BQ2085 Datasheet, PDF (34/56 Pages) Texas Instruments – SBS-COMPLIANT GAS GAUGE IC FOR USE WITH THE bq29311

bq2085
SLUS541 – OCTOBER 2002
REMAINING_TIME_ALARM bit is set when the bq2085 detects that the estimated remaining time at the present
discharge rate is less than that set by the RemainingTimeAlarm( ) function. This bit is cleared when either the
value set by the RemainingTimeAlarm( ) function is lower than the AverageTimeToEmpty( ) or when the
AverageTimeToEmpty( ) is increased by charging.
Status Bits
The initialized bit is set when the bq2085 is has detected a valid load of data flash at full or partial reset. It is
cleared when the bq2085 detects an improper data flash load.
DISCHARGING bit is set when the bq2085 determines that the battery is not being charged. This bit is cleared
when the bq2085 detects that the battery is being charged.
FULLY_CHARGED bit is set when the bq2085 detects a primary charge termination or an Overcharge
condition. It is cleared when RelativeStateOfCharge( ) is less than the programmed Fully Charged Clear % in
DF 0x47.
FULLY_DISCHARGED bit is set when Voltage( ) or VCELL is less than the EDV2 threshold and Current( ) <
Overload Current or when RelativeStateOfCharge( ) < Battery Low %. This bit is cleared when
RelativeStateOfCharge( ) is greater than or equal to 20%.
Error Codes
ERROR CODES
OK
Busy
Reserved
Unsupported
AccessDenied
Over/Underflow
BadSize
UnknownError
DESCRIPTION
The bq2085 processed the function code without detecting any errors.
The bq2085 is unable to process the function code at this time.
The bq2085 detected an attempt to read or write to a function code reserved by this version of the specification.
The bq2085 detected an attempt to access an unsupported optional manufacturer function code.
The bq2085 does not support this function code which is defined in this version of the specification.
The bq2085 detected an attempt to write to a read-only function code.
The bq2085 detected a data overflow or underflow.
The bq2085 detected an attempt to write to a function code with an incorrect data block.
The bq2085 detected an unidentifiable error.
CycleCount( )(0x17)
Description: Returns the number of cycles the battery has experienced. The mAh value of each count is
determined by programming the Cycle Count Threshold value in DF 0x37-0x38. The bq2085 saves the cycle
count value to Cycle Count DF 0x0c-0x0d after an update to CycleCount( ).
Purpose: The CycleCount( ) function provides a means to determine the battery wear. It may be used to give
advance warning that the battery is nearing its end of life.
SMBus protocol: Read word
Output: Unsigned integer—count of total charge removed from the battery over its life.
Units: cycle
Range: 0 to 65,534 cycles; 65,535 indicates battery has experienced 65,535 or more cycles.
Granularity: 1 cycle
Accuracy: Absolute count
DesignCapacity( ) (0x18)
Description: Returns the theoretical or nominal capacity of a new pack. The DesignCapacity( ) value is
expressed in either current (mAh at a C/5 discharge rate) or power, (10 mWh at a P/5 discharge rate) depending
on the setting of the BatteryMode( ) CAPACITY_MODE bit.
Purpose: The DesignCapacity( ) function is used by the SMBus host’s power management in conjunction with
FullChargeCapacity( ) to determine battery wear. The power management system may present this information
to the user and also adjust its power policy as a result.
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