Advanced intelligent computer power management system

• US 6,181,103 B1
• Filed: 07/29/1999
• Issued: 01/30/2001
• Est. Priority Date: 05/27/1997
• Status: Expired due to Fees

• Current Assignee: Shu-Chin Chen
• Original Assignee: Shu-Chin Chen
• Inventors: Chen, Shu-Chin
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/363,395
• Time in Patent Office: 551 Days
• Field of Search: 320/112, 320/106, 320/113, 320/137, 702/63
• US Class Current: 320/106
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/448 End of discharge regulating measures
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 10/488 Cells or batteries combined with indicating means for external visualization of the condition, e.g. by change of colour or of light density
• CPC Class Codes: H01M 2200/105 NTC
• 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 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

This invention is for the advanced intelligent computer power management (AICPM) system. The main features of this invention include converting the traditional smart battery pack into a removable and data accessible (RADA) battery pack and an intelligent power management algorithm embedded in the host computer. The improved RADA battery pack contains a temperature sensor, a display unit, and a memory (EEPROM). Peripherals mounted on the host computer side which contains a control unit, a charging circuit, a load circuit, a voltage divider, a current detector, a temperature control circuit, and a data bus are used to cope with the removal and data access operation for the AICPM system. The removable and data-accessible battery pack utilizes the functions provided by this invention to read, update, and record data about the battery pack, such as number of times used, remaining capacity, usable time, and nominal capacity. It also stores these data in the EEPROM of the RADA battery pack so that when the battery pack is used next time, the AICPM system can read out these data from the EEPROM and use them as the battery pack new information.

Claims

1. An advanced intelligent computer power management (AICPM) system, comprising:

a removable data accessible (RADA) battery pack, including;

a battery pack having several rechargeable battery cells,

a display that shows a power capacity status of said RADA battery pack,

a memory, including an electrical erasable programmable read only memory (EEPROM), that stores data, and

a temperature sensor having a thermister with a negative temperature coefficient; and

an AICPM system that plans and manages said RADA battery pack, including;

a microprocessor unit (MPU) having a single chip microcomputer that executes the software program used for battery management,

voltage dividing resistors having serial precision resistors that sense the terminal voltage of the RADA battery pack,

a current sensor having a precision resistor, a voltage level converter and a voltage frequency converter that sense the charging/discharging current of the battery pack,

a voltage detector having a voltage regulating amplifier that detects the terminal voltage of said RADA battery pack,

a temperature sensor having a linear amplifier that detects the surface temperature of said RADA battery pack,

a voltage stabilizing rectifier having a voltage stabilizing transistor circuit that provides the hardware unit with a stable operating power source,

a loop current sense resistor having a precision resistor with a small value that detects a direction and amplitude of charging/discharging current of said RADA battery pack, and

a charging circuit that provides said RADA battery pack with a charging voltage source;

wherein said MPU directly outputs a signal to control the switch on or off of the charging or discharging current; and

wherein said MPU automatically performs power management according to the signal variations obtained from the peripheral parts.

2. An AICPM system according to claim 1, wherein said memory in said RADA battery pack includes an EEPROM, wherein said EEPROM stores real time information including basic characteristic data of said RADA battery pack, remaining power capacity, amount of time used, the time of data storage recorded for the last one data, and wherein the real time information is provided to said MPU of said AICPM system as a reference to evaluate the performance of said RADA battery pack.

3. An AICPM system according to claim 1,

wherein said temperature sensor of said RADA battery pack senses the temperature of said RADA battery pack,

wherein an environment temperature is provided to said RADA battery pack under operation for the evaluation of a terminal voltage, said MPU of said AICPM System evaluates a variation of the end voltage of said RADA battery pack due to temperature, and the evaluated result is used as an investigation reference for dynamic adjustment of the end of discharge voltage, and

wherein further information for the investigation of the saturation characteristic of said RADA battery pack in the charging state is determined.

4. An AICPM system according to claim 1, further comprising a data bus that enables communication between said RADA battery pack and said AICPM system.

5. An AICPM system according to claim 4, wherein said RADA battery pack and said AICPM system are connected to an exclusively external plug-draw connector.

6. An AICPM system according to claim 4, wherein said plug-draw connector includes a data bus, an EEPROM, a power supply input terminal, a temperature sensor, a display control and LEDs.

7. An AICPM system according to claim 1, further comprising a resistor that provides a serial connection between a charging/discharging load and said RADA battery pack to form a current loop,

wherein a low level voltage drop is obtained by the rule of V=IR,

wherein further the voltage level is transformed to a practical voltage level by a voltage level shifter, and is converted to a related frequency value by a voltage-frequency converter, and

wherein further said counter of said MPU further converts the converted frequency value proportionally to an equivalent loop current value.

8. An AICPM system according to claim 7, wherein said voltage level shifter is used to linearly adjust the different polarity of charge/discharge voltage to a voltage value of 0˜

V/2 (discharge) and V/2˜

V (charge), which are voltage values matched to a linear operation region of a single power supplied operational amplifier, using the stable voltage drop of the diode, wherein the stable reference bias is obtained for the converting circuit.

