Abstract: A timed electric battery charger 10 for the processing of non-lithium, small appliance and utility batteries 19 through a charging cycle comprising a current source having an alternating current input 11 and a direct current output 14 and a timer 16 for dividing the charging cycle into a plurality of successive, predetermined phases, each phase comprising a duty cycle wherein a charging current is delivered to the battery, alternated with a resting cycle during which a charging current is not delivered to the battery.

Abstract: Provided is a method for increasing the cycle life of discharged lithium electrochemical cells, wherein the cell comprises (i) an anode comprising lithium; (ii) a cathode comprising an electroactive sulfur-containing material; and (iii) a liquid electrolyte interposed between the anode and cathode; wherein the method comprises the steps of: (a) charging the cell at an initial low rate of less than 0.2 mA/cm2 to a cell voltage in the range of 2.1 to 2.3 V followed by (b) a subsequent high rate of greater than 0.2 mA/cm2 to a cell voltage of at least 2.4 V.

Abstract: A compact, economical and fast battery charger for Ni-CAD and Ni-MH batteries turns a current source into a controlled voltage source which keys off a signal representative of the voltage level of the battery during the charging process and turns the current source ON and OFF to assure that the battery during the charging process does not exceed a given voltage level. The apparatus includes in par a ballasting resistor in series with the battery to compensate for the low resistance of the battery and an open collector voltage comparator which establishes high and low voltage set points for turning the current source ON and OFF at the appropriate times. The method and apparatus includes a visual display responsive to a signal which produces on the visual display an indication of the state of charge of the battery during a charging cycle. A circuit board has a long U-shaped trace extending around a notch in the board, on each side of each is mounted on battery.

Abstract: A method of charging a rechargeable battery which comprises charging the battery with a charging current; sampling conditions of the battery during charging to recognize potential adverse conditions within the battery; interrupting the charging current periodically to create current-free periods and sampling an open circuit voltage of the battery during each current-free period to identify potential overcharge conditions in the battery; lowering the charging current if any adverse conditions are identified and continuing charging with the charging current if adverse charging conditions are not identified; and terminating charging when a predetermined value is recognized. The method of charging nickel-metal hydride and nickel-cadmium batteries is based on switching charging current as soon as temperature related battery open circuit voltage reaches the first predetermined value, tapering current and continuing charging up to terminating point.

Abstract: This invention is a single wire interface communication system whereby a phone having internal charging circuitry communicates the charging status of the battery attached to the phone by varying the duty cycle of a pulse with a predetermined period across the single wire interface. In a preferred embodiment, the predetermined pulse of time T, where T is 1 second, is divided into N divisions, where N equals 10. A duty cycle high for time T/N and low for time 9T/N represents a first charging state; a duty cycle high for time 2T/N and low for time 8T/N corresponds to a second charging state; and so on. The system allows for information to be transmitted across a single wire, thereby freeing data connections for other accessories.

Abstract: A method for charging a secondary battery by measuring the static/open circuit voltage and comparing it to a predetermined value includes: a first step of precharging the secondary battery; thereafter pausing a predetermined interval; a step of measuring a secondary battery voltage Vba1 after performing the pausing; and a step of charging the secondary battery based on the measurement of the secondary battery voltage Vba1.

Abstract: The method of charging a plurality of batteries uses a charging power supply to pulse charge a plurality of batteries to full charge by time-division switching of the battery being charged. Further, this charging method moves timing intervals forward to begin charging the next battery when charging of a fully charged battery is stopped.

Abstract: A method of charging a battery, and particularly a nickel battery, in a mobile charger, such as a vehicular charger, which is subjected to elevated temperatures. The method includes the steps of a first charging of the battery until a temperature inflection occurs, and then ceasing the charging while the battery temperature stabilizes. Then the battery is charged a second time, and a parameter is monitored for an indication of a full charge, such as temperature inflection or voltage cut-off. Preferably, when the battery reaches an elevated temperature, the charging is ceased until the battery stabilizes, and the charger monitors either temperature inflection, voltage cut-off, or a Coulomb count to determine when the battery has a full charge.

Abstract: A voltage/current regulator regulates charging of a rechargeable battery in a portable apparatus that includes a transistor and a controller means coupled to the transistor for controlling the charging current to the battery. The controller determines the power dissipation in the transistor of the regulator. If the power dissipation is above a maximum allowed power dissipation, the controller decreases the charging current by a particular current step. Otherwise, the controller determines if the power dissipation will exceed the maximum allowed power dissipation if the charging current is increased by the current step. If not, the controller increases the charging current by the current step.

