Mechanical foolproof design of battery charger and rechargeable battery

1. A battery charger comprising one or more slots, an individual slot being used for recharging a preselected-type battery after the preselected-type battery is accommodated into the individual slot, the preselected-type battery having a lateral surface and a front-end surface, an edge formed between the lateral and front-end surfaces being a beveled edge, an unaccepted-type battery being defined as the preselected-type battery with the lateral and front-end surfaces extended such that the beveled edge is replaced by a line edge, the individual slot comprising:

a cap formed with an interior channel used for receiving a front-end portion of the preselected-type battery, the cap comprising a stopping member, wherein the stopping member gradually narrows the channel along a battery-insertion direction for stopping the preselected-type battery and the unaccepted-type battery from further advancement into the channel while the beveled edge enables the preselected-type battery to go deeper into the channel than the unaccepted-type battery does to thereby enable the battery charger to distinguish the preselected-type battery from the unaccepted-type battery; and

a positive charging terminal for providing an external voltage to a positive electrode of the preselected-type battery to recharge the preselected-type battery, wherein the positive charging terminal is positioned in the channel to barely touch the positive electrode when the preselected-type battery is stopped by the stopping member such that while the preselected-type battery is allowed to be recharged, the positive charging terminal is disconnected from the unaccepted-type battery when the unaccepted-type battery is inserted into the channel, thereby avoiding the battery charger from accidentally recharging the unaccepted-type battery.

2. The battery charger of claim 1 , wherein the stopping member is shaped to complement the beveled edge such that the stopping member seamlessly receives the beveled edge when the preselected-type battery is inserted into the channel, whereby a mismatch between the stopping member and the line edge causes the stopping member to block the unaccepted-type battery from reaching deeper into the channel than the preselected-type battery does when the unaccepted-type battery is inserted into channel, causing the positive charging terminal to be disconnected from the unaccepted-type battery.

3. The battery charger of claim 1 , wherein the cap further comprises an interior wall defining the interior channel, and the stopping member is a portion of the interior wall.

4. The battery charger of claim 1 , wherein the cap further comprises an interior wall defining the interior channel, and a portion of the interior wall is shaped to complement the front-end surface such that the preselected-type battery is mated to the cap when the preselected-type battery is inserted into the channel.

5. The battery charger of claim 1 , wherein the cap further comprises an interior wall defining the interior channel, and the stopping member is a flange protruding from the interior wall.

6. The battery charger of claim 1 , wherein the cap further comprises an interior wall defining the interior channel, and the stopping member is a plurality of protrusions protruding from the interior wall.

7. The battery charger of claim 1 , wherein the stopping member is shaped to complement a first beveled edge formed with a V-bevel.

8. The battery charger of claim 1 , wherein the stopping member is shaped to complement a second beveled edge formed with a compound V-bevel.

9. The battery charger of claim 1 , wherein the stopping member is shaped to complement a third beveled edge formed with a J-bevel.

10. The battery charger of claim 1 , wherein the stopping member is shaped to complement a fourth beveled edge formed with a compound J-bevel.

11. The battery charger of claim 1 , wherein the stopping member is shaped to complement a fifth beveled edge formed with a convex bevel.

12. The battery charger of claim 1 , wherein the stopping member is shaped to complement a sixth beveled edge formed with a compound convex bevel.

13. An electrical-power supplying product comprising:

one or more batteries of a preselected type, an individual preselected-type battery comprising a lateral surface and a front-end surface, an edge formed between the lateral and front-end surfaces being a beveled edge; and

the battery charger of claim 1 for recharging the one or more preselected-type batteries.

14. The electrical-power supplying product of claim 13 , wherein:

the beveled edge of the individual preselected-type battery is a first beveled edge formed with a V-bevel.

15. The electrical-power supplying product of claim 13 , wherein:

the beveled edge of the individual preselected-type battery is a second beveled edge formed with a compound V-bevel.

