as) United States
`a2) Patent Application Publication (10) Pub. No.: US 2005/0046384 Al
`(43) Pub. Date: Mar.3, 2005
`
`Simoeset al.
`
`US 20050046384A1
`
`(54) PORTABLE BATTERY CHARGER
`
`(76)
`
`Inventors: Felipe Oliveira Simoes, Kitchener
`(CA); Dan G. Radut, Waterloo (CA)
`
`(60) Provisional application No. 60/246,142,filed on Nov.
`6, 2000.
`
`Publication Classification
`
`Correspondence Address:
`David B. Cochran, Esq.
`Jones Day
`901 Lakeside Avenue/North Point
`Cleveland, OH 44114 (US)
`
`(21) Appl. No.:
`
`10/443,286
`
`(22)
`
`Filed:
`
`May22, 2003
`
`Related U.S. Application Data
`
`(63) Continuation of application No. 10/007,848, filed on
`Nov. 5, 2001, now Pat. No. 6,583,601.
`
`(51) Unt. C07 caccccssssnssssnssstnssstvesnetnsneee H02J 7/00
`(52) US. Cd.
`ceecscsssssssnssstnssetnsistsesnttetnetesnee 320/114
`
`(57)
`
`ABSTRACT
`
`A portable battery charger for a mobile device having a
`rechargeable battery includes battery contacts, a switching
`regulator, and a charger interface. The battery contacts are
`configured to receive a battery having a low-voltage value.
`The switching regulator is coupled to the battery contacts
`and configured to draw the low-voltage value from the
`battery and convert
`the low-voltage value to a charger
`output. The charger interface is configured to electrically
`engage the mobile device andis further configured to couple
`the charger output from the switching regulator to the
`rechargeable battery in the mobile device.
`
`ANALOG SWITCH
`
`SWITCHING
`REGULATOR
`
`REVERSE
`BATTERY
`PROTECTION
`
`CONNECTOR
`
`CONTROL
`MONITOR
`
`CHARGER
`INTERFACE
`
`1
`
`APPLE 1115
`Apple v. GUI
`IPR2021-00470
`
`APPLE 1115
`Apple v. GUI
`IPR2021-00470
`
`1
`
`

`

`US 2005/0046384 Al
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`4399VH3
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`yolv7n93u
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`ONTH31IMS
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`Patent Application Publication Mar. 3,2005 Sheet 1 of 4 |bis
`33gy3INIh—~soyINOD—ISUIABY
`40AM3LLVE.
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`LINOW
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`NOTL93108d
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`HILIMSSOTWNY
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`2
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`

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`Patent Application Publication Mar. 3, 2005 Sheet 2 of 4
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`US 2005/0046384 Al
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`3
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`4
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`US 2005/0046384 Al
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`Sheet 4 of 4
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`Patent Application Publication Mar. 3, 2005
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`5
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`US 2005/0046384 Al
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`Mar. 3, 2005
`
`PORTABLE BATTERY CHARGER
`
`CROSS-REFERENCE TO RELATED
`APPLICATION
`
`[0001] This application is a continuation of US. applica-
`tion Ser. No. 10/007,848,
`entitled “Portable Battery
`Charger,” filed Nov. 5, 2001, which claims priority from
`USS. Provisional Application No. 60/246,142, entitled “Por-
`table Battery Charger,” filed Nov. 6, 2000. Both of these
`prior applications are incorporated herein by reference.
`
`BACKGROUND
`
`[0002]
`
`1. Field of the Invention
`
`[0003] This invention relates to battery chargers. Particu-
`larly, the invention relates to portable battery chargers for
`use with mobile communication devices.
`
`[0004]
`
`2. Description of the Related Art
`
`[0005] Manyelectronic devices, such as mobile commu-
`nication devices, are powered by rechargeable batteries.
`Typically,
`rechargeable batteries
`include Lithium-ion
`(Lilon) and Nickel Cadmium (NiCad) cells.
`Instead of
`powering downthe device and replacing the rechargeable
`battery, these electronic devices are typically plugged into a
`battery charger when the rechargeable battery is in a low
`charge state. Battery chargers typically include a cord that
`plugsinto an electrical wall outlet and the electronic device.