Abstract: A circuit for providing hi-Z charging of a deeply discharged battery includes a load simulator circuit to provide a charging load resistance even when the battery has been discharged to 0V. The load simulator circuit includes a transistor connected in series with the battery. A logic circuit detects when the battery voltage is below a minimum threshold voltage and instructs a voltage control circuit to provide a constant voltage across the battery and the load simulator circuit. The logic circuit also applies the output of a current control circuit to the gate terminal of the transistor, enabling the current control circuit to regulate the total resistive load of the battery-transistor pair and thus maintain a constant hi-Z charge current across the battery.

Abstract: An engine stopping/starting control unit having improved accelerating performance. A charging limiting device is provided which limits the charge provided to a generator when the vehicle is stopped. The decreased charging allows for better performance when the vehicle accelerates from a stopped states. Also, the vehicle headlight can be dimmed while the vehicle is stopped, which reduces the load on the generator. An acceleration detector detects when the vehicle accelerates during running, and can decrease the generator load in response to the acceleration.

Abstract: An apparatus and method for fast battery charging are provided. A fast battery charger applies high charging current to a battery to minimize charging time. Micropeak detection of the battery voltage prevents overcharging of the battery cells, thereby preventing degradation of battery capacity over time. Noise reduction throughout the system as well as improved detection resolution allows for micropeak detection. A linear power supply eliminates switch noise. The sampling frequency is synchronized with the power supply, eliminating error due to power supply variation. Sleeping sampling is performed to overcome noise due to operation of the CPU. Improved measurement resolution is obtained via a 10-bit analog to digital converter. A subtraction technique maintains the high measurement resolution.

Abstract: In order to create a method with which, independently of the technology of the batteries utilized, a constant overcharging of the batteries is dependably avoided, even given a different capacity, particularly given a value deviating from the original capacity, and, thus, a long service life of the batteries can be assured, it is provided that an initial charging phase of the batteries after initial insertion into the device up to full charging is provided, that, subsequently, the batteries are at least partly discharged and a value representing the previously drawn capacity is generated at every point in time, that this generated value is compared at the beginning of a renewed charging phase with a stored base value representing the duration of the initial charging phase, and that subsequent charging phases follow whose duration is equal to that of the initial charging phase when the generated value is less than or equal to the base value or that subsequently charging phases follow whose duration is determine

Abstract: A power management system for a PC card is disclosed. The power management system allows for a detachable battery pack to be used on a PC card. The PC card can select power from the personal computer or from the detachable battery pack. In one embodiment, power can also be selected from a DC wall adaptor, which can be connected to the PC card or battery pack. In another embodiment, the power controller on the PC card is always powered by the personal computer, so that the power management system can work even when a detachable battery pack is low in power or not connected to the PC card. The battery pack can be recharged from the DC wall adaptor or from the personal computer.

Abstract: An external universal battery charging apparatus which can include external universal battery charger circuitry having at least one universal battery charger circuitry input and at least one universal battery charger circuitry output. The universal battery charger circuitry output can include at least one battery charger output, which itself can include at least one universal battery connector and at least one universal battery charger cable. The at least one universal battery charger circuitry output can include at least one adapter pass through output, which itself can include at least one connector adapted to operably connect to an electronic device. The external universal battery charger circuitry can include at least one battery recognition and parameter adjustment circuit, battery current parameter adjustment circuit, charged voltage parameter adjustment circuit, and maximum power draw parameter adjustment circuit.

Abstract: An optimizer circuit is interposed between a DC bus and a battery of a power supply system, including two converters in parallel, one that can lower the battery voltage below the bus voltage or directly connect the bus to the battery and one that can raise the voltage to the battery above the bus voltage. A controller actuates the two converters for optimizing battery charging and maintenance and for providing the battery power to the bus if other sources supplying the bus are not available.

Abstract: In a battery charging device, an ECU (30) has: an ordinary charge control section (34) adapted to charge a battery (12) in an ordinary charge mode; an under charge control section (36) adapted to charge a battery (12) in an under charge mode; and mode switching controller (38) which switch the output paths of the ordinary charge control section (34) and the under charge control section (36), thereby to select one of the charge modes.

