Battery charger

Abstract

A device (100) such as a battery charger includes a body (102), a movable member (104, 402), and a plurality of battery bays (108). Moving the member (104, 402) toward a first position increases a distance between respective first (132) and second (114) battery contacts so that a battery may be inserted with zero or substantially zero insertion force. Moving the member (104, 402) in the second direction decreases the distance between the first and second battery contacts. In one implementation, the device (100) is polarity agnostic.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:

FIGS. 1A and 1B are perspective views of a battery charger.

FIG. 1C the sectional view indicated by line 1C-1C of FIG. 1B.

FIG. 1D is the sectional view indicated by line 1D-1D of FIG. 1B.

FIG. 1E is the sectional view indicated by line 1E-1E of FIG. 1B, showing the battery charger with a cover open.

FIG. 1F is the sectional view indicated by line 1E-1E of FIG. 1B, showing the battery charger with the cover closed.

FIG. 2 is a bottom view of a battery charger.

FIGS. 3A through 3D depict bays of a battery charger.

FIG. 4 is a top view of a battery charger.

FIG. 5 is a top view of a battery charger.

FIG. 6 depicts a recessed battery contact.

FIG. 7 is a block diagram of a polarity agnostic charging circuit.

FIG. 8 depicts battery contact electrical connections.

FIG. 9 is a cross-sectional view of a battery tray.

DETAILED DESCRIPTION

With reference to FIGS. 1A and 1B, a battery charger 100 includes a body 102 and a cover 104 which is mounted for pivotal motion relative to the body 102 about a pivot or hinge axis 103. FIG. 1A depicts the cover 104 in a closed position, whereas FIG. 1B depicts the cover in an open position which allows a user to access a battery receiving region 106. In the illustrated embodiment, the battery receiving region 106 includes five (5) battery receiving bays 108₁, 108₂, 108₃, 108₄, 108₅.

The first through fourth bays 108_1-4 are configured to receive one or more generally cylindrical batteries having positive and negative terminals disposed on opposite ends of the battery. The batteries are received in the bays 108_1-4 with their longitudinal axes extending generally in the direction 110. The bays 108_1-4 each include movable contact supports 112_1-4 which are disposed generally toward the rear of the respective bays 108_1-4. The supports 112 carry first battery contacts 132a,b,c (see FIG. 1C) which are adapted to make electrical contact with the first terminals of the battery or batteries received in the respective bays 108_1-4. Second, generally stationary battery contacts 114_1-4, which are disposed generally toward the front of the respective bays 108_1-4, are adapted to make electrical contact with the first terminal of the battery or batteries received in the bays 108_1-4.

As will be described further below, the first 132 and second 114 battery contacts are zero insertion and removal force battery contacts. More specifically to the illustrated embodiment, the contact supports 112 are in operative mechanical communication with the cover 104 so that, when the cover is in the open position, the spacing between the contacts 132, 114 is greater than the longitudinal dimension of the battery or batteries to be inserted in the respective bays 108_1-4. As a consequence, the batteries can be inserted in the bays 108_1-4 without overcoming the contact force. When the cover 104 is in the closed position, the spacing between the contacts 132, 114 is such that the contacts 132, 114 make electrical contact with the terminals of the battery or batteries received in the respective bays. Reopening the cover 104 again increases the spacing between the contacts 112, 114 so that the batteries can be removed without overcoming the contact force.

The fifth bay 108₅ is configured to receive first 116₁ and second 116₂ generally rectangular nine volt (9V) batteries for charging. Suitable battery contacts disposed near the bottom of the fifth bay 108₅ provide the requisite battery connections. Also disposed in the housing 102 is conventional battery charging circuitry. A power cord 118 connects the charger 100 to a suitable power source, for example a wall cube which can be plugged into a standard alternating current (AC) power receptacle. An internally mounted, cover-actuated pushbutton switch automatically activates the charging circuitry when the cover 104 is closed, and a cover-mounted user interface 120 such as a liquid crystal display (LCD) indicates the operational status of the charger 100.

An exemplary one of the bays 108_1-4 will now be described with additional reference to FIGS. 1C and 1D, it being understood that the first through fourth bays 108_1-4 are similarly configured. Note that the batteries depicted in FIG. 1B have been omitted for ease of explanation.