`
`SUMMARY
`
`[0006] A portable battery charger for a mobile device
`having a rechargeable battery includes battery contacts, a
`switching regulator, and a charger interface. The battery
`contacts are configured to receive a battery having a low-
`voltage value, that is, less than a rechargeable battery’s fully
`charged value. The switching regulator is coupled to the
`battery contacts and configured to draw power from the
`low-voltage battery and convert the low-voltage input to a
`charger output. The charger interface is configured to elec-
`trically engage the mobile device and is further configured
`to couple the charger output from the switching regulator to
`the rechargeable battery in the mobile device.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0007] FIG. 1 is a block diagram of a portable charger
`circuit;
`
`[0008] FIG. 2 is an orthogonal view of the front of a
`portable charger;
`
`[0009] FIG. 3 is an orthogonal view of the back of the
`portable charger;
`
`[0010] FIG. 4A is an orthogonal view of the back of the
`portable charger with a battery door cover removed;
`
`FIG.4B is an orthogonal view similar to FIG. 4A
`{0011]
`with a battery installed; and
`
`[0012] FIG. 5 is an orthogonal view of the portable
`charger connected to a portable electronic device.
`
`DETAILED DESCRIPTION
`
`[0013] Referring now to the drawing figures, FIG. 1 is a
`block diagram of a portable charger circuit 10. The charger
`
`circuit 10 includes a low-voltage battery 11 and first and
`second battery contacts 12 and 13, which provide power to
`the charger circuit 10. A reverse battery protection module
`14, an analog switch 16, a switching regulator 18, and a
`control and monitor module 20 operate together to transform
`the charge in the low voltage battery 11 into a charger output
`24. A charger interface connector 22 communicates with a
`mobile device 23 having a rechargeable battery 25. The
`battery 11 inserted between the battery contacts 12 and 13
`charges the rechargeable battery 25 (such as a Lilon cell
`battery) in the mobile device 23 through the charger inter-
`face connector 22.
`
`[0014] The battery contacts 12 and 13 are coupled in
`parallel with the reverse battery protection module 14. In
`addition, one of the battery contacts 12 is also coupled to the
`switching regulator 18, and the other battery contact 13 is
`coupled both to the switching regulator 18 and the charger
`interface 22 through the analog switch 16. The analog switch
`16 receives a control signal 15 from the reverse battery
`protection module 14 that can open the analog switch 16 in
`order to decouple the battery 11 from the chargercircuit 10.
`The switching regulator 18 generates the charger output 24,
`which is fed back to the reverse battery protection module
`14, and which is also coupled to the charger interface
`connector 22. The control and monitor module 20 commu-
`
`nicates with the switching regulator 18 and the charger
`interface connector 22 through control signals 26 and 28.
`The charger interface connector 22 preferably communi-
`cates to the mobile device 23 through a serial connection,
`such as a 16-pin miniature connector.
`
`[0015] Preferably, one of the battery contacts 12 is a
`positive terminal and the other battery contact 13 is a
`negative terminal. Whena battery 11 is inserted between the
`battery contacts 12 and 13, the reverse battery protection
`module 14 detects whether the battery 11 is inserted cor-
`rectly by checking the polarity of the battery 11. If the
`battery polarity is reversed, then the control signal 15 from
`the reverse battery protection module 14 opens the analog
`switch 16, thereby decoupling the negative terminal 13 from
`the switching regulator 18 and charger interface connector
`22. The reverse battery protection module 14 thus protects
`the circuit 10 from reverse polarity that could occur if a
`battery 11 was inserted incorrectly. By maintaining the
`analog switch 16 in the off (open) position,
`the reverse
`battery protection module 14 prevents any charge from the
`battery 11 from leaking to the switching regulator 18, or to
`other components in the circuit 10.
`
`[0016] The reverse battery protection module 14 also
`monitors the charge line to turn the analog switch 16 on in
`the presence of an operational rechargeable battery.
