Patent Description:
Multi-bay battery chargers can charge battery packs in series (i.e., one at a time) or in parallel (i.e., simultaneously). When a multi-bay charger charges battery packs in series, the battery pack currently being charged typically finishes charging before the next battery begins charging. In addition, multi-bay battery chargers are usually large and cumbersome to carry.

<NPL>, relates to an operation manual for a BC-L160 battery charger. The battery charger comprising charge indicators, a display, a display button, a mode selector, a power indicator, a DC OUT connector, four battery pack attachments and release buttons. According to its title and abstract <CIT> relates to a battery charger for simultaneously charging a plurality of rechargeable batteries, for example of AA or AAA size, comprises a base having a plurality of recesses each for receiving a respective battery. The recesses are positioned such that each battery is oriented horizontally with vertical cooling slots substantially along the length of the battery.

Aspects of the present invention relate to a battery charger as set out in the appended independent claims. Optional features of the invention are set out in the dependent claims.

In one illustrative example there is provided a battery charger including a housing and a plurality of charging ports coupled to the housing. Each charging port is configured to connect a battery pack to the battery charger. The battery charger also includes a charging circuit positioned within the housing and electrically coupled to the plurality of charging ports. The charging circuit is operable to charge the battery packs connected to the plurality of charging ports in series. The battery charger further includes a skip switch coupled to the charging circuit. The skip switch is operable to skip a battery pack currently being charged and advance to another battery pack connected to the battery charger.

In another illustrative example there is provided a method of charging battery packs in series. The method includes connecting a first battery pack and a second battery pack to a battery charger, charging the first battery pack, actuating a skip switch on the battery charger while the first battery pack is charging, and stopping charging of the first battery pack and initiating charging of the second battery pack in response to actuating the skip switch.

In yet another embodiment, there is provided a battery charger including a housing having a handle to facilitate lifting and carrying the battery charger and a plurality of charging ports coupled to the housing. Each charging port is configured to connect a battery pack to the battery charger. The battery charger also includes a charging circuit positioned within the housing and electrically coupled to the plurality of charging ports. The charging circuit is operable to charge the battery packs connected to the plurality of charging ports. The plurality of charging ports is spaced apart on the housing such that, when a battery pack is connected to each charging port, the battery charger is balanced around the handle.

In still another embodiment, there is provided a battery charger including a housing and a plurality of charging ports coupled to the housing. Each charging port is configured to connect a battery pack to the battery charger. The battery charger also includes a charging circuit having a first circuit board and a second circuit board. The first and second circuit boards are mounted in parallel within the housing. The charging circuit is electrically coupled to the plurality of charging ports to charge the battery packs connected to the plurality of charging ports.

In yet still another embodiment, there is provided a battery charger including a housing having four side surfaces arranged in a generally rectangular pattern, an upper surface extending between and arranged generally perpendicular to the four side surfaces, and a handle extending from the upper surface to facilitate lifting and carrying the battery charger. The battery charger also includes a plurality of charging ports coupled to the housing. Each charging port is configured to connect a battery pack to the battery charger. The plurality of charging ports is spaced apart on the housing such that, when a battery pack is connected to each charging port, the battery charger is balanced around the handle. The battery charger further includes a charging circuit having a first circuit board and a second circuit board. The first and second circuit boards are mounted in parallel within the housing. The charging circuit is electrically coupled to the plurality of charging ports to charge the battery packs connected to the plurality of charging ports in series. The battery charger also includes a skip switch coupled to the charging circuit. The skip switch is operable to skip a battery pack currently being charged and advance to another battery pack connected to the battery charger.

<FIG> illustrate a multi-bay battery charger <NUM> that is configured to support and charge multiple battery packs 14A-F. In the illustrated embodiment, the battery charger <NUM> supports and charges up to six battery packs 14A-F. In other embodiments, the battery charger <NUM> is configured to support and charger fewer or more battery packs 14A-F. The battery packs 14A-F are, for example, <NUM>-volt Li-ion power tool battery packs. In other embodiments, the battery packs 14A-F may have different voltages (e.g., <NUM>-volt, <NUM>-volt, <NUM>- volt, <NUM>-volt, <NUM>-volt, etc.) and/or different chemistries (e.g., NiMH, NiCd, etc.). The illustrated charger <NUM> includes a base <NUM>, a housing <NUM>, six charging ports 26A-F (<FIG>), and a charging circuit <NUM> (<FIG>).