The bay 108 includes a first, rear end wall 122 and a second, spaced apart front end wall 124. The distance between the walls 122, 124 is greater than the longitudinal dimension of the largest battery to be received in the bay 108.

Disposed at the bottom of the bay 108 is a battery tray which includes first 126_a and second 126_b outer battery supports and a third, central battery support 126_c. The radii of the outer battery supports 126_a, 126_b are selected to support batteries having a relatively smaller radial dimension, for example standard AA and AAA size batteries. The radius of the central battery support 126_c is slightly larger so as to additionally support batteries of a relatively larger radial dimension, for example standard C and D size batteries.

The second battery contact 114, which is located at the second, front end wall 124, includes first 114_a and second 114_b outer battery contacts and a third, central battery contact 114_c. The outer contacts 114_a, 114_b are positioned relative to the outer battery supports 126_a, 126_b so as to make contact with the second terminal of AAA and AA size batteries received in the bay 108. The central contact 114_c is likewise positioned relative to the central battery support 126, so as to make contact with the second terminal of AAA, AA, C, and D size batteries.

The contact support 112 is fabricated from a metallic or other conductive material. First 132_a, second 132_b, and third 132_c contacts are formed as protrusions which make electrical contact with the first terminal of the battery or batteries received in the bay 108. The contact support 112 is mounted for slidable motion in a slot 138 formed in the battery tray. As will be appreciated, the direction of motion is generally parallel to the longitudinal axes 110 of the battery or batteries. A spring 140 connected between the contact support 112 and the underside of the battery tray nearer to the front end wall 114 urges the contact support 112 toward the front end wall 114.

FIG. 2 is a bottom view of the charger 100 with the bottom cover removed for ease of explanation. The cover 104 is pivotally attached to the housing 102 via hinge pins 142 which are advantageously formed as an integral part of the cover 104 and which snappingly engage corresponding recesses 144 in the body 102. First 146₁ and second 146₂ slide members are disposed on the underside of the battery trays for slidable motion in the direction 110. The rear portion 152 of the slide members 146 releasably engages front facing shoulders 154 formed on the contact supports 112. More specifically to the illustrated embodiment, the first slide member 146₁ releasably engages the first 112₁ and second 112₂ contact supports, whereas the second slide member 146₂ releasably engages the third 112₃ and fourth 112₄ contact supports. First 148₁ and second 148₂ link members are connected between the cover 104 and the respective first 146₁ and second 146₂ slide members.

With reference to FIGS. 1E and 1F, a first end of each link members 148 is pivotally connected to the to the cover 104 for rotational motion about a pivot or hinge axis 150, while the second end of each link member 148 is pivotally connected to a respective slide member 146 for rotational motion about a pivot or hinge axis 152.

Opening the cover 104 urges the link members 148₁, 148₂ and hence their respective slide members 146₁, 146₂ toward the rear of the battery receiving region 106. The rear 154 of the slide members 146 releasably engages the shoulders 156 of the respective contact supports 112, overcoming the force exerted by the springs 140 and thus moving the contact supports 112 toward the rear of the battery receiving region 106. Note that, when the cover 104 is in the open position, a line extending between the link arm 148 pivot axes 150, 152 is located below the cover pivot axis 130. As a consequence, the force exerted by the springs 140 generates a moment about the pivot axis 130 which tends to maintain the cover 104 in the open position.

Closing the cover 104 causes the link members 148 and the slide members 146 to move toward the front of the battery receiving region 106. As a consequence, the springs 140 urge the contact supports 112 forward in coordination with the closing of the cover 104. If a battery is not installed in a given bay 108_1-4, the contact support 112 moves forward to the limit of its travel. Where a battery (or batteries) is received in a bay 108_1-4, a contact 132 engages the first end the battery, thus urging it toward the second battery contact 114. When the second end of the battery contacts the second battery contact 114, the contact support 112 is unable to move forward and the spring 140 applies a suitable contact force. The rear 154 of the respective slide member 146 disengages from the shoulder 156 of the respective contact support 112 so that the link member 148 and the slide member 154 continue to move forward in coordination with the closing of the cover 104.

