Smart battery selector offering power conversion internally within a portable device

• US 5,903,764 A
• Filed: 05/02/1997
• Issued: 05/11/1999
• Est. Priority Date: 05/02/1997
• Status: Expired due to Term

• Current Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Original Assignee: O2 Micro Incorporated
• Inventors: Shyr, You-Yuh, Du, Sterling, Liu, Kwang H.
• Primary Examiner(s): Sheikh, Ayaz R.
• Assistant Examiner(s): JEAN, FRANTZ B
• Application Number:
  US08/850,335
• Time in Patent Office: 739 Days
• Field of Search: 320/48, 320/15, 320/6, 320/106, 320/162, 320/164, 320/124, 320/128, 320/134, 320/DIG. 21, 307/64, 395/750.01
• US Class Current: 713/300
• CPC Class Codes: G01R 31/36 Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0024 Parallel/serial switching of connection of batteries to charge or load circuit

Abstract

A controller for a smart battery selector included in a portable device has a plurality of switch-drivers at least equal to a plurality of smart batteries. The batteries provide battery-state data via a bus to a host computer included in the portable device. Each switch-driver effects selection of an associated battery. A control electronic-circuit in the controller directs operation of the switch-drivers for selecting the battery so that at any instant only one battery powers the portable device. A bus-snooper circuit permits the controller to independently monitor the bus for battery-condition alarm-messages. The controller may respond to such messages by selecting a different battery. The controller may also select a single battery for recharging, and may terminate charging upon receiving a battery overcharge message.

Claims

1. A controller for a battery selector that is adapted for use with at least two smart batteries, said smart batteries being capable of providing electrical power for energizing operation of a portable device and also providing battery-state data via a bus to a host computer included in the portable device, the battery-state data provided by the smart batteries including a battery-condition alarm-message which indicates that the smart battery that transmits the battery-condition alarm-message has experienced a pre-specified conditions the controller comprising:

smart-battery-selection switch-drivers at least equal in number to the smart batteries included in the portable device, each smart-battery-selection switch-driver being associated with a specific smart battery and providing a battery selection-signal for effecting a selection of the associated smart battery which causes the selected smart battery to energize operation of the portable device;

an internal-power-converter switch-driver associated with at least one of the smart batteries to select, for supplying electrical power to energize operation of the portable device, an external electrical power-source that is coupled to the portable device by an internal electrical-power converter which physically replaces one of the smart batteries;

a control electronic-circuit that controls operation of the smart-battery-selection switch-drivers and the internal-power-converter switch-driver for selecting to energize operation of the portable device at any instant either;

a. the smart battery associated with a particular smart-battery-selection switch-driver;

or

b. the external electrical power-source that is coupled to the portable device by the internal electrical-power converter;

an internal-voltage-conversion sensing-circuit for sensing voltage provided by the external electrical power-source that is coupled to the portable device by the internal electrical-power converter, if the voltage sensed by said internal-voltage-conversion sensing-circuit exceeds a pre-established threshold, the controller transmitting a signal to said control electronic-circuit directing said control electronic-circuit to select the external electrical power-source that is coupled to the portable device by the internal electrical-power converter to energize operation of the portable device; and

a bus-snooper circuit that independently of the host computer monitors the bus for the battery-condition alarm-message from the smart batteries, and that upon detecting the battery-condition alarm-message transmits a signal to said control electronic-circuit.

2. The controller of claim 1

wherein the smart-battery-selection switch-drivers, operating under control of said control electronic-circuit, provide battery selection-signals to select one of the smart batteries to energize operation of the portable device so that at any instant only one of said smart-battery-selection switch-drivers effects a selection of the associated smart battery to energize operation of the portable device;

wherein the battery-condition alarm-message detected by the bus-snooper circuit is a low-battery-capacity message; and

wherein the signal transmitted by said bus-snooper circuit causes said control electronic-circuit to attempt selection of a different smart battery to energize operation of the portable device.

3. The controller of claim 1 further comprising a battery-voltage sensing-circuit for sensing smart-battery voltage independently from the smart batteries, the controller using the voltage thus sensed in attempting to select a different smart battery to energize operation of the portable device.