Abstract: A compact, economical and fast battery charger for Ni-CAD and Ni-MH batteries turns a current source into a controlled voltage source which keys off a signal representative of the voltage level of the battery during the charging process and turns the current source ON and OFF to assure that the battery during the charging process does not exceed a given voltage level. The apparatus includes in par a ballasting resistor in series with the battery to compensate for the low resistance of the battery and an open collector voltage comparator which establishes high and low voltage set points for turning the current source ON and OFF at the appropriate times. The method and apparatus includes a visual display responsive to a signal which produces on the visual display an indication of the state of charge of the battery during a charging cycle. A circuit board has a long U-shaped trace extending around a notch in the board, on each side of each is mounted on battery.

Abstract: A control circuit is provided to minimize the charging cycle time of a battery charging system by maximizing the length of time that high constant charging current is applied to a discharged battery. The control circuit includes a constant current (CC) error amplifier, a constant voltage (CV) error amplifier, an output amplifier, and two pole-splitting compensation networks. The control circuit works in conjunction with a power source to charge a secondary battery. The pole-splitting compensation networks allow the CC, CV, and output amplifiers to be configured for high gain, without sacrificing output stability. The control circuit provides a sharp transition between the CC mode and CV mode of operation. In the CC mode, fast bulk battery charging is provided. In the CV mode, the control circuit initially provides a "top-off" charge to the battery and subsequently safely maintains the battery at its fully charged state.

Abstract: A method for charging a rechargeable battery pack includes providing a charger having first and second charging processes, and manually selecting one of the first and second charging processes. The charging method may include a step for indicating status or end of the selected one charging process. The first charging process may include the steps of providing a fast charging current, indicating end of the fast charging current and providing an equalization current. The second charging process may include the steps of providing a fast charging current, subsequently providing an equalization current and indicating end of equalization current. The second charging process may also include a temperature checking step. Further disclosed is a battery charging apparatus including a charger for charging a battery and having first and second charging processes, and a switch connected to the charger for manually selecting one of the first and second charging processes. The charger may include a microprocessor.

Abstract: Disclosed is a device and method for charging an electric car battery pack that charges by receiving power and discharges to supply power. A battery charging controller controls charging the battery pack at a constant power, and when the voltage of the battery pack is over a first voltage, controls a constant current charging process, and after this, each time a peak value of the battery pack is over a second voltage, controls a sequential reduction of current and performs a constant current charging process, and when the voltage of the battery pack is over a third voltage, controls a constant current charging process at a fourth voltage, and when the charging voltage is over a fifth voltage, controls a termination of the charging process. A battery charger receives external power according to the control of the battery charging controller, and charges the battery.

Abstract: This invention combines linear charging techniques with ionic relaxation pulse charging to rapidly charge lithium ion batteries to full capacity. The preferred embodiment incorporates a blocking diode and series resistor to multiplex an ionic relaxation control circuit with a linear regulated charging circuit, thereby utilizing a single, common, shared power transistor.

Abstract: A portable phone has an internal battery and an external battery pack that is releasably attachable to the phone. A control unit in the phone controls connection of the respective batteries to a phone power input, depending on the detection of the external battery voltage. Whenever an external battery is present with a voltage above a predetermined minimum value, the external battery will be connected to the phone power input to provide power to operate the phone, so that the internal battery lifetime is extended. When the external battery voltage falls below the minimum value, or the external battery is removed, the unit automatically switches to internal battery power, so that the external battery can be changed without interrupting power supply to the phone, if the phone is on or during a call. An improved multi-phase software controlled battery-charging method and apparatus is used to charge the internal and external battery packs.

Abstract: In a secondary battery charging system and charging apparatus, when using either a step-down method or a constant-current/constant-voltage method of charging a secondary battery, a switching regulator is used to vary the charging current supplied to a secondary battery in accordance with the duty cycle of one pulse, so that a voltage that exceeds a pre-established voltage value is not applied to the secondary battery.

Abstract: A battery to be charged is preliminary charged with a first charge current. If a presumption can be made such that the battery has reached a fully charged condition before expiration of a first predetermined period of time during which the battery is charged with the first charge current, it is determined that either a fully charged battery or an inactive battery is subject to charging. Then, the battery is preliminary charged with a second charge current. If a fully charged presumption can be made before expiration of a second predetermined period of time during which the battery is charged with the second charge current, it is determined that the battery is already fully charged, whereas if such a presumption cannot be made during the second predetermined period of time, it is determined that the battery is the inactive battery.