Pivoting the cover 104 thus retracts each of the movable battery contacts 114, thus allowing the user to insert batteries in and/or remove batteries from the desired bays 108_1-4 with zero insertion or removal force. As will also be appreciated, the forward travel of the respective contact supports 112_1-4 depends on the size of the battery or batteries received in its corresponding bay 108_1-4. As a result, the user may insert different size batteries in each bay 108_1-4. Thus, for example, a user may elect to insert a single C size battery in one of the bays, one or more AAA size batteries in another of the bays, a single D size battery in still another bay, one or more AA size batteries in the fourth bay. Of course, the foregoing is but one possibility, and other combinations are possible.

Still other variations are contemplated. For example, one or more of the bays 108_1-4 may be configured to selectively receive a single D size battery, a single C size battery, up to four (4) AA size batteries, or up to four (4) AAA size batteries. The battery supports and contact configuration of a device having two (2) such bays 108₁, 108₂ is illustrated in FIGS. 3A-3D.

An exemplary bay 108 will now be described, it being understood that the first 108₁ and second bays 108₂ are similarly configured. The bay 108 includes a battery support 302 having a generally funnel or V-shaped section. With reference to FIG. 3A, the battery support 302 supports a D-size battery 304 so that its longitudinal axis is positioned at the horizontal center of the bay 108. A battery contact 114_D is positioned relative to the battery support 302 so as to make electrical contact with the second terminal of the battery 304.

With reference to FIG. 3B, the battery support 302 also supports a C-size battery 306 so that its longitudinal axis is positioned at the horizontal center of the bay 108 and slightly below that of the D-size battery 304. A battery contact 114_C is positioned relative to the battery support 302 so as to make electrical contact with the second terminal of the battery 304.

Turning now to FIG. 3C, the battery support 302 also supports up to four (4) AA size batteries 308 in a two (2) dimensional close packed array in which adjacent rows and columns are offset by one-half (½) the battery radial dimension R. A plurality of battery contacts 114_AA are positioned relative to the battery support 302 so as to make electrical contact with the second terminals of the batteries 308. As can be seen, a centroid of the array is coincident with a horizontal center of the battery support.

With reference now to FIG. 3D, the battery support 302 similarly supports up to four (4) AAA size batteries 310, again in a two (2) dimensional close packed array with adjacent rows and columns offset by the radius r of the batteries 310. A plurality of battery contacts 114_AAA are positioned relative to the battery support 302 so as to make electrical contact with the second terminals of the batteries 310.

The contacts 132 are likewise configured to make electrical contact with the first terminals of the respective batteries 304, 306, 308, 310. Note that the various contacts 114 need not be physically or electrically discrete; some or all of them may be combined so as to provide the desired electrical connections. In one example, the D size battery contact 114_D, the C size battery contact 114_C, one of the AA size battery contacts 114_AA, and one of the AAA size battery contacts 114_AAA are combined in a single contact, and the remaining AA size battery contacts 114_AA and AAA size battery contacts 114_AAA are likewise combined in pair-wise fashion. Note also that one or more of the contacts 132 may also be electrically discrete.

A particular advantage the arrangement described above is that the battery support 302 tends to function as a hopper, thus using the force of gravity to funnel the battery or batteries inserted into a bay 108 into their correct position(s). As a consequence, the batteries are largely self positioning, particularly when the battery support 302 is used in combination with zero insertion force battery contacts 112, 114 and the hopper opening is disposed generally physically upwardly in the absolute sense. While the illustrated hopper accommodates one (1) C or D size batteries or up to four (4) AAA or AA size batteries smaller or larger hoppers which accommodate fewer or larger batteries or combinations of battery sizes may also be implemented.

Still other variations are contemplated. For example, one or more of the bays 108 may be configured to receive only a single battery. Thus, a bay 108 may be configured to receive a single D size battery, a single C size battery, a single AA size battery, or a single AAA size battery. In yet another alternative, one or more of the bays 108 may also be configured to receive multiple batteries of only a single size or of a relatively limited range of sizes. For example, a bay 108 may be configured receive a plurality of AA or AAA batteries, or otherwise receive any two (2) or more battery sizes selected from the group of AAA, AA, C, and D-size batteries. Still other battery sizes are also contemplated.