The base <NUM> is coupled to a bottom portion of the housing <NUM>. The base <NUM> is generally larger (e.g., wider and longer) than the housing <NUM> to add stability to the charger <NUM>. As shown in <FIG>, feet <NUM> extend from a bottom surface <NUM> of the base <NUM>. The feet <NUM> space the bottom surface <NUM> of the base <NUM> and the housing <NUM> apart from a surface (e.g., a table, a counter, the floor, etc.) that supports the charger <NUM> to facilitate cooling interior components (e.g., the charging circuit <NUM>) of the charger <NUM>. The base <NUM> also includes two receptacles <NUM> on the bottom surface <NUM>. The receptacles <NUM> are configured to receive screws, or other fasteners, to mount the charger <NUM> to a wall or other vertical surface. The receptacles <NUM> also extend from the bottom surface <NUM> of the base <NUM> to function as additional feet.

The housing <NUM> extends outwardly from the base <NUM> and includes four side surfaces <NUM>, <NUM>, <NUM>, <NUM> and an upper surface <NUM>. The side surfaces <NUM>, <NUM>, <NUM>, <NUM> are arranged perpendicular to one another in a generally rectangular pattern. The upper surface <NUM> is spaced apart from the base <NUM> and extends generally perpendicular to the side surfaces <NUM>, <NUM>, <NUM>, <NUM>. As shown in <FIG>, the housing <NUM> is composed of two clamshell halves <NUM>, <NUM> that connect together to define the surfaces <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of the housing <NUM>. The clamshell halves <NUM>, <NUM> thereby enclose the interior components of the charger <NUM>. In the illustrated embodiment, the clamshell halves <NUM>, <NUM> are aligned and secured together by bosses <NUM>, <NUM> and screws (not shown). In other embodiments, the housing <NUM> may be formed as a single piece that is connected to the base <NUM>.

Referring to <FIG> and <FIG>, the illustrated charger <NUM> has a length L, a width W, and height H defined by the base <NUM> and the housing <NUM>. The length L is measured between edges of the base <NUM> adjacent the side surfaces <NUM>, <NUM>. The width W is measured between edges of the base <NUM> adjacent the side surfaces <NUM>, <NUM>. The height H is measured between the bottom surface <NUM> of the base <NUM> and the upper surface <NUM> of the housing <NUM>. A ratio of the length L, to the width W, to the height H of the battery charger <NUM> is about <NUM>:<NUM>:<NUM>. In the illustrated embodiment, the length L is about <NUM> (<NUM> inches), the width W is about <NUM> (<NUM> inches), and the height H is about <NUM> (<NUM> inches). As such, the charger <NUM> is relatively compact and has a total volume of less than <NUM> cubic cm (<NUM> cubic inches). Furthermore, a footprint area of the charger <NUM>, which is the amount of surface area taken up by the charger <NUM> when the charger <NUM> is positioned on a table or wall (measured by the length L times the width W), is less than <NUM> square cm (<NUM> square inches).

Referring back to <FIG>, the side surfaces <NUM>, <NUM>, <NUM>, <NUM> are generally vertically oriented when the charger <NUM> is supported by the base <NUM> on a table. Each side surface <NUM>, <NUM>, <NUM>, <NUM> supports at least one of the charging ports 26A-F. In the illustrated embodiment, two of the side surfaces (e.g., the front and rear side surfaces <NUM>, <NUM>) each support two charging ports 26A-B, 26D-E, while the other side surfaces <NUM>, <NUM> each support one charging port 26C, 26F. In other embodiments, the charger <NUM> may include a total of four charging ports and each of the side surfaces <NUM>, <NUM>, <NUM>, <NUM> may only support one charging port. In still other embodiments, the charger <NUM> may include eight or more charging ports and each of the side surfaces <NUM>, <NUM>, <NUM>, <NUM> may support two or more charging ports.

In the illustrated embodiment, the housing <NUM> also includes a handle <NUM> extending from the upper surface <NUM>. As shown in <FIG> and <FIG>, the handle <NUM> is centrally positioned on the charger <NUM> such that a central axis <NUM> defined by the side surfaces <NUM>, <NUM>, <NUM>, <NUM> of the housing <NUM> extends through the handle <NUM>. The illustrated handle <NUM> defines a longitudinal axis <NUM> that is generally parallel to the side surfaces <NUM>, <NUM> and is generally perpendicular to the side surfaces <NUM>, <NUM>. The handle <NUM> thereby defines an elongated grip that is generally parallel to and spaced apart from the upper surface <NUM> to facilitate lifting and carrying the charger <NUM>.