4. The controller of claim 1 wherein the controller further include an external power-converter switch-driver for effecting a selection of an electrical power-source that is external to the portable device to energize operation of the portable device, said control electronic-circuit also controlling operation of said external power-converter switch-driver for effecting a selection of the external electrical power-source so that at any instant an ensemble of said smart-battery-selection switch-drivers and said external power-converter switch-driver selects either one of the smart batteries or the electrical power-source to energize operation of the portable device, and:

wherein the controller further comprises an external-voltage sensing-circuit for sensing voltage provided by the external electrical power-source; and

if the voltage sensed by said external-voltage sensing-circuit exceeds a pre-established threshold, said external-voltage sensing-circuit transmitting a signal to said control electronic-circuit directing said control electronic-circuit to select the external electrical power-source to energize operation of the portable device.

5. The controller of claim 1

wherein said smart-battery-selection switch-drivers, operating under control of said control electronic-circuit, select one of the smart batteries included in the portable device for recharging so that at any instant only one smart battery is being recharged;

wherein the battery-condition alarm-message detected by the bus-snooper circuit is an overcharge battery-condition message; and

wherein the signal transmitted by said bus-snooper circuit causes said control electronic-circuit to attempt selection of a different smart battery for recharging.

6. The controller of claim 5 further comprising a battery-charging-rate circuit which receives a battery charging-rate signal that indicates if a smart battery is being charged at a fast or a slow rate, the controller permitting a power-management computer program executed by the host computer to retrieve data indicative of such battery charging-rate signal from the controller.

7. The controller of claim 1 wherein the controller stores operating-mode data that in a first state activates response of the controller to operation of said bus-snooper circuit, and in a second state deactivates response of the controller to operation of said bus-snooper circuit.

8. The controller of claim 1

wherein smart-battery-selection switch-drivers, operating under control of said control electronic-circuit, provide battery selection-signals to select one of the smart batteries to energize operation of the portable device so that at any instant only one of said smart-battery-selection switch-drivers effects a selection of the associated smart battery to energize operation of the portable device;

wherein the controller further includes a timer for establishing a pre-established time interval; and

wherein, if said bus-snooper circuit fails to receive a battery-condition alarm-message throughout the pre-established time interval established by said timer, said control electronic-circuit causes said control electronic-circuit to attempt selection of a different smart battery.

9. A battery powered portable device comprising:

a host computer;

at least two smart batteries, said smart batteries being capable of providing electrical power for energizing operation of the portable device;

a bus to which said smart batteries may be coupled and over which said smart batteries may transmit battery-state data to said host computer, the battery-state data provided by said smart batteries including a battery-condition alarm-message which indicates that said smart battery that transmits the battery-condition alarm-message has experienced a pre-specified condition; and

a battery selector that is coupled to said smart batteries, said battery selector including a controller that has;

smart-battery-selection switch-drivers at least equal in number to the smart batteries included in the portable device, each smart-battery-selection switch-driver being associated with a specific smart battery and providing a battery selection-signal for effecting a selection of the associated smart battery which causes the selected smart battery to energize operation of the portable device;

an internal-power-converter switch-driver associated with at least one of the smart batteries to select, for supplying electrical power to energize operation of the portable device, an external electrical power-source that is coupled to the portable device by an internal electrical-power converter which physically replaces one of the smart batteries;

a control electronic-circuit that controls operation of the smart-battery-selection switch-drivers and the internal-power-converter switch-driver for selecting to energize operation of the portable device at any instant either;

a. said smart battery associated with a particular smart-battery-selection switch-driver;

or

b. the external electrical power-source that is coupled to the portable device by the internal electrical-power converter;

an internal-voltage-conversion sensing-circuit for sensing voltage provided by the external electrical power-source that is coupled to the portable device by the internal electrical-power converter, if the voltage sensed by said internal-voltage-conversion sensing-circuit exceeds a pre-established threshold, the controller transmitting a signal to said control electronic-circuit directing said control electronic-circuit to select the external electrical power-source that is coupled to the portable device by the internal electrical-power converter to energize operation of the portable device; and

a bus-snooper circuit that independently of said host computer monitors said bus for the battery-condition alarm-message from said smart batteries, and that upon detecting the battery-condition alarm-message transmits a signal to said control electronic-circuit.