Greater or lesser numbers of bays 108 may also be provided. One or more of the bays 108 may also be provided with its own cover 104. A given cover 104 may also actuate the contacts 132 or more than one but less than all of the bays 108. A particular advantage of such arrangements is that they facilitate the independent operation of the various bays 108, for example where the user wishes to insert batteries in or remove batteries from a first bay while the batteries in another bay continue to charge.

The contacts 132, 114 may also be configured so that, when the cover 104 is in the open position, the spacing between the contacts 132, 114 is approximately equal to the longitudinal dimension of a battery to be received in the bay 108. As will be appreciated, such an arrangement simplifies insertion and removal of the batteries, especially compared to arrangements in which the contact supports 112 must be grasped and moved by the user. The contacts 132, 114 may also be configured to provide substantially zero insertion and removal force contacts. More particularly, the contact spacing is established so that while the contact force applied during insertion and/or removal of a battery is non-zero, it is nonetheless less than the contact force applied during charging.

In another alternative implementation, one or more of the bays 108 is provided with a lever which operates similarly to the cover 104. The lever may also be configured as a thumbwheel. In still another implementation, the movable battery contacts 112 may be actuated by a user operated slider accessible from the top of the charger 100, with a detent holding the slider in the open or retracted position.

Various link member 148 and slide member 146 implementations are also contemplated. For example, three (3) or more bays may share a common link member 148; a link member 148 may be provided in connection with each bay 108. The slide member or members 146 may be also be omitted, with a protrusion, pin, or the like extending from the link member 148 and engaging the moving battery contact 114.

The foregoing discussion has focused on an arrangement in which the battery trays are substantially stationary with respect to the body 102. Turning now to FIG. 4, a charger 100 includes a generally sliding or telescoping tray 402 located at the front of the charger 100 and which is movable relative to the body 102 in the direction 110. The movable battery contacts 112 are likewise movable in the direction 110 in the slots 138, with springs 140 urging the movable contacts 140 toward the front of the body 102. Suitable material free regions or slots 404 provided in the tray 402 provide clearance for the movable contacts 112 and/or the springs 140. In one implementation, the tray 402 is actuated manually by the user, with a suitable latch maintaining the tray 402 in the closed position. In another implementation, the tray is motorized.

With the tray 402 in the open position (as shown in FIG. 4), the springs 140 urge the movable battery contacts 112 toward the front of the charger 100. Where a battery (or batteries) is received in a bay 108, closing the tray 402 causes the first end of the battery to engage the corresponding contact support 112. If the second end of the battery is not already in contact with the front end wall 124 (or the contacts 114, as the case may be), the movable contact 114 tends to urge the battery forward. Upon reaching the front of the bay 108, the second end of the battery then causes the contact support 112 to retract in coordination with the closing of the tray 402.

In another variation which is illustrated in FIG. 5, the contact supports 112 may be carried by the tray 402, with springs 140 urging the movable contact supports 112 toward the front of the tray 402. When the tray 402 is opened, one or more protrusion(s) or pin(s) 408 extending from the bottom or sides of the housing 102 engage forward facing shoulders disposed on the movable contacts 112, thereby retracting them. When the cover is closed, the springs 140 urge the movable contacts 112 forward in the tray 402.

According to yet another implementation, the first 112 and second 114 contacts are formed at the first 122 and second 124 ends of the tray 402. A spring 140 urges the tray 402 toward the closed position, while a detent holds the tray 402 in the open position.

Various electrical arrangements are also contemplated. For example, a separate charging channel may be provided each of the bays 108. In one such implementation, the battery contacts of a given bay is connected to the battery charging circuitry 802 as shown in FIG. 8. A particular advantage of such an arrangement is that the charging energy supplied to the outer batteries may be applied independently. However, it will also be appreciated that the second contacts 114a,b,c may also be connected together so that the outer batteries are connected electrically in parallel during charging. Similar connection schemes may also be implemented in connection with the arrangement of FIG. 3D, taking into account the relatively larger number of batteries.

As illustrated schematically in FIG. 6, the first or second battery contacts 602 may be recessed in their respective support 604. Where a battery is inserted with the incorrect polarity, the negative battery terminal does not make electrical contact with the recessed contact 602. As a consequence, charging energy is not applied with the incorrect polarity.