Abstract: A battery charger (100) suitable for sub-miniaturization and connection to a wall transformer power supply (20) to charge a battery (30). The battery charger (100) features a switch (130) that controls flow of current from the transformer (20) either to output terminals for charging the battery (30) or to ground, a voltage regulator (120), a microprocessor (110), a current sensing resistor (150) and a Schottky diode (140). The microprocessor (110) is coupled to the switch (130) to control whether the switch is open or closed. The secondary leakage inductance of the wall transformer (20) is exploited to control charging of the battery. The microprocessor (110) is programmed to initiate a charging mode comprising oscillation between a conduction interval and a flyback interval. A charging pulse is delivered to the battery (30) during the flyback interval.

Abstract: The present invention provides a method of controlling rapid charging of an alkaline-electrolyte industrial storage cell of the "maintenance-free" or "sealed" type, the cell possessing a nominal capacity Cn, a voltage U, and an internal temperature T, wherein charging is stopped at a percentage charge greater than 75% of Cn as follows:a voltage threshold Us is fixed which corresponds to the desired final percentage charge for said cell;the voltage U and the temperature T of said cell are measured;a corrected voltage Uc is calculated using the following formula:Uc=U-k(T-Tc)where voltages are expressed in volts, Tc is an arbitrarily-selected reference temperature, and k is a constant coefficient expressed in volts per temperature unit; andUc is compared with said voltage threshold Us, and charging is stopped when Uc is not less than Us.

Abstract: In an exemplary fast charging system, a hand-held computerized terminal with rechargeable batteries therein may be bodily inserted into a charger receptacle. The terminal may have volatile memory and other components requiring load current during charging. The system may automatically identify battery type and progressively increase charging current while monitoring for an increase in battery terminal voltage to ascertain the level of load current. The battery temperature may be brought into a relationship to surrounding temperature such that by applying a suitable overcharge current value and observing any resultant temperature increase, the level of remaining battery charge can be determined. For example, if the battery is found to be relatively fully discharged, a relatively high fast-charge rate may be safely applied while monitoring battery temperature.

Abstract: For use with a reserve battery couplable to a charging circuit capable of providing a charging current to the reserve battery, a mode selection circuit and a method of operation thereof. The mode selection circuit includes, in one embodiment, (1) a signal generator that generates a signal based on a temperature of the reserve battery and (2) a mode-changing circuit, coupled to the signal generator, that accepts the signal and selects an alternative one of: (a) a non-charge mode in which the charging current is substantially interrupted when the temperature is greater than a reference temperature and (b) a charge mode in which the charging current is provided to the reserve battery when the temperature is less than the reference temperature.

Abstract: The present invention relates to a process for charging a battery from an alternating current voltage which provides voltage to the battery in each direction. The charging current is regulated alternatively in a boost and buck mode as a function of an error (AI) between the instant value of the current and an instant value of a supply current following a pre-determined pattern. The activation of the modes of operation is controlled according to the sign of the error of the current (AI). The present invention also relates to a battery charger for implementing the above charging process. The battery charger has two sub-assemblies for current regulation operating respectively in boost and buck modes, a subtractor for determining the error of current, and a common loop for feeding the sub-assemblies and controlling amplifiers for the activation, depending on the sign of the error.

Abstract: A fast charging method and apparatus for secondary cells, especially for lithium ion cells. The charging process has two charging phases. In the first charging phase, a constant current is supplied to the secondary cell from a charging apparatus whilst monitoring the output voltage of the charging apparatus. The first phase terminates when the output voltage of the charging apparatus reaches a predetermined maximum voltage (e.g., 4.2 volt for a lithium ion cell). Then, in the second charging phase, the output voltage of the charging apparatus being monitored and constant current pulses of fixed duration (e.g., 10 seconds) are supplied to the secondary cell in a manner such that the duration of intervals between such constant current pulses is controlled to maintain an average output voltage of the charging apparatus at a predetermined average voltage (e.g., 4.2 volt for a lithium ion cell). The charging is terminated when the duty cycle of the pulses falls below a predetermined value.

Abstract: A storage device allows the state of charge of a main battery to be determined by measuring the state of charge of a dummy battery. The storage device may provide power to an electronic appliance such as a portable computer. The main and dummy batteries each have a storage capacity and a self-discharge rate. The storage capacity of the dummy battery is less than the storage capacity of the main battery; for example, the storage capacity of the dummy battery may be only about 1% of that of the main battery. The main and dummy batteries are configured so that the self-discharge rates thereof are substantially equal. The storage device also includes discharge circuitry which is configured so that the dummy battery discharges at a rate faster than the main battery when a load is connected to and drawing current from the main battery.