The charging ports 26A-F are spaced apart around the handle <NUM> to help balance the charger <NUM> around the handle <NUM>. That is, the handle <NUM> is positioned on the charger <NUM> so that the weight of the battery packs 14A-F, when connected to the charging ports 26A-F, is balanced around the handle <NUM>. Referring to <FIG>, the charging ports 26A, 26B, 26D, 26E on the side surfaces <NUM>, <NUM> define a first circle Cl that generally extends through a midpoint of each port 26A, 26B, 26D, 26E. Similarly, the charging ports 26C, 26F on the side surfaces <NUM>, <NUM> define a second circle C2 that generally extends through a midpoint of each port 26C, 26F. Both circles Cl, C2 have their origin at the central axis <NUM>. Each of the charging ports 26A-F is diametrically opposed from another charging port 26A-F around its respective circle Cl, C2. For example, the first charging port 26A is diametrically opposed from the fourth charging port 26D around the first circle Cl, the second charging port 26B is diametrically opposed from the fifth charging port 26E around the first circle Cl, and the third charging port 26C is diametrically opposed from the sixth charging port 26F around the second circle C2. As such, each of the battery packs 14A-F, when connected to the charger <NUM>, is located opposite another battery pack 14A-F to balance the weights of the packs 14A-F around the handle <NUM>. Such an arrangement facilitates lifting and carrying the charger <NUM> by the handle <NUM>.

As shown in <FIG>, each of the charging ports 26A-F includes a connecting structure <NUM> and electrical contacts <NUM>. In the illustrated embodiment, the connecting structures <NUM> include guide rails <NUM> configured to receive slide-on style battery packs. The guide rails <NUM> are arranged generally parallel to the central axis <NUM> of the housing <NUM> to support the battery packs 14A-F generally vertically when the charger <NUM> is positioned on a table. The guide rails <NUM> also inhibit the packs 14A-F from sliding off of the charger <NUM> when the charger <NUM> is carried by the handle <NUM>. In particular, the guide rails <NUM> are arranged such that the battery packs 14A-F are slid downward (e.g., toward the base <NUM>) to connect the packs 14A-F to the charging ports 26A-F. In other embodiments, the connecting structures <NUM> may be configured to receive different styles of battery packs, such as tower style battery packs.

As shown in <FIG>, the electrical contacts <NUM> of the charging ports 26A-F are coupled to the charging circuit <NUM>. The charging circuit <NUM> is positioned within the housing <NUM> and charges the battery packs 14A-F when the packs 14A-F are connected to the charging ports 26A-F. The illustrated charging circuit <NUM> includes two circuit boards <NUM>, <NUM> that are mounted in parallel within the housing <NUM>. The circuit boards <NUM>, <NUM> are generally the same shape and size. The charging circuit <NUM> is split onto the two circuit boards <NUM>, <NUM> to reduce the overall size of the battery charger <NUM>. In the illustrated embodiment, the circuit boards <NUM>, <NUM> are arranged generally vertically within the housing <NUM> such that the boards <NUM>, <NUM> extend between the side surfaces <NUM>, <NUM>, but face the side surfaces <NUM>, <NUM> of the housing <NUM>. Furthermore, the circuit boards <NUM>, <NUM> are arranged generally perpendicular to the upper surface <NUM> of the housing <NUM> and the bottom surface <NUM> of the base <NUM>. This arrangement of the circuit boards <NUM>, <NUM> helps reduce the size, and particularly the footprint area, of the charger <NUM>. In other embodiments, the charging circuit <NUM> may be split onto three or more circuit boards and/or the circuit boards <NUM>, <NUM> may be arranged horizontally within the housing <NUM>.

In the illustrated embodiment, the battery charger also includes six sets of indicator lights 106A-F coupled to the charging circuit <NUM>. The illustrated indicator lights 106A-F are light-emitting diodes (LEDs). As shown in <FIG> and <FIG>, the LEDs 106A-F extend from the upper surface <NUM> of the housing <NUM>. Each set of LEDs 106A-F corresponds to one of the charging ports 26A-F to indicate an operational status. For example, a continuous red light indicates the battery pack is charging, a continuous green light indicates charging is complete, and flashing red and green lights indicate an error. In addition, if a battery pack is connected to a charging port while another battery pack is already being charged, one of the LEDs (e.g., a red LED) may flash to indicate that charging is pending and will begin when the other battery pack is finished charging.