In still another arrangement, the battery contacts 132, 114 and the charger electrical circuitry are designed to be polarity agnostic. For the purposes of the present application, polarity agnostic is defined to mean that the battery contacts 132, 114 will make electrical contact with either of the positive and negative terminals of a battery and that the electrical device will operate properly (e.g., a battery charger will charge batteries or a battery powered device will perform the function of the device) irrespective of the polarity in which the battery is inserted in a bay 108.

A block diagram of an exemplary polarity agnostic battery charging circuit is depicted in FIG. 7. As shown at FIG. 7, the charging circuit includes a polarity detection circuit 702 and battery charging circuitry 704. The polarity detection circuitry 702 determines the polarity of one or more of the batteries received in a bay 108. The battery charging circuitry 704 applies the desired charging energy to the battery or batteries, with the polarity of the charging energy selected based on the detected battery polarity. Various polarity detection techniques are known in the art and can be selected based on application specific requirements. In such a configuration, the respective first 132 and second 114 battery contacts for the various batteries in a given bay 108 are not electrically connected so that the polarity of each battery may be individually detected and accounted for.

FIG. 9 is a cross sectional view of an alternate implementation of a battery tray 126 for an exemplary bay 108. The tray 126 is depicted generally at the position of section ID-ID shown in FIG. 1. The tray includes first 902a and 902c second outer battery supports which are dimensioned to support AAA size batteries. Additional outer supports 904a, 904b are likewise dimensioned to support a pair of relatively larger AA size batteries. A central region 906 includes a pair of upstanding, spaced apart protrusions 908, 910 which are configured to support AAA, AA, C, or D size cells. As illustrated, the spacing between and height of the protrusions are selected so that the batteries do not contact and are thus unsupported by the surface 912. Thus, the batteries are supported substantially along two (2) lines defined by the protrusions 908, 910. Alternately, the protrusions 908, 910 may be dimensioned so that a given size battery (e.g., a AAA size battery is also supported by the surface 912. It should also be noted that, as illustrated, the bay 108 will concurrently accept up to three (3) AAA or AA size batteries, with one (1) battery disposed in each of the outer positions and a third battery disposed in the central position.

It should also noted that the above described techniques are not limited to use with battery chargers and may also be used in connection with battery powered electrical devices.

The invention has been described with reference to the preferred embodiments. Of course, modifications and alterations will occur to others upon reading and understanding the preceding description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims.

Claims

1. A polarity agnostic battery charger having zero insertion force battery contacts.

2. A battery charger comprising: a first battery contact;a second battery contact;a first user operable member in operative mechanical communication with and movable with respect to the first battery contact, wherein moving the first member in a first direction causes the first battery contact to move away from the second battery contact so that the distance between the first and second battery contacts is approximately equal to or greater than a longitudinal dimension of a first generally cylindrical battery, and wherein moving the first member in a different, second direction causes the first battery contact to move toward the second battery contact so that the first and second battery contacts make electrical contact with respective first and second terminals of the first battery when the first battery is disposed between the first and second battery contacts.

3. The battery charger of claim 2 wherein the first member includes a cover which is movable to an open position and the first direction is toward the open position.

4. The battery charger of claim 2 wherein the first member includes a battery tray.

5. The battery charger of claim 2 wherein moving the first member in a first direction includes pivoting the first member about a pivot axis.

6. The battery charger of claim 2 including a second member in operative mechanical communication with the first battery contact and the first member, wherein the second member releasably urges the first battery contact away from the second battery contact.

7. The battery charger of claim 6 including a spring in operative mechanical communication with the first battery contact, wherein the spring urges the first battery contact toward the second battery contact.

8. The battery charger of claim 6 wherein the moving the first member in the second direction causes the second member to disengage from the first battery contact to accommodate batteries having different battery sizes.

9. The battery charger of claim 2 including a third battery contact;a fourth battery contact;

10. The battery charger of claim 2 including at least a first upwardly facing battery support.

11. The battery charger of claim 2 including a battery polarity detection circuit which detects the polarity in which the first battery is inserted in the first battery receiving region.

12. A method comprising: in response to a user initiated movement of a first member toward a first position, releasably engaging a second member in operative mechanical communication with a first battery contact so as to increase a distance between the first battery contact and a second battery contact;while the first member is in the first position, receiving a first generally cylindrical battery between the first and second battery contacts, wherein the battery has a longitudinal dimension which is less than or approximately equal to the distance between the first and second battery contacts;in coordination with a movement of the first member toward a second position, decreasing the distance between the first and second battery contacts so that the first and second battery contacts make electrical contact with respective first and second terminals of the first battery.