`
`If the battery 11 is installed correctly between the
`[0017]
`contacts 12 and 13,
`then the switching regulator 18 is
`preferably powered from a low-voltage value battery 11 and
`provides powerto the charger output 24, which is used to
`charge the rechargeable battery 25 in the mobile device 23.
`The switching regulator 18 preferably operates in one of two
`different modes depending on the voltage of the recharge-
`able battery 25 in the mobile device 23. When the recharge-
`able battery voltage is low, then the switching regulator 18
`preferably operates in a current limiting mode. In this mode,
`the switching regulator 18 generates a constant current
`output 24 through the charger interface connector 22 to the
`
`6
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`US 2005/0046384 Al
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`Mar. 3, 2005
`
`mobile device 23. The rechargeable battery 25 is charged
`from this constant current output 24 until the rechargeable
`battery 25 reaches a threshold voltage, which dependson the
`Lilon battery voltage. Once the threshold voltage is reached,
`then the switching regulator 18 preferably switches to a
`constant voltage mode. In the constant voltage mode, the
`switching regulator 18 preferably generates a constant volt-
`age output 24 to charge the rechargeable battery 25. As the
`rechargeable battery 25 voltagerisesto its final charge value,
`that is, the rechargeable battery is fully charged, the feed-
`back signal 28 from the mobile device 23 is used to regulate
`the output of the switching regulator 18 in order to keep the
`voltage constant at the rechargeable battery 25 terminals.
`
`[0018] The differing modes for charging the rechargeable
`battery 25 are provided in orderto achieve efficient recharg-
`ing. When the charger circuit 10 is in the current limiting
`mode, the switching regulator 18 preferably generates a full
`duty cycle charger output 24. Thus, when the voltage of the
`rechargeable battery 25 is below the threshold level,
`the
`rechargeable battery 25 is charged on a full duty cycle. Once
`the threshold voltage is reached, however, the voltage of the
`battery 11 is no longer sufficient to charge the rechargeable
`battery 25, and the switching regulator 18 switches to a
`constant voltage modeto increase the voltage of the charger
`output 24. The control and monitor module 20 monitors the
`feedback signal 28 to determine the voltage of the recharge-
`able battery 25. As the rechargeable battery voltage exceeds
`the threshold voltage, the control and monitor module 20
`controls the output voltage of the charger output 24. As the
`rechargeable battery voltage increases,
`the control and
`monitor module 20 increases the voltage of the charger
`output 24 in order to continue to charge the rechargeable
`battery 25.
`
`[0019] The control and monitor module 20 monitors sig-
`nals 26 and 28 from the switching regulator 18 and the
`mobile device to control the operation of the circuit 10. For
`example, the control and monitor module 20 may monitor
`the voltages of the charger battery 11 and the rechargeable
`battery 25, and control signals from the mobile device 25.
`The control and monitor module 20 monitors the charger
`battery 11 to determine when the voltage of the battery is
`below 1.0 V. When the voltage is below 1.0 V, the control
`and monitor module 20 sends a signal to the switching
`regulator 18 to shut it down in order to prevent damage to
`the switching regulator 18. The control and monitor module
`20 may also send a signal to the mobile device 25 to report
`the low voltage to a user of the device so that the user can
`replace the charger battery 11. As described above,
`the
`control and monitor module 20 may also monitor
`the
`rechargeable battery voltage to determine when to switch
`modes on the switching regulator 18, and to turn off the
`switching regulator 18 when the rechargeable battery 25
`reaches a desired voltage level.
`
`[0020] The voltage of the rechargeable battery 25 is moni-
`tored by the control and monitor module 20 through the
`charger interface connector 22 as an analog feedback signal
`28. The control and monitor module 20 monitors the feed-
`
`back signal 28 to determine whento send a control signal 26
`to the switching regulator 18 to change modes from current
`limiting to constant voltage. This signal is preferably sent to
`the switching regulator 18 when the feedback signal 28 is
`around the threshold value. The control and monitor module
`
`20 then monitors the feedback signal 28 to ramp up the
`
`charger output 24 as the rechargeable battery 25 is charged
`to the final desired voltage level (fully charged). The switch-
`ing regulator 18 thus produces an output signal 24 at a
`voltage that is higher than the voltage of the rechargeable
`battery 25. The charging continues until the rechargeable
`battery 25 is fully charged (around 4.1 V), or the charger
`battery voltage drops to 1.0 V. If the charger battery voltage
`drops to 1.0 V, then the control and monitor module 20 may
`send a signal to the mobile device 23, which can notify a
`user that the charger battery 11 is in a low voltagestate, and
`charging has stopped. The control and monitor module 20
`thus monitors the charge in both batteries to determine how
`to charge the rechargeable battery 25 from the charger
`battery 11.