10. The battery powered portable device of claim 9

wherein smart-battery-selection switch-drivers of the controller included in said battery selector, operating under control of said control electronic-circuit, select one of said smart batteries to energize operation of the portable device so that at any instant only one of said smart-battery-selection switch-drivers effects a selection of the associated smart battery to energize operation of the portable device;

wherein the battery-condition alarm-message detected by the bus-snooper circuit is a low-battery-capacity message; and

wherein the signal transmitted by said bus-snooper circuit causes said control electronic-circuit to attempt selection of a different smart battery to energize operation of the portable device.

11. The battery powered portable device of claim 9, wherein the controller included in said battery selector includes a battery-voltage sensing-circuit for sensing smart-battery voltage independently from the smart batteries, the controller using the voltage thus sensed in attempting to select a different smart battery to energize operation of the portable device.

12. The battery powered portable device of claim 9 being adapted to be energized by an electrical power-source supplied externally to the portable device;

and

wherein, in addition to said smart-battery-selection switch-drivers associated with said smart batteries included in the portable device, switch-drivers of the controller further include an external power-converter switch-driver for effecting a selection of an electrical power-source that is external to the portable device to energize operation of the portable device, said control electronic-circuit also controlling operation of said external power-converter switch-driver for effecting a selection of the external electrical power-source so that at any instant an ensemble of said smart-battery-selection switch-drivers and said external power-converter switch-driver selects either one of the smart batteries or the electrical power-source to energize operation of the portable device, and;

wherein the controller further comprises an external-voltage sensing-circuit for sensing voltage provided by the external electrical power-source; and

if the voltage sensed by said external-voltage sensing-circuit exceeds a pre-established threshold, said external-voltage sensing-circuit transmitting a signal to said control electronic-circuit directing said control electronic-circuit to select the external electrical power-source to energize operation of the portable device.

13. The battery powered portable device of claim 9

wherein smart-battery-selection switch-drivers of the controller included in said battery selector, operating under control of said control electronic-circuit, select one of the smart batteries included in the portable device for recharging so that at any instant only one smart battery is being recharged;

wherein the battery-condition alarm-message detected by the bus-snooper circuit is an overcharge battery-condition message; and

wherein the signal transmitted by said bus-snooper circuit causes said control electronic-circuit to attempt selection of a different smart battery for recharging.

14. The battery powered portable device of claim 13 wherein the controller included in said battery selector includes a battery-charging-rate circuit which receives a battery charging-rate signal that indicates if a smart battery is being charged at a fast or a slow rate, the controller permitting a power-management computer program executed by said host computer to retrieve data indicative of such battery charging-rate signal from the controller.

15. The battery powered portable device of claim 9 wherein the controller included in said battery selector stores operating-mode data that in a first state activates response of the controller to operation of said bus-snooper circuit, and in a second state deactivates response of the controller to operation of said bus-snooper circuit;

wherein said host computer of the portable device may operate in a Suspend mode in which the portable device including said host computer consumes a lesser amount of electrical power because certain portions of said portable device including said host computer are turned-off; and

wherein the controller stores first state operating-mode data transmitted from said host computer to the controller before said host computer enters the Suspend mode whereby the operating-mode data stored in the controller activates response of the controller to operation of said bus-snooper circuit while said host computer is in the Suspend mode.

16. The battery powered portable device of claim 9

wherein smart-battery-selection switch-drivers of the controller included in said battery selector, operating under control of said control electronic-circuit, select one of said smart batteries to energize operation of the portable device so that at any instant only one of said smart-battery-selection switch-drivers effects a selection of the associated smart battery to energize operation of the portable device;

wherein the controller included in said battery selector further includes a timer for establishing a pre-established time interval; and

wherein, if said bus-snooper circuit fails to receive a battery-condition alarm-message throughout the pre-established time interval established by said timer, said control electronic-circuit causes said control electronic-circuit to attempt selection of a different smart battery.