Abstract:
When charging a battery in an electronic device, if a charging current or voltage is too high, the electronic device sends a command to stop the charging. However, if an error occurs in the charge circuit, leading to continuous charging of the battery instead of stopping the charging, then the electronic device enters a power consumption mode to consume electric power charged to the battery in the electronic device. This reduces damage due to overcharging the battery.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is related to a method for managing electric power of a battery, more particularly, to a method for consuming electric power charged to a battery in an electronic device when the battery cannot be electrically decoupled from an external power supply. 
         [0003]    2. Description of the Prior Art 
         [0004]    Most portable electronic devices, such as mobile phones, use a rechargeable battery as a power source. These electronic devices are capable of connecting to an adapter to charge the battery of the electronic device. For charging safety, protective circuits are installed in the electronic device to cut off a charging current to prevent the battery from exploding when a charging error occurs. 
         [0005]    When the charging circuit of the mobile phone does not operate correctly, and therefore cannot successfully cut off the charging current, the mobile phone will send alarm signals to alert a user. However, the alarm signals are not activate indefinitely. For example, the mobile phone may cause a backlight of a display panel of the mobile phone to flash in order to alert the user. However, some mobile phones stop after the display panel has flashed several times. When the display panel flashes, the user may be too far away to notice. On the other hand, the user may check the mobile phone after the display panel has stopped flashing, such that the user continues charging the battery of the mobile phone. Under these circumstances, the battery has a high probability of exploding. 
       SUMMARY OF THE INVENTION 
       [0006]    The claimed invention provides a method for consuming electric power charged to a battery in an electronic device when the battery cannot be electrically disconnected from a power supply, the method comprising sending a command to disconnect the battery and the power supply when the power supply charges the battery to a predetermined status; detecting whether the battery is still electrically connected to the power supply after sending the command to disconnect the battery and the power supply; and entering a power consumption mode to consume electric power charged to the battery if detecting that the battery is still electrically connected to the power supply. 
         [0007]    The claimed invention provides an electronic device comprising a battery for providing electric power to the electronic device; a first detecting device for detecting a predetermined status of a power supply charging the battery; a second detecting device for detecting whether the battery is still electrically coupled to the power supply after sending a command to decouple the battery from the power supply; a power management unit for managing electric power; and a baseband control unit coupled to the power management unit for controlling the power management unit to provide electric power to the electronic device. 
         [0008]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a block diagram of a mobile phone according to the present invention. 
           [0010]      FIG. 2  is a flow chart of controlling a charging status of the mobile phone in  FIG. 1  according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    To solve the problem in the prior art that an error that occurs during battery charging may cause damage, power consuming elements are started to consume electric power that is charging a battery of a mobile phone according to the present invention. 
         [0012]    Please refer to  FIG. 1 .  FIG. 1  is a block diagram of a mobile phone  10  according to the present invention. The mobile phone  10  includes a battery  20 , a first detecting device  18 , a second detecting device  16 , a power management unit  12 , and a baseband control unit  14 . The battery  20  provides electrical power to the mobile phone  10 . The power management unit  12  manages the electrical power. The baseband control unit  14  is coupled to the power management unit  12  and controls the power management unit  12  to provide the electrical power to internal elements of the mobile phone  10 , such as a vibrator  31 . 
         [0013]    Potential dangers during battery charging include high charging voltage, high charging current, and high temperature of the battery, so it is necessary to detect whether a charging status of the battery is within a safe range. When the external power supply  22  charges the battery  20  of the mobile phone  10 , the first detecting device  18  detects the charging status of the battery  20 . 
         [0014]    For example, a charging time of the battery  20  will be detected if it reaches a predetermined time. If the battery  20  has internal damage so that cannot be charged to full, the external power supply  22  will continue charging the battery  20 . However, the battery  20  cannot store more electric energy. The excessive electric energy may damage the battery  20  or the mobile phone  10 . Detecting the charging time can prevent potential danger of charging for too long. 
