BQ2085-V1P3 Datasheet, PDF (29/57 Pages) Texas Instruments – SBS-COMPLIANT GAS GAUGE IC FOR USE WITH THE bq29311

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bq2085-V1P3
SLUS598 − FEBRUARY 2004
sets MaxError( ) to 2% on completion of a learning cycle, unless the bq2085−V1P3 limits the learning cycle to
the +512/-256 mAh maximum adjustment values. If the learning cycle is limited, the bq2085−V1P3 sets
MaxError( ) to 8% unless MaxError( ) was already below 8%. In this case MaxError( ) does not change. The
bq2085−V1P3 increments MaxError( ) by 1% after four increments of CycleCount( ) without a learning cycle.
If voltage-based corrections are applied to the coulomb counter, MaxError( ) is set to 25%.
Purpose: The MaxError( ) function has real value in two ways: first, to give the user a confidence level about
the state of charge and second, to give the power management system information about how aggressive it
should be, particularly as the battery nears the end of its life.
SMBus protocol: Read word
Output: Unsigned integer—percent uncertainty for selected information.
Units: %
Range: 2–100%
Granularity: 1%
Accuracy: Not applicable
RelativeStateOfCharge( ) (0x0d)
Description: Returns the predicted remaining battery capacity expressed as a percentage of
FullChargeCapacity( ) (%).
Purpose: The RelativeStateOfCharge( ) function is used to estimate the amount of charge remaining in the
battery relative to the last learned capacity.
SMBus protocol: Read word
Output: Unsigned integer-percent of remaining capacity.
Units: %
Range: 0–100%
Granularity: 1%
Accuracy: -0, +MaxError( )
AbsoluteStateOfCharge( )(0x0e)
Description: Returns the predicted remaining battery capacity expressed as a percentage of
DesignCapacity( ) (%). Note that AbsoluteStateOfCharge( ) can return values greater than 100%.
Purpose: The AbsoluteStateOfCharge( ) function is used to estimate the amount of charge remaining in the
battery relative to the nominal or DesignCapacity( ).
SMBus protocol: Read word
Output: Unsigned integer—percent of remaining capacity.
Units: %
Range: 0–100+%
Granularity: 1%
Accuracy: -0, +MaxError( )
RemainingCapacity( ) (0x0f)
Description: Returns the predicted charge or energy remaining in the battery. The RemainingCapacity( ) value
is expressed in either charge or energy, depending on the setting of the BatteryMode( ) CAPACITY_MODE bit.
Purpose: The RemainingCapacity( ) function returns the battery’s remaining capacity. This information is a
numeric indication of remaining charge or energy given by the Absolute or Relative StateOfCharge( ) functions
and may be in a better form for use by power management systems.
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