9. An AICPM system according to claim 7, wherein said voltage to frequency converter also includes a stable current source that linearly converts the small output voltage variation of voltage level shifter to the frequency variation at n/n Hz per n mV.

10. An AICPM system according to claim 1,

wherein said voltage detector is utilized by a rule of voltage dividing which is {V=R₁/((R₁+R₂))V_b},

wherein the output voltage varies between 0-5 V, the voltage is converted to a proportional digital signal by an A/D converter in said MPU, the digital signal is provided to the voltage algorithm in said MPU for recording and evaluating the variation of terminal voltage of the RADA battery pack, and said MPU examines the charging/discharging performance of said RADA battery pack.

11. An AICPM system according to claim 1, wherein said temperature sensor uses said thermal sensitive resistor in said RADA battery back to sense a variation of temperature,

wherein the characteristic of the voltage variation (V=IR) produced by the temperature variation is obtained and amplified by an amplifier, the amplified voltage is proportionally converted to a digital signal by an A/D converter in said MPU, the digital signal is provided to the temperature algorithm in said MPU for recording and evaluating the temperature variation of said RADA battery, and said MPU can examine the performance of said RADA battery pack during charging/discharging process.

12. An AICPM system according to claim 11, wherein the nonlinear characteristic of the thermal sensitive resistor (R_h) is converted to a linear characteristic resistor by said divider resistor (R₁) and a reasonable resistance adjustment, wherein said R₁ is connected with said R_h serially to obtain the voltage dividing effect {V_T=[R_h/(R₁+R_h)]V_b}.

13. An AICPM system according to claim 1, wherein:

in a charging mode, said MPU controls the charging voltage and current for said battery pack and monitors a battery terminal voltage, calculates related parameters and stores the calculated parameters in said EEPROM, and if the capacity of said battery pack is not saturated, the charging parameters are calculated continually, and if the capacity of said battery pack saturated, a warning signal of saturation is indicated and said charger is turned off, and

in a discharging mode, said MPU monitors said battery terminal voltage, charging network current, and temperature variation, calculates discharging parameters, stores the discharging parameters in said memory, and determines an END of discharge voltage (EDV) of said battery pack, and if the EDV does not reach a discharging cut off voltage the discharge parameters are calculated continually, and if the EDV does reach the lower limit of the discharging voltage a low capacity warning signal is indicated and the charging circuit is turned on.

14. An AICPM system according to claim 13, wherein said MPU controls said charging circuit in the charging mode, and

wherein, in an operating mode:

if a temperature of said battery is higher than 0 degrees (Fahrenheit (F.)) or lower than 65 degrees (F.), said battery pack is determined to be in the normal charging mode, and the charging behavior for said battery is either in a limited constant voltage/current source or a limited constant current/voltage source, according to a preset charging value,

if the battery temperature increases more than n degrees (F.) per minute or the temperature is higher than 65 degrees (F.) or the current of the battery circuit decreases or the terminal voltage of the battery is in a mode of Δ

V, then the battery is determined to be saturated, and

if the battery temperature is lower than 0 degrees (F.), said MPU controls the charging circuit to charge said battery in a pulse charging mode until the temperature of batter is higher than 0 degrees (F.) at which the charging mode converts to the normal charging mode.

15. An AICPM system according to claim 13,

wherein said MPU records a discharging current, the terminal voltage, and temperature of the battery during discharging mode, and wherein said MPU calculates an estimated time to reach a lowest power capacity as well as parameters related thereto, and

wherein, when the power capacity reaches the preset value of end of discharge voltage (EDV), said MPU generates a request to the keyboard controller through the data bus to instruct the user to turn off the computer.

16. An AICPM system according to claim 1, wherein the built-in power management/control software in said MPU performs:

dynamically correcting the end of discharge voltage (EDV) by investigating the battery temperature, cycle count, and the battery saturation voltage;

determining the practical mode of use for said battery based on the completely charging/discharging behavior of said battery or based on behavior of said battery in an estimated compensation mode in which said battery is not completely charged/discharged;

calculating the status of a practical upper limit of full capacity of said batter by precisely estimating the parameter of cycle count and the dynamic terminal voltage correction value of said battery pack; and

estimating the status of battery operation by precisely compensating the hardware and using a software correction technique.

17. An AICPM system according to claim 16, wherein said dynamically correcting the end of discharge voltage (EDV)includes:

correcting the value of the EDV by relating a temperature variation and battery terminal voltage variation, and the estimated time to turn off the computer does not change; and

investigating the life of said battery by precisely counting the cycle count of said battery and then correcting the value of the EDV based on aging characteristics of said battery, and the estimated time to the end of battery maintains a constant value and the estimated time to turn off the computer is obtained.

18. An AICPM system according to claim 16, wherein said determining the practical mode of use for said battery is performed in an accumulation estimation mode, wherein a cycle count of the charging/discharging is incremented to correct the accumulation error of cycle count caused by the incompletely charging/discharging process.

19. An AICPM system according to claim 1, wherein said MPU determines the behavior mode of the management/control software by investigating the connection status between said temperature sensor in the RADA Battery Pack, the temperature sensor in the AICPM System, and the contents of said EEPROM.