Battery pack including static memory and a timer for charge management
First Claim
1. A removable battery pack for providing power to a computer system, the computer system including a microcontroller for detecting when said battery pack is connected to the computer system, means coupled to the microcontroller for determining the amount of charge provided to and provided by said battery pack while said battery pack is connected and computer system communication means coupled to the microcontroller for communicating with said battery pack, said battery pack comprising:
- a rechargeable battery;
a real time clock coupled to said battery for continually providing an indication of the present time; and
memory coupled to said battery for storing a timestamp value of said present time indication and a numerator value representing the remaining charge of said battery at approximately the time indicated by said timestamp value,wherein the microcontroller detects said battery pack when it is initially connected to the computer system, retrieves said present time indication and said timestamp and numerator values, and thereafter periodically updates said numerator based on the amount of charge provided to and provided by said battery and also updates said timestamp value with said present time indication while said battery pack is connected to said computer system.
3 Assignments
0 Petitions
Accused Products
Abstract
A battery pack for a computer system including static memory to maintain battery operating parameters and charge information, a real time clock (RTC) for measuring periods of non-use of the battery and a communication circuit to exchange the battery information with a microcontroller located in the computer system. The static memory, RTC and communication circuit is preferably in the form of a single RAM/RTC chip. The battery pack also includes circuitry to maintain power to the RAM/RTC from the battery if AC power is not available. The microcontroller detects the presence of the battery and retrieves the present time from the RTC, a timestamp indicating time or removal of the battery and other operating parameters and charge information from the battery pack, and controls the charging functions of the battery accordingly. The microcontroller also updates the charge information of the battery pack while performing other housekeeping functions of a DC--DC converter. The microcontroller further controls a switch located in the charge path of the battery to control fast charging. Trickle charge is simulated by pulsing the switch at a predetermined duty cycle and period. The microcontroller may be placed in standby to conserve energy, while also monitoring the standby switch to pull the computer system out of standby mode if the standby switch is pressed. This allows the keyboard controller to be shut off during standby mode to conserve energy.
-
Citations
34 Claims
-
1. A removable battery pack for providing power to a computer system, the computer system including a microcontroller for detecting when said battery pack is connected to the computer system, means coupled to the microcontroller for determining the amount of charge provided to and provided by said battery pack while said battery pack is connected and computer system communication means coupled to the microcontroller for communicating with said battery pack, said battery pack comprising:
-
a rechargeable battery; a real time clock coupled to said battery for continually providing an indication of the present time; and memory coupled to said battery for storing a timestamp value of said present time indication and a numerator value representing the remaining charge of said battery at approximately the time indicated by said timestamp value, wherein the microcontroller detects said battery pack when it is initially connected to the computer system, retrieves said present time indication and said timestamp and numerator values, and thereafter periodically updates said numerator based on the amount of charge provided to and provided by said battery and also updates said timestamp value with said present time indication while said battery pack is connected to said computer system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. A computer system, comprising:
-
a removable battery pack, comprising a rechargeable battery, a real time clock coupled to said battery for continually providing an indication of the present time, memory coupled to said battery for storing a timestamp of said present time indication and a numerator representing the remaining charge of said battery at approximately the time indicated by said timestamp, and battery pack communication means coupled to said battery, said real time clock and said memory for receiving, storing and transmitting said present time indication, said timestamp and said numerator; and a host computer for coupling to and receiving power from said battery pack, said host computer comprising; means for coupling to said battery pack for measuring the amount of charge provided to and provided by said battery, host computer communication means for coupling to said battery pack communication means for interfacing said host computer with said real time clock and said memory of said battery pack, means for detecting installation of said battery pack to said host computer, and processing means coupled to said host computer communication means, said detecting means and said measuring means, wherein said processing means retrieves said timestamp, said numerator and said present time indication after said detecting means detects installation of said battery pack, and thereafter, while said battery pack is connected to said host computer, said processing means periodically updates said numerator based on the amount of charge provided to and provided by said battery, and also periodically updates said timestamp with the current value of said present time indication. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
-
-
31. A method for determining the elapsed time during which a battery in a removable battery pack of a computer system is self-discharging, wherein the battery pack includes memory, comprising the steps of:
-
the battery pack continually providing a present time value; detecting whether the battery pack is installed on the computer system while the computer system is powered on; when the battery pack is first detected installed on the computer system, retrieving the present time value and a timestamp of the present time value previously stored in the memory of the battery pack; subtracting the retrieved stored timestamp from the present time value to calculate the elapsed time; and periodically reading a new timestamp of the present time value and storing the new timestamp in the battery pack memory while the battery pack is connected to the computer system and while the computer system is powered on.
-
-
32. A method for determining the amount of self-discharge of a battery in a removable battery pack of a computer system wherein the battery pack includes memory, comprising the steps of:
-
the battery pack continually providing a present time value; detecting whether the battery pack is installed on the computer system while the computer system is powered on; monitoring the amount of charge added to the battery during charging and the amount of charge removed during discharging of the battery while the battery pack is detected installed on the computer system; retrieving the present time value and a previously stored timestamp of the present time value from the battery pack memory when the battery pack is first detected installed on the computer system; subtracting the retrieved stored timestamp from the present time value to calculate an elapsed time of self-discharge; calculating the amount of self-discharge by multiplying the elapsed time by a predetermined self-discharge rate; and periodically reading a new timestamp of the present time value and storing the new timestamp into the battery pack memory while the battery pack is detected installed. - View Dependent Claims (33, 34)
-
Specification