Abstract: A rechargeable battery pack includes a rechargeable battery having a predetermined charge voltage, and a circuit for generating a control voltage depending on a battery voltage of the rechargeable battery so that the control voltage reaches a predetermined control voltage when the battery voltage reaches a predetermined charge voltage of the rechargeable battery. A battery charger for the rechargeable battery changes the charging control from constant-current to constant-voltage depending on whether the control voltage reaches the predetermined control voltage.

Abstract: A method of charging an industrial maintenance-free Ni-MH storage cell, the method comprising in combination a first stage at a constant current I.sub.1 lying in the range I.sub.c /10 to I.sub.c /2, and a second stage at a constant current I.sub.2 lying in the range I.sub.c /50 to I.sub.c /10, the changeover from the first stage to the second stage taking place when the time derivative of the temperature reaches a threshold value which varies as a function of the temperature at the time of the changeover.

Abstract: A power supply system for a portable device such as portable personal computer, to be operated from a DC power source supplied from a rechargeable battery or an AC adapter includes: an input current detecting circuit for detecting an input current supplied from the AC adapter and for generating a detection signal having a magnitude which varies depending upon the input current, and a charging current control circuit for controlling the amount of the charging current in response to the detection signal. The power supply system has low power losses and effects a high efficiency battery charging.

Abstract: A multi-rate charging circuit includes charging electronics adapted to condition power received from a power source according to operational settings for one or more charge parameters. A plurality of user-selectable charge sets each include settings for one or more of the charge parameters and one of the charge sets is designated as the current default charge set. The charging electronics assume the settings of the default charge set upon power-up, thereafter the user may select an alternative charge set if so desired. A trigger monitor, such as a current level sensor, monitors for the occurrence of a trigger event, such as low current flow associated with the removal of a battery pack, and generates a reset signal in response thereto. The reset signal causes the charging electronics to automatically assume the settings represented by the current default charge set for its operational settings.

Abstract: An electrochemical cell is recharged in series with a constant voltage source and a resistor, wherein the charging current declines as a function of increasing cell voltage. When the change in voltage of the battery with respect to time decreases to near zero, the changing cycle is ended or converted to a maintenance charge.

Abstract: A battery pack for an electronic device includes a housing separate from the electronic device wherein the housing can be mechanically connected to the electronic device. Electrical contacts on the housing provide electrical contact with the electronic device when connected thereto. A first battery interface in the housing receives a first battery, and a second battery interface in the housing receives a second battery. A switch in the housing connects either the first battery interface or the second battery interface to the electrical contacts in response to a selection by a user of the electronic device. Related systems and methods are also discussed.

Abstract: Apparatus to rapidly bulk charge a lead acid battery used in a "standby" power supply unit (PSU), or similar equipment containing said function, such as in an alarm panel system, fire panel (system) etc., without increasing the output capacity of the regulated PSU, significantly increasing its dissipation, size or cost, or causing an unacceptable recharge time of (often) several days. The apparatus comprises minimal additional components to provide a bulk charge of approximately 70% capacity to a 65 Ahr battery within 14 hours, while only drawing an average current of approximately 0.4 amp from the regulated PSU.

Abstract: The electronic circuit for supplying a voltage at a common output terminal (KI.U) has a number of supply circuits, each of which includes a source (B1, B2, . . . , Bn) of electric current and transistors (T10,T11; T20,T21; . . . ; Tn0,Tn1) connected with the source (B1, B2) to form an analog switch for gating the electric current, each supply circuit being connected with the common output terminal (KI.U); and a circuit device for controlling a potential at the gate electrodes of the transistors (T10,T11; T20,T21; . . . ; Tn0,Tn1) in each supply circuit, whereby the supply voltage (UV) is provided by a selected one of the supply circuits.

Abstract: The battery charging apparatus is provided with a charging power supply for electric power to charge rechargeable batteries, a first battery attachment section positioned close to the power supply, a second battery attachment section positioned further away from the power supply, and a charging controller which fully charges a rechargeable battery in the first battery attachment section faster than a rechargeable battery in the second battery attachment section.