`
`the
`[0021] For example, when a user determines that
`rechargeable battery 25 in the mobile device 23 is in a low
`charge state, then the user connects the charging circuit 10
`to the mobile device 25. The control and monitor module 20
`
`detects the presence of the mobile device 25 and also detects
`the presence of the charger battery 11 in the charger circuit
`10. The control and monitor module 20 then directs the
`
`switching regulator 18 to begin generating the charger
`output 24. Assuming the rechargeable battery 25 is in a
`charge state with a voltage below the final fully charged
`state, the control and monitor module 20 directs the switch-
`ing regulator 18 to charge in current limiting mode. The
`control and monitor module 20 then monitors both batteries
`11 and 25 for changes in their respective terminal voltages.
`Whenthe rechargeable battery 25 is charged to a state where
`its voltage equals the final fully charged state,
`then the
`control and monitor module 20 switches the switching
`regulator 18 to the constant voltage mode. The control and
`monitor module 20 provides the voltage level of the
`rechargeable battery 25 to the switching regulator 18 so that
`the charger output 24 is regulated to keep the voltage
`constant at the rechargeable battery 25 terminals. The con-
`trol and monitor module 20 then sends a shutdownsignal to
`the switching regulator 18 when the voltage of the charger
`battery 11 is below 1.0 V,or the rechargeable battery 25 is
`fully charged. In an alternative embodiment, other control
`signals 28 from the mobile device 23 mayalso shut downthe
`charging operation. For example, a temperature monitor on
`the mobile device 23 may generate a shutdownsignalif the
`rechargeable battery 25 overheats during charging.
`
`[0022] FIG. 2 is an orthogonal view of the front of a
`portable battery charger 30. The battery charger 30 includes
`a generally rectangular housing 32. The housing includes a
`front wall 34, a back wall 36 and side walls 38. The back and
`side walls 36 and 38 extend past an edge 40 of the front wall
`34 to form a well 42. The well 42 receives and mates with
`the mobile device 70 (FIG.5). Side wall guides 44 guide the
`edges of the mobile device 70 into the well 30. An edge
`surface guide 46 of the back wall 36 guides the back of the
`mobile device 70 into the well 42. The guides 44 and 46
`direct a pin connector on the mobile device 70 to mate with
`a connector 50 on the battery charger 30. The connector 50
`may, for example, be the charger interface connector 22
`described above with reference to FIG. 1. In this example,
`the connector 50 is a male pin connector, but other connec-
`tors on the battery charger 30 could instead include a female
`pin connector configured to mate with a male pin connector
`on the mobile device.
`
`7
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`

`

`US 2005/0046384 Al
`
`Mar. 3, 2005
`
`[0023] Prongs 54 engagethe sides of the mobile device 23
`so that the portable charger 30 is supported on the device
`through the prongs 54 instead of being supported through
`the pin connector 50. The prongs 54 preferably snap into
`notches in the side of the mobile device 70 such that an
`interference fit is achieved between the prongs 54 and the
`notches that can support the weight of the portable charger
`26. The portable charger 30 can preferably be removed from
`the mobile device 70 by sliding the portable charger 30 away
`from the mobile device 70. The prongs 54 flex away from
`the sides of the mobile device 70 when the charger 30 is slid
`away from the mobile device 70.
`
`[0024] FIG. 3 is an orthogonal view of the back of the
`portable battery charger 30. A battery cover 58 is slidably
`received on the back 36 of the portable charger 30. The
`battery cover 58 slides into place and is retained by an
`interference fit between the battery cover 58 and the back 36.
