.5-70 degrees.

25. A cordless power tool system, comprising:

a charger for charging a battery pack that is detachably attachable to a cordless power tool, the charger comprising:

at least a first side wall that at least partially defines a battery pack receiving hole shaped to receive and accommodate the battery pack, and

a charging output element adapted to supply charging power to the battery pack,

wherein the battery pack receiving hole has a lateral cross sectional area that decreases downwardly in a vertical direction of the battery pack receiving hole such that gravity will cause the battery pack to be guided to a prescribed position within the battery pack receiving hole, and

the charging output element is positioned so as to be proximal to a corresponding charging power input element of the battery pack when the battery pack is disposed in the prescribed position;

a battery pack adapted to be detachably attachable to a cordless power tool and having a charging input element adapted to receiving charging power from the charging output element of the charger;

a power tool adapted to be electrically driven by the battery pack; and

a carrying case adapted to carry the power tool, the battery pack and the charger, wherein the charger is adapted to be detachably engaged with at least one engaging part disposed on an outer surface of the carrying case.