Application-Specific Information
38
SLUUBE8 – September 2018
Copyright © 2018, Texas Instruments Incorporated
Functional Description
2.8.2 First OCV Measurement
Upon power-up, an open-circuit voltage (OCV) measurement of the battery is made via the BAT pin. For
the best gauging results, the system load during the OCV measurement should not exceed a C/20
discharge rate of the battery.
Upon completion of the OCV voltage measurement,
BatteryStatus()[OCVCOMP]
is set.
2.9
Additional Data Memory Parameter Descriptions
2.9.1 Calibration
The calibration method requires a correction due to offset errors, using a number of samples to get a
statistical average for the golden image. The parameters of particular interest are listed in the following
sections.
NOTE:
Calibrate the gauge only when it is in FULL ACCESS UNSEALED mode.
2.9.1.1
CC Gain
CC Gain
sets the mA current scale factor for the coulomb counter. Use calibration routines to set this
value.
2.9.1.2
CC Delta
CC Delta
sets the mAh capacity scale factor for the coulomb counter. Use calibration routines to set this
value.
2.9.2 Coulomb Counter Offset (CC Offset)
This register value stores the coulomb counter offset compensation. It is set by automatic calibration of the
device.
2.9.3 Board Offset
This register value stores the compensation for the PCB dependent coulomb counter offset. It is
recommended to use characterization data of the actual PCB to set this value.
2.9.4 Int Temp Offset
This register value stores the internal temperature sensor offset compensation. Use calibration routines to
set this value.
2.9.5 Ext Temp Offset
This register value stores the external temperature sensor offset compensation. Use calibration routines to
set this value.
2.9.6 Pack VOffset
This register value stores the Pack voltage offset measured at the Pack pin. Use calibration routines to set
this value.
2.9.7 Internal Temp Model
Internal Model Coefficient 1 through 4 characterize the internal thermistor of the device. Do not modify
these values without consulting TI.