`FIG.4A is an orthogonal view of the back of the portable
`charger 30 with the battery cover 58 removed. A battery
`compartment 60 includes battery guides 62, a positive
`contact 64, and a negative contact spring 66. The positive
`contact 64 and the negative contact spring 66 may, for
`example, be the battery contacts 12 and 13 described above
`with reference to FIG. 1. These components 62, 64, and 66
`guide a battery so that the battery may be properly seated in
`the battery compartment 60. FIG. 4B is an orthogonal view
`of the back of the portable charger 30 with the battery door
`cover 50 removed, and a battery 68 inserted in the battery
`compartment 60.
`
`[0025] FIG. 5 is an orthogonal view of the portable
`charger 30 connected to a portable electronic device 70.
`Whenattached to the mobile device 70, the portable charger
`30 preferably extends from the base of the mobile device 70.
`A.user can then carry both the portable charger 30 and the
`mobile device 70 so that the user may use the mobile device
`70 as the portable charger 30 is charging the Lilon battery
`in the mobile device 70.
`
`[0026] The embodiment described above is an example of
`structures or methods having elements corresponding to the
`elements recited in the claims. This written description may
`enable those skilled in the art to make and use embodiments
`
`having alternative elements that likewise correspond to the
`elements of the invention recited in the claims. The intended
`
`scope of the invention thus includes other structures or
`methods that do not differ from the literal language of the
`claims, and further includes other structures or methods with
`insubstantial differences from the literal language of the
`claims.
`
`1. A communication apparatus, comprising:
`
`a mobile communication device having a rechargeable
`battery; and
`
`a portable battery recharging unit detachably coupled to
`the mobile communication device for recharging the
`rechargeable battery, the portable battery recharging
`unit comprising:
`
`a housing;
`
`a battery fitted within the housing;
`
`a switching regulator coupled to the battery for gener-
`ating a charging output; and
`
`a charging interface coupling the charging output from
`the switching regulator to the rechargeable battery
`within the mobile communication device in order to
`recharge the rechargeable battery.
`2. The communication apparatus of claim 1, wherein the
`mobile communication device includes an interface that
`electrically mates to the charging interface for receiving the
`charging output from the voltage regulator.
`3. The communication apparatus of claim 1, wherein the
`battery is a AA-type battery.
`4. The communication apparatus of claim 1, wherein the
`switching regulator is a voltage regulator.
`5. The communication apparatus of claim 1, wherein the
`switching regulator is configured to operate in two modes,a
`current limiting mode and a constant voltage mode.
`6. The communication apparatus of claim 5, wherein the
`switching regulator operates in the current limiting mode
`until a threshold voltage is measured on the rechargeable
`battery and then switches to the constant voltage mode
`thereafter.
`
`7. The communication apparatus of claim 6, wherein the
`threshold voltage is approximately 2.5 volts.
`8. The communication apparatus of claim 1, wherein the
`portable battery recharging unit further comprises: a con-
`troller, coupled to the charger interface and the switching
`regulator, for controlling the operation of the switching
`regulator based on one or more signals received from the
`mobile communication device.
`
`9. The communication apparatus of claim 8, wherein the
`one or moresignals includes a voltage level signal indicating
`the voltage of the rechargeable battery.
`10. The communication apparatus of claim 8, wherein the
`one or more signals includes a temperature level signal
`indicating the temperature of the rechargeable battery.
`11. The communication apparatus of claim 1, wherein the
`portable battery recharging unit further comprises: a con-
`troller, coupled to the battery and the switching regulator, for
`turning on or off the switching regulator based on the voltage
`level of the battery.
`12. The communication apparatus of claim 11, wherein
`the controller is further coupled to the charging interface,
`and provides a low voltage battery signal to the mobile
`communication device through the charging interface when
`the voltage of the battery drops below a predetermined low
`voltage threshold level.
`13. The communication apparatus of claim 12, wherein
`the low voltage threshold level is approximately 1.0 volts.
`14. The communication apparatus of claim 1, wherein the
`rechargeable battery is a Nickel Cadmium battery.