The LEDs 106A-B, 106D-E corresponding to the four charging ports 26A-B, 26D-E on the front and rear side surfaces <NUM>, <NUM> of the housing <NUM> are supported on the housing <NUM> beneath the handle <NUM>. That is, the LEDs 106A-B, 106D-E are generally covered by the handle <NUM> when the charger <NUM> is viewed from above (as in <FIG>). The LEDs 106C, 106F corresponding to the two charging ports 26C, 26F on the other side surfaces <NUM>, <NUM> of the housing <NUM> are contoured to match the shape of the transition areas between the handle <NUM> and the upper surface <NUM> so that the LEDs 106C, 106F are generally flush with the housing <NUM>. Such positioning and configurations help protect the LEDs 106A-F from impacts and other forces, reducing the possibility of shearing or otherwise damaging the LEDs 106A-F.

In operation, the battery charger <NUM> charges the battery packs 14A-F in series such that one battery pack 14A-F is charged at a time. The charging circuit <NUM> cycles serially through the charging ports 26A-F to determine parameters regarding the battery packs 14A-F that are connected to each port 26A-F. These parameters include the presence of a battery pack and which, if any, of the battery packs requires charging. If more than one battery pack that requires charging is connected to the charger <NUM>, the charging circuit <NUM> will sequentially charge the battery packs in order from the battery pack connected to the lowest charging port (e.g., the first charging port 26A) to the battery pack connected to the highest charging port (e.g., the sixth charging port 26F). When the charging circuit <NUM> is finished charging the battery pack connected to a particular charging port, the charging circuit <NUM> will move on to charge the battery pack connected to the next charging port, and so on. If a battery pack is not connected to one of the battery ports, or if the battery pack and/or charging port is experiencing an error, the charging circuit <NUM> will skip that particular port and move on to the next sequential charging port.

As shown in <FIG>, the battery charger <NUM> further includes a skip switch <NUM> coupled to the charging circuit <NUM>. The illustrated skip switch <NUM> extends from the upper surface <NUM> of the housing <NUM> adjacent the front side surface <NUM>. In other embodiments, the skip switch <NUM> may be positioned in another location on the charger <NUM> that is accessible to a user. The skip switch <NUM> includes a manual actuator <NUM> that allows a user to skip the battery pack currently being charged and advance to the next battery pack in line. That is, the skip switch <NUM> allows the user to select which battery pack 14A-F is currently being charged to charge the battery packs 14A-F out of order. In the illustrated embodiment, the manual actuator <NUM> is a depressible button. In other embodiments, the manual actuator <NUM> may be a slidable switch or a rotatable knob or dial. In operation, a user manually moves (e.g., depresses, rotates, etc.) the skip switch <NUM> relative to the housing <NUM> to control and select which battery pack 14A-F is currently being charged.

For example, rather than charging the battery packs 14A-F sequentially based on the order of the charging ports 26A-F, the user may depress the actuator <NUM> to stop charging the battery pack currently being charged and begin charging the next battery pack in line. Such action allows the user to interrupt charging of the battery pack currently being charged before charging is complete. The user may depress the actuator <NUM> multiple times to skip multiple charging ports until the desired charging port and battery pack is reached. As discussed above, the LEDs 106A-F indicate to the user which battery pack is currently being charged and which battery packs still need charging to facilitate operating the skip switch <NUM>.

<FIG> is a flowchart that depicts operation of the battery charger <NUM> with the skip switch <NUM>. The charging circuit <NUM> includes a processor and memory to perform the steps outlined in the flowchart. Generally, the charging circuit <NUM> checks if a battery pack is connected to a particular charging port and requires charging. If both of these criteria are 'yes,' the charging circuit <NUM> charges the battery pack until charging is complete. Once charging is complete, the charging circuit <NUM> stops charging the battery pack and increments a counter. The charging circuit <NUM> then checks if a battery pack is connected to the charging port associated with the incremented value of the counter (e.g., the next charging port in line) and if the battery pack requires charging. If, however, the skip switch <NUM> is actuated while the battery pack is charging (or at any other time), charging of the battery pack is stopped and the counter is incremented. The charging circuit <NUM> then moves on to check if a battery pack is connected to the charging port associated with the current value of the counter and if that battery pack requires charging. In the illustrated embodiment, the counter increments between <NUM> and <NUM> (corresponding to the six charging ports 26A-F) before automatically resetting back to <NUM>. In other embodiments, the counter may increment to a smaller or greater value depending on the number of charging ports on the charger <NUM>.

