BQ27425-G1 Datasheet, PDF (13/32 Pages) Texas Instruments – System-Side Impedance Track™ Fuel Gauge With Integrated Sense Resistor

bq27425-G1
www.ti.com
SLUSAI6 – NOVEMBER 2011
NominalAvailableCapacity( ): 0x08/0x09
This read-only command pair returns the uncompensated (less than C/20 load) battery capacity remaining. Units
are mAh.
FullAvailableCapacity( ): 0x0a/0x0b
This read-only command pair returns the uncompensated (less than C/20 load) capacity of the battery when fully
charged. Units are mAh. FullAvailableCapacity( ) is updated at regular intervals, as specified by the IT algorithm.
RemainingCapacity( ): 0x0c/0x0d
This read-only command pair returns the compensated battery capacity remaining. Units are mAh.
FullChargeCapacity( ): 0x0e/0f
This read-only command pair returns the compensated capacity of the battery when fully charged. Units are
mAh. FullChargeCapacity( ) is updated at regular intervals, as specified by the IT algorithm.
AverageCurrent( ): 0x10/0x11
This read-only command pair returns a signed integer value that is the average current flow through the sense
resistor. It is updated every 1 second. Units are mA.
StandbyCurrent( ): 0x12/0x13
This read-only function returns a signed integer value of the measured standby current through the sense
resistor. The StandbyCurrent( ) is an adaptive measurement. Initially it reports the standby current programmed
in Initial Standby (default = -10mA), and after spending some time in standby, reports the measured standby
current.
The register value is updated every 1 second when the measured current is above the Deadband ( = ±5mA) and
is less than or equal to 2 x Initial Standby (default = -10mA). The first and last values that meet this criteria are
not averaged in, since they may not be stable values. To approximate a 1-minute time constant, each new
StandbyCurrent( ) value is computed by taking approximate 93% weight of the last standby current and
approximate 7% of the current measured average current.
MaxLoadCurrent( ): 0x14/0x15
This read-only function returns a signed integer value, in units of mA, of the maximum load conditions. The
MaxLoadCurrent( ) is an adaptive measurement which is initially reported as the maximum load current
programmed in Initial Max Load Current (default = –500mA) . If the measured current is ever greater than
Initial Max Load Current, then MaxLoadCurrent( ) updates to the new current. MaxLoadCurrent( ) is reduced to
the average of the previous value and Initial Max Load Current whenever the battery is charged to full after a
previous discharge to an SOC less than 50%. This prevents the reported value from maintaining an unusually
high value.
AveragePower( ): 0x18/0x19
This read-only function returns an signed integer value of the average power during battery charging and
discharging. It is negative during discharge and positive during charge. A value of 0 indicates that the battery is
not being discharged. The value is reported in units of mW.
StateOfCharge( ): 0x1c/0x1d
This read-only function returns an unsigned integer value of the predicted remaining battery capacity expressed
as a percentage of FullChargeCapacity( ), with a range of 0 to 100%.
IntTemperature( ): 0x1e/0x1f
This read-/write-word function returns an unsigned integer value of the internal temperature sensor in units of 0.1
K measured by the fuel gauge. If OpConfig[WRTEMP] = 0, this command will return the same value as
Temperature( ).
Copyright © 2011, Texas Instruments Incorporated
13