         [0015]    Furthermore, the charging current and voltage can be detected by measuring a voltage across a resistor R. When the charging current and voltage are too large, i.e. outside of the safe range, danger of the battery  20  exploding increases. In general, at different charging stages, an acceptable charging current of the rechargeable battery is around 30 to 500 mA, and the external power supply  22  inputs current around 700 mA. The circuit electrically coupled between the external power supply  22  and the battery  20  can regulate the input current to be within the safe range. 
         [0016]    The battery  20  has a thermodetector and an IC which can detect the characteristic of the battery  20 , so the first detecting device  18  can determine whether the voltage of the battery  20  approaches the maximal storage or the temperature of the battery  20  approaches a predetermined temperature to prevent the battery  20  from the damage from high temperature or high voltage. 
         [0017]    When the first detecting device  18  detects an error in the charging status, the baseband control unit  14  sends a command to decouple the battery  20  from the external power supply  22 . After sending the command to decouple, the second detecting device  16  detects whether the battery  20  is still coupled to the external power supply  22 . Similarly, the second detecting device  16  detects a current flowing in the resistor R by measuring the voltage of the resistor R. If the current of the resistor R is zero, or lower than the acceptable range, such as 5 mA, this means that the battery  20  and the external power supply  22  have definitely decoupled. If the second detecting device  16  detects a current larger than the acceptable range, then the external power  22  is still charging the battery  20 . Because the circuit for electrically connection cannot work normally, the input current 700 mA may charge the battery  22  directly, damaging the battery  20  or causing the batter  20  to explode. Therefore, the baseband control unit  14  starts the power consumption mode to consume the large input current. 
         [0018]    The baseband control unit  14  can start the vibrator  31  as shown in  FIG. 1 , which can consume approximately 100 mA of current. The baseband control unit  14  can also start other elements in the mobile phone  10 . The audio amplifier, such as a speaker, a buzzer, or a headset, can consume approximately 200 mA of current. The liquid crystal display backlight module  33  can consume approximately 20 mA of current. The keypad LED  34  can consume approximately 40 mA of current. The organic light-emitting diode (OLED)  35  can consume approximately 20 mA of current. The liquid crystal display (LCD)  36  can consume approximately 40 mA of current. The bluetooth module  37  or the digital still camera (DSC)  38  can consume approximately 50 mA of current. The power amplifier  39  can consume approximately 100 to 1000 mA of current. 
         [0019]    When the mobile phone  10  is in a power-saving mode, the baseband control unit  14  can turn off the power saving mode to consume a current of around 50 to 120 mA. Therefore, when the external or internal charging elements of the mobile phone  10  cannot work normally to cut off the charging current, the mobile phone  10  according to the present invention can start the power consuming elements to reduce the danger of the overcharging. 
         [0020]    Please refer to  FIG. 2 .  FIG. 2  is a flow chart of controlling the charging status of the mobile phone  10  in  FIG. 1  according to the present invention. Steps of the method according to the present invention are as follows: 
         [0021]    Step  201 : the first detecting device  18  detects whether the charging status is regular; if yes, go to step  203 ; if no, go to step  202 ; 
         [0022]    Step  202 : the baseband control unit  14  sends a command to decouple the battery  20  from the external power supply  22 ; the second detecting device  16  detects whether the battery  20  is decoupled from the external power supply  22 ; if yes, go to Step  204 ; if no, go to step  205 ; 
         [0023]    Step  203 : continue to charge the battery  20 ; go to step  201 ; 
         [0024]    Step  204 : charging ends; 
         [0025]    Step  205 : the baseband control unit  14  starts the power consumption elements of the mobile phone  10 . 
         [0026]    The method and the device according to the present invention can have applications to the mobile phone  10  and other electronic devices, such as digital still cameras, personal digital assistants, or digital video cameras. In addition, when the mobile phone  10  according to the present invention detects the battery  20  cannot be disconnected from charging normally, the mobile phone  10  will send alarm signals to notify users, e.g. beeping from the buzzer or flashing the light of the panel. 
         [0027]    In contrast with the prior art, the present invention provides a proper handling method that can effectively reduce the probability of the battery exploding resulting in damage and danger. 
         [0028]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.