13. The method of claim 12 further including, following the step of decreasing the distance, disengaging from the second member in response to a further movement of the first member toward the second position.

14. The method of claim 12 further including, in response to a user initiated movement of the first member toward the first position, releasably re-engaging the second member until the distance between the first and second battery contacts is approximately equal to or greater than the longitudinal dimension of the first battery.

15. The method of claim 12 wherein the second member is in operative mechanical communication with at least two battery contacts and the step of receiving includes receiving at least two batteries.

16. The method of claim 15 wherein the second member is in operative communication with at least four battery contacts and the step of receiving includes receiving four batteries.

17. The method of claim 16 wherein the batteries are disposed in a two-dimensional array and wherein adjacent rows of the array are offset by a radius of the batteries.

18. The method of claim 12 further including in response to the user initiated movement of the first member toward the first position, releasably engaging a third member in operative mechanical communication with a third battery contact so as to increase a distance between the third battery contact and a fourth battery contact;while the first member is in the first position, receiving a second generally cylindrical battery between the third and fourth battery contacts, wherein the second battery has a longitudinal dimension which is less than or approximately equal to the distance between the third and fourth battery contacts;in coordination with the movement of the first member toward the second position, decreasing the distance between the third battery contact and the fourth battery contact so that the third and fourth battery contacts make electrical contact with respective first and second terminals of the second battery.

19. The method of claim 18 wherein the first battery is a AAA size battery and the second battery is a AA, C, or D size battery.

20. The method of claim 12 wherein the first member includes a cover and the first position is an open position which allows a user to insert a battery between the first and second battery contacts.

21. The method of claim 12 wherein the user initiated motion includes a translational motion.

22. The method of claim 12 wherein the user initiated motion is a motorized motion.

23. The method of claim 12 including using a polarity detection circuit operatively connected to the first and second battery contacts to determine the polarity of the first battery.

24. The method of claim 12 including charging the first battery or using the first battery to power an electrical device.

25. The method of claim 12 wherein the longitudinal dimension of the first battery is less than the distance between the first and second battery contacts.

26. The method of claim 12 including using a spring to maintain the first member in the first position;using the spring to decrease the distance between the first and second battery contacts

27. An apparatus including: a body;a first cover mounted for pivotal motion relative to the body, wherein the cover pivots between an open position for inserting at least a first battery in a battery receiving region of the apparatus and a second position;a first pair of battery contacts in operative mechanical communication with the first cover, wherein pivoting the cover to the open position allows a first battery to be inserted between the first pair of battery contacts with substantially zero insertion force and pivoting the cover to the second position causes the first pair of battery contacts to apply a contact force to terminals of the first battery.

28. The apparatus of claim 27 including a first link member in operative mechanical communication with the first cover for releasably urging one of the first pair of contacts away from the other of the first pair of contacts.

29. The apparatus of claim 28 including a spring for urging one of the first pair of contacts toward the other of the first pair of contacts.

30. The apparatus of claim 27 including a second pair of battery contacts in operative mechanical communication with the first link member, wherein pivoting the cover to the open position allows a second battery to be inserted between the first pair of battery contacts with substantially zero insertion force and pivoting the cover to the second position causes the first pair of battery contacts to make electrical contact with first and second terminals of the second battery.

31. The apparatus of claim 30 including a slide member in operative mechanical communication with the first link member for releasably urging one of the first pair of contacts away from the other of the first pair of contacts and one of the second pair of contacts away from the other pair of contacts to accommodate different size batteries.

32. The apparatus of claim 27 including a battery bay configured to receive exactly one, two, or three AAA size batteries, exactly one, two, or three AA size batteries, exactly one C size battery, or exactly one D size battery.

33. An apparatus including: a battery support having a generally funnel shaped cross section and which supports four generally cylindrical batteries in a two dimensional close packed array;a plurality of zero insertion force battery contacts for making electrical contact with first and second terminals of the batteries.

34. The apparatus of claim 33 wherein the plurality of contacts include contacts for making electrical contact with first and second terminals of AAA and AA size batteries.