Abstract: A dual mode battery charger includes an input that accepts a DC power signal, and a switch that switches the DC power signal from the input responsive to a control signal to generate a charging signal for the battery. A dual mode controller generates the control signal so that during a high current charging mode the switch is closed, and so that during a low current charging mode the switch is switched at a duty-cycle of less than 100 percent. In addition, a filter filters the charging signal to reduce a ripple portion thereof. Related methods and electronic devices are also discussed.

Abstract: An adaptive battery charger for charging batteries used in portable electronic devices. The battery charger monitors power provided from an AC adapter to the portable electronic device, and adaptively utilizes all available power from the AC adapter for charging the batteries, both when the portable electronic device is off, and when it is in use. As the power required for the portable electronic device increases, the power provided to the batteries decreases. As the power required to power the portable electronic device decreases, the power available to charge the batteries increases.

Abstract: The present invention is directed to a water purification and dispensing apparatus which receives power through induction to eliminate the presence of exposed electrical contacts terminals. The water dispenser includes a motor driven pump, a water storage area, a rechargeable battery and a nozzle, such that water is pumped from the water storage area out through the nozzle. Two electrodes are provided in either the water storage area or a separate tank for purifying water placed therein. When the dispenser and/or purifying tank is mounted on a base, inductors in the base, the dispenser, and the tank connect via mutual inductance such that power supplied by the base is received by the dispenser and tank. Since power transfers magnetically, there are no exposed contact points which could corrode and/or short if water is accidentally spilled thereon.

Abstract: A user-wearable docking system includes docking receptacles on a belt for receiving a plurality of electronic devices such as a hand-held personal data terminal, code reader, printer, etc. The plurality of electronic devices that are docked share power pursuant to one of several power management schemes. A power bus, disposed within a belt, connects all docks to supply power therebetween. Sharing battery power resources involves providing battery power for both device operation and for battery to battery recharging.

Abstract: In a charging system having a battery (104) with a high rate protection switch (120), and a charger (102) having a disable switch (221) that cooperates with a control switch transistor (224) to alternatively enable and disable the high rate protection switch, a method is employed by the charger to determine the presence or absence of the high rate protection circuit and apply an appropriate charge regime. The method includes applying a test current, then measuring the battery voltage while trying to disable the high rate protection circuit. If the voltage is sufficiently higher during such time, compared to normal operation, then the battery is charged at an ultrafast rate.

Abstract: There is disclosed a battery charging device for charging a battery pack having a battery cell, the battery pack being capable of storing an information for a maximum charging current and a maximum charging voltage of the battery cell and communicating the information with the battery charging device, which includes a communication means for receiving the information indicative of the maximum charging current and the information indicative of the maximum charging voltage of the battery cell which is transmitted from the battery pack, and a control means for controlling charging current and voltage upon charging so as not to exceed the maximum charging current and the maximum charging voltage of the battery cell. Further, in accordance with the present invention, there are disclosed a method for charging the battery pack, and the battery pack capable of being mounted to various electronic apparatuses.

Abstract: A method for charging a rechargeable battery pack includes providing a charger having first and second charging processes, and manually selecting one of the first and second charging processes. The charging method may include a step for indicating status or end of the selected one charging process. The first charging process may include the steps of providing a fast charging current, indicating end of the fast charging current and providing an equalization current. The second charging process may include the steps of providing a fast charging current, subsequently providing an equalization current and indicating end of equalization current. The second charging process may also include a temperature checking step. Further disclosed is a battery charging apparatus including a charger for charging a battery and having first and second charging processes, and a switch connected to the charger for manually selecting one of the first and second charging processes. The charger may include a microprocessor.

Abstract: A universal battery pack which contains an integral transformerless DC--DC switching power converter, with no DC connection between the battery and the power terminals. This provides inherent protection against overcurrent, and permits smaller fuse sizes to be used for a given current rating.

Abstract: A wireless communicator, such as a cellular telephone or personal communicator, includes a power source (e.g., two series connected batteries) providing output voltages VSS, VDD, and V1, where V1=(VDD-VSS)/2. The power source is coupled to a first load for powering the first load with VSS and VDD. The wireless communicator further includes a power source switching unit having first inputs coupled to VSS, VDD and V1, a second input coupled to a MODE signal, and outputs coupled to a second load. The power source switching unit is responsive to a first state of the MODE signal for powering the second load with VSS and V1, and is responsive to a second state of the MODE signal for powering the second load with V1 and VDD. By periodically toggling the MODE signal, such as at a frame rate of the wireless communicator, the power drawn from each battery by the second load is equalized, while providing the second load with a desired lower operating voltage.