16. The electrical-power supplying product of claim 13 , wherein:

the beveled edge of the individual preselected-type battery is a third beveled edge formed with a J-bevel.

17. The electrical-power supplying product of claim 13 , wherein:

the beveled edge of the individual preselected-type battery is a fourth beveled edge formed with a compound J-bevel.

18. The electrical-power supplying product of claim 13 , wherein:

the beveled edge of the individual preselected-type battery is a fifth beveled edge formed with a convex bevel.

19. The electrical-power supplying product of claim 13 , wherein:

the beveled edge of the individual preselected-type battery is a sixth beveled edge formed with a compound convex bevel.

20. The electrical-power supplying product of claim 13 , wherein:

the cap of the individual slot further comprises an interior wall defining the interior channel; and

a portion of the interior wall is shaped to complement the front-end surface of the individual preselected-type battery such that when a respective preselected-type battery is inserted into the channel of the cap of the individual slot, the respective preselected-type battery is mated to the cap of the individual slot.

21. The electrical-power supplying product of claim 13 , wherein:

the stopping member of the cap of the individual slot is shaped to complement and fully cover the beveled edge; and

the beveled edge of the individual preselected-type battery has a height selected to be greater than a height of a positive electrode of the individual preselected-type battery for additionally allowing foolproof use of the battery charger by an end user.

22. The electrical-power supplying product of claim 13 , wherein the individual preselected-type battery further comprises:

a rechargeable raw cell having a cylindrical shape; and

a circuit board including an electronic circuit electrically connected to the raw cell for providing electrical protection to the battery.

23. The electrical-power supplying product of claim 22 , wherein the electronic circuit is configured to provide a voltage step-down function during discharge of the raw cell.

24. The electrical-power supplying product of claim 23 , wherein the electronic circuit is further configured to provide over-charge or over-discharge protection to the raw cell.

25. The electrical-power supplying product of claim 22 , wherein the electronic circuit includes a light-emitting diode (LED) for signaling that the raw cell is under recharging.

26. The electrical-power supplying product of claim 22 , wherein the individual preselected-type battery further comprises a plastic cover for providing protection to the electronic circuit, the plastic cover being formed with the beveled edge.

27. The electrical-power supplying product of claim 22 , wherein the individual preselected-type battery further comprises:

a metal electrode cap electrically connected to the circuit board for forming a positive electrode of the individual preselected-type battery; and

a metal support ring between the raw cell and the circuit board for securely fixing the circuit board and the metal electrode cap at desired locations inside the individual preselected-type battery.

28. The electrical-power supplying product of claim 27 , wherein:

the circuit board is integrated with a wire and a metal pad for connecting the electronic circuit to a positive terminal of the raw cell; and

the electronic circuit is electrically connected to a negative terminal of the raw cell through the metal support ring.

29. The electrical-power supplying product of claim 27 , wherein:

the electronic circuit includes a light-emitting diode (LED) for signaling that the raw cell is under recharging; and

the metal support ring is formed with one or more openings for allowing LED light generated from the electronic circuit to leave the individual preselected-type battery.

30. The electrical-power supplying product of claim 29 , wherein the individual preselected-type battery further comprises a plastic cover for providing protection to the electronic circuit, the plastic cover being transparent or semi-transparent for allowing LED light to leave the individual preselected-type battery.

31. The electrical-power supplying product of claim 27 , wherein the individual preselected-type battery further comprises an insulation tap ring partially covering the metal electrode cap for avoiding splashing water from going inside the individual preselected-type battery.

32. The electrical-power supplying product of claim 27 , wherein:

the individual preselected-type battery further comprises a plastic cover for providing protection to the electronic circuit, the plastic cover being formed with the beveled edge;

the metal support ring includes one or more slot features for locking with the plastic cover; and

the plastic cover includes one or more locking features for locking with the metal support ring.

33. The electrical-power supplying product of claim 22 , wherein the individual preselected-type battery further comprises a plastic label formed by a shrinkable sleeve for laterally covering the individual preselected-type battery.