
History
    98/07/24 First Release

Title    onHand/Ruputer Battery Life Detection

Table of Contents
1.Three conditions of battery
2.Two methods of detection
3.Flow chart of battery status
4.Detection timing

1.Three conditions of battery
     There are three conditions of onHand/Ruputer battery.
    (1)Normal ---   New battery.  There is no problem on both battery capacity and battery voltage.
                      The indicator in Filer shows the range between 100%~12.5%.
                    Even if the indicator shows more than 12.5%, if the voltage is low, BLD1,BLD2 condition may occur as explained in below.

    (2)BLD1 ---   This is the condition that a battery is almost running out so that the battery should be replaced. 
                     If a user do not operate any button/cursor pointer for 10 minutes then operate any button/cursor pointer, this message will displayed.  Beside this message, onHand/Ruputer operates normally. 
                    The indicator shows the range of 12.5%~0%.
                    Please note that if the voltage is low, BLD2 may be displayed.

    (3)BLD2 ---  Since there is high possibility that the circuit of onHand/Ruputer does not function normally, the circuit is terminated forcefully.  No button or cursor pointer is effective.  Only real-time clock (RTC) counts the time.
                    Only rest operation (press Filer, Enter, Menu button at the same time) can be done.  Replace a battery and reset onHand/Ruputer.
                    When a battery becomes 0% or the low voltage, move to BLD2.

2.Two methods of detection
    There are two methods of detection to detect three different levels of the battery condition.
    (1)Charge and discharge value
        When a battery is replaced, it is 100% and onHand/Ruputer calculates the consumed current.  Therefore, a new battery should be installed.  Otherwise, even if the indicator shows enough battery capacity, malfunction may occur.
        When the indicator shows 12.5%, the status moves from Normal to BLD1.
        When the indicator shows 0%, move to BLD2.
        The relationship between the % value of the indicator and the charge and discharge count value is as follows.

                    Battery Indicator   Charge and discharge count value
                    100%                160000000 (10 decimal)
                      0%                 32000000 (10 decimal)
        
        Please note that the relationship between the battery indicator and charge and discharge count value and the value of 12.5% that moves to BLD1 are the value in 98/07/24.  These values may be changed when a battery and circuit are improved.
         Please remember that the charge and discharge count value (Battery Indicator in Filer) is reset when a battery is replaced.  It is not initialized (100%) by pressing the Reset button.  The previous value is kept.

    (2)Battery Voltage Detection
         Calculate the battery voltage by measuring the load for a few seconds.
        There are following three detection voltage conditions regarding the battery life.
        
        * BLD1 voltage  ---      The status moves to BLD1 when the battery voltage becomes less than this voltage regardless of charge and discharge count value.
        * BLD2 voltage  ---      The status moves to BLD2 when the battery voltage becomes less than this voltage regardless of charge and discharge count value.
        * BLD1 revert voltage  ---  When the battery voltage is recovered by temperature and etc. after the status moved from BLD1 by BLD1 voltage detection and if the voltage is larger than BLD1 revert voltage, the condition is moved (reverted).
        
         Besides the above mentioned methods of voltage detection regarding the battery life, the following methods are prepared in order for onHand/Ruputer circuit to function normally. 
        
        * Detect the battery voltage when onHand/Ruputer is reset.
            When an old and low voltage battery is replaced and reset, malfunction of circuit and flash memory destruction may occur.  Therefore, the battery voltage should be checked in order to avoid these problems when onHand/Ruputer is reset.
        * Detect the battery voltage when EL and speaker start operating.
            When you operate EL and speakers (heavy load) under low temperature, the battery voltage decreases rapidly and malfunction may occur.  In order to avoid this problem, the detection of voltage is conducted during the operation.  If the low voltage is found, the heavy load is stopped forcefully.

RDFlow chart of battery status
    The flow of Normal, BLD1 and BLD2 is as follows.
    (1)Status movement by detecting the capacity (charge and discharge count)
                   BLD1 capacity              BLD2 capacity
        +--------+  detection      +--------+  detection        +--------+ 
        | Normal | --------------> |  BLD1  | ----------------> |  BLD2  |
        |        |                 |        |                   |        |
        +--------+                 +--------+                   +--------+ 
        * If the status moves to [BLD1] by capacity detection, it is not reverted to [Normal].
        * If the status moves to [BLD2], the circuit is terminated forcefully.
        * If the status moves to [BLD2], it is not reverted to [Normal] or [BLD1].
    
    (2)Status movement by detecting voltage
                   BLD1 voltage               BLD2 voltage
        +--------+  detection      +--------+  detection        +--------+ 
        | Normal | --------------> |  BLD1  | ----------------> |  BLD2  |
        |        | <-------------- |        |                   |        |
        +--------+  BLD1 reverted  +--------+                   +--------+ 
                  voltage detection
        * If the status moves to [BLD1] by the voltage detection, it is reverted to [Normal] by the BLD1 reverted voltage.
        * If the status moves to [BLD2], the circuit is terminated forcefully.
        * If the status moves to [BLD2], it is not reverted to [Normal] or [BLD1].

4.Detection Timing
    The detection timing of "charge and discharge count value" regarding the battery condition movement and the detection timing of "battery voltage" are as follows.
    (1) Charge and discharge count value
    * Charge and discharge count value is checked every one hour.
    (2) Battery voltage estimation value
    * The battery voltage is checked very two hours.

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 Copyright (c) 1998-1999.  Seiko Instruments Inc.  All rights reserved. 
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