In other embodiments, the battery charger <NUM> includes respective inputs associated with each of the charging ports 26A-F. For example, a single button or switch may be associated with each charging port 26A-F. In such embodiments, the charger <NUM> charges the battery pack connected to the port 26A-F with the button or switch that is currently actuated. If a user wishes to charge a particular battery pack connected to a particular charging port, the user actuates the button or switch associated with that port, and the battery charger <NUM> proceeds to charge that battery pack, irrespective of which other pack is currently being charged. If, on the other hand, a user does not depress one of the buttons or switches, the battery charger <NUM> charges the battery packs in order.

The configurations, shapes, and sizes of the battery packs 14A-F for use with the charger <NUM> described above include but are not limited to the configurations, shapes, and sizes of battery packs that are attachable to and detachable from electrical devices such as power tools, test and measurement equipment, vacuum cleaners, outdoor power equipment, and vehicles. Power tools include, for example, drills, circular saws, jigsaws, band saws, reciprocating saws, screw drivers, angle grinders, straight grinders, hammers, impact wrenches, angle drills, inspection cameras, and the like. Test and measurement equipment includes digital multimeters, clamp meters, fork meters, wall scanners, IR temperature guns, and the like. Vacuum cleaners include stick vacuums, hand vacuums, upright vacuums, carpet cleaners, hard-surface cleaners, canister vacuums, broom vacuums, and the like. Outdoor power equipment includes blowers, chain saws, edgers, hedge trimmers, lawn mowers, trimmers, and the like. Vehicles include, for example, automobiles, motorcycles, scooters, bicycles, and the like.

Claim 1:
A battery charger (<NUM>) comprising:
a housing (<NUM>) including a handle (<NUM>) to facilitate lifting and carrying the battery charger (<NUM>);
a plurality of charging ports (26A-F) coupled to the housing (<NUM>), each charging port (26A-F) configured to connect a battery pack (14A-F) to the battery charger (<NUM>);
a charging circuit (<NUM>) positioned within the housing (<NUM>) and electrically coupled to the plurality of charging ports (26A-F), the charging circuit (<NUM>) operable to charge the battery packs (14A-F) connected to the plurality of charging ports (26A-F) one at a time; and
a plurality of indicator lights (106A-F) coupled to the charging circuit (<NUM>) and respectively associated with one of the plurality of charging ports (26A-F) and indicating an operational status of the associated charging port;
wherein the plurality of charging ports (26A-F) is spaced apart on the housing (<NUM>) such that, when the battery pack (14A-F) is connected to each charging port (26A-F), the battery charger (<NUM>) is balanced around the handle (<NUM>),
wherein the housing (<NUM>) includes four side surfaces (<NUM>, <NUM>, <NUM>, <NUM>) arranged in a generally rectangular pattern, and an upper surface (<NUM>) extending between and arranged generally perpendicular to the four side surfaces (<NUM>, <NUM>, <NUM>, <NUM>), and wherein at least one charging port (26A-F) is positioned on each side surface (<NUM>, <NUM>, <NUM>, <NUM>),
wherein the plurality of charging ports (26A-F) includes six charging ports (26A-F), wherein the first two surfaces of the four side surfaces (<NUM>, <NUM>, <NUM>, <NUM>) located on opposite sides each support two charging ports (26A-F), and wherein the second two of the four side surfaces (<NUM>, <NUM>, <NUM>, <NUM>) located on opposite sides each support one charging port (26A-F),
wherein the handle (<NUM>) extends from and is spaced apart from the upper surface (<NUM>) of the housing (<NUM>),
wherein the indicator lights (106A-F) are supported on the upper surface (<NUM>) beneath the handle (<NUM>), and
wherein the indicator lights associated with the charging ports located on the first two surfaces of the four side surfaces (106A-F) are generally covered by the handle (<NUM>) when the charger (<NUM>) is viewed from above.