`15. The communication apparatus of claim 1, wherein the
`rechargeable battery is a Lithium Ion battery.
`16. The communication apparatus of claim 1, wherein the
`portable battery recharging unit further comprises: a reverse
`battery protection circuit coupled between the battery and
`the switching regulator for decoupling the battery from the
`switching regulator if the reverse battery protection circuit
`detects that the battery is incorrectly installed in the housing.
`17. The communication apparatus of claim 1, wherein the
`housing of the portable battery recharging unit comprises a
`well having side wall guides and an edge surface guide that
`slidably receive and mate the mobile communication device
`to the portable battery charger.
`
`8
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`

`US 2005/0046384 Al
`
`Mar. 3, 2005
`
`18. The communication apparatus of claim 17, wherein
`the housing further comprises a pair of fasteners that detach-
`ably fasten the portable battery recharging unit to the mobile
`communication device.
`
`19. The communication apparatus of claim 18, wherein
`the pair of fasteners are a pair of prongs located on the side
`wall guides.
`20. The communication apparatus of claim 19, wherein
`the pair of prongs snap onto the mobile communication
`device to provide an interference fit between the prongs and
`the mobile communication device that supports the weight
`of the portable battery recharging unit.
`21. The communication apparatus of claim 20, wherein
`the pair of prongs snap onto a correspondingpair of notches
`on the mobile communication device.
`
`22. The communication apparatus of claim 1, wherein the
`housing of the portable battery recharging unit includes a
`battery cover which covers a battery compartmentthat holds
`the battery, wherein the battery is removable from the
`portable battery recharging unit by detaching the battery
`cover from the housing.
`23. The communication apparatus of claim 1, wherein the
`portable battery recharging unit further comprises: a con-
`troller, coupled to the rechargeable battery and the battery,
`for controlling the operation of the switching regulator based
`on the measured voltage level of both the rechargeable
`battery and the battery.
`24. The communication apparatus of claim 1, wherein the
`mobile communication device is operable while the portable
`battery recharging unit is recharging the rechargeable battery
`of the mobile communication device.
`
`25. A method of charging a rechargeable battery in a
`mobile communication device using a portable battery
`charger, comprising the stepsof:
`
`physically and electrically coupling the portable battery
`charger to the mobile communication device;
`
`receiving a low voltage source of energy from a battery
`within the portable battery charger;
`
`converting the low voltage source of energy to a charging
`output using a switching regulator in the portable
`battery charger; and
`
`recharging the rechargeable battery by applying the charg-
`ing output
`to the rechargeable battery through the
`electrical coupling of the portable battery charger and
`the mobile communication device.
`
`26. The method of claim 25, further comprising the steps
`
`operating the switching regulator in a current limiting
`mode until a threshold voltage is measured on the
`rechargeable battery and then operating the switching
`regulator in a constant voltage mode thereafter.
`27. The method of claim 25, further comprising the step
`
`of:
`
`of:
`
`operating the switching regulator based upon one or more
`signals
`received from the mobile communication
`device.
`
`28. The method of claim 27, wherein the one or more
`signals includes a voltage level signal indicating the voltage
`of the rechargeable battery.
`
`29. The method of claim 27, wherein the one or more
`signals includes a temperature level signal indicating the
`temperature of the rechargeable battery.
`30. The method of claim 25, further comprising the step
`of:
`
`operating the switching regulator based upon the voltage
`level of the battery.
`31. The method of claim 25, further comprising the step
`of:
`
`to the mobile
`providing a low voltage battery signal
`communication device when the voltage level of the
`battery drops below a predetermined low voltage
`threshold level.
`
`32. The method of claim 25, further comprising the steps
`of:
`
`detecting if the battery is incorrectly installed in the
`portable battery charger, and if so, then decoupling the
`battery from the switching regulator.
`33. An apparatus for charging a rechargeable battery in a
`mobile communication device using a portable battery
`charger, comprising:
`
`means for physically and electrically coupling the por-
`table battery charger to the mobile communication
`device;
`
`means for receiving a low voltage source of energy from
`a battery within the portable battery charger;
`
`means for converting the low voltage source of energy to
`a charging output; and
`
`meansfor recharging the rechargeable battery by applying
`the charging output to the rechargeable battery through
`the electrical coupling of the portable battery charger
`and the mobile communication device.
`
`34. The apparatus of claim 33, wherein the means for
`converting includes a switching regulator,
`the apparatus
`further comprising:
`
`means for operating the switching regulator in a current
`limiting mode until a threshold voltage is measured on
`the rechargeable battery and then operating the switch-
`ing regulator in a constant voltage mode thereafter.
`35. The apparatus of claim 33, further comprising:
`
`means for operating the switching regulator based upon
`one or more signals received from the mobile commu-
`nication device.
`
`36. The apparatus of claim 35, wherein the one or more
`signals includes a voltage level signal indicating the voltage
`of the rechargeable battery.
`37. The apparatus of claim 35, wherein the one or more
`signals includes a temperature level signal indicating the
`temperature of the rechargeable battery.
`38. The apparatus of claim 33, further comprising:
`
`means for operating the switching regulator based upon
`the voltage level of the battery.
`39. The method of claim 33, further comprising:
`
`means for providing a low voltage battery signal to the
`mobile communication device when the voltage level
`of the battery drops below a predetermined low voltage
`threshold level.
`
`9
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`

`US 2005/0046384 Al
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`Mar. 3, 2005
`
`40. The apparatus of claim 33, further comprising:
`
`means for detecting if the battery is incorrectly installed
`in the portable battery charger, and if so, then decou-
`pling the battery from the switching regulator.
`41. An apparatus, comprising:
`
`a mobile device having a rechargeable battery; and
`
`a battery charging device detachably connected to the
`mobile device, the battery charging device including:
`
`battery contacts configured to receive a battery;
`
`a switching regulator coupled to the battery contacts
`and configured to draw a voltage from the battery
`and convert the voltage to a charger output; and
`
`a charger interface configured to electrically engage the
`mobile device and further configured to coupled the
`charger output from the switching regulator to the
`rechargeable battery in the mobile device.
`42. The apparatus of claim 41, wherein the battery con-
`tacts are configured to engage a AA battery.
`43. The apparatus of claim 41, wherein the switching
`regulator is configured to operate in a first mode and a
`second mode, wherein the first mode is a current limiting
`mode.
`
`44. The apparatus of claim 43, wherein the switching
`regulator generates a full duty cycle charger output when
`operating in the current limiting mode.
`45. The apparatus of claim 43, wherein the second mode
`is a constant voltage mode.
`46. The apparatus of claim 43, wherein the battery charg-
`ing device further includes a control and monitor module
`coupled between the switching regulator and the charger
`interface and configured to control the charger output.
`47. The apparatus of claim 46, wherein the control and
`monitor module is configured to switch the switching regu-
`
`lator from the first mode to the second mode when the
`voltage of the rechargeable battery is above a threshold
`voltage.
`48. The apparatus of claim 47, wherein the threshold
`voltage is 2.5 V.
`49. The apparatus of claim 46, wherein the control and
`monitor module monitors the voltage on the battery in order
`to turn the switching regulator off when the voltage of the
`battery is insufficient to charge the rechargeable battery.
`50. The apparatus of claim 49, wherein the control and
`monitor module is configured to send a shutdownsignal to
`the switching regulator when the voltage of the battery drops
`below a threshold voltage.
`51. The apparatus of claim 50, wherein the threshold
`voltage is 1.0 V.
`52. The apparatus of claim 49, wherein the control and
`monitor module is configured to send a low battery value to
`the mobile device when the voltage of the battery drops
`below a threshold voltage.
`53. The apparatus of claim 41, wherein the rechargeable
`battery is a lithium ion battery.
`54. An apparatus, comprising:
`
`a mobile device having a rechargeable battery; and
`
`a battery charging device detachably connected to the
`mobile device, the battery charging device including:
`
`means for connecting the battery charging device to a
`battery;
`
`means for drawing a voltage from the battery and
`converting the voltage to a charger output; and
`
`means for coupling the charger output to the recharge-
`able battery in the mobile device.
`*
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