SLUUC54C February 2020 – March 2024 BQ27Z558 , BQ27Z561 , BQ27Z561-R2
The Ra table is part of the impedance profile that updates during discharge when gauging is enabled. The initial Cell0 R_a0...14 values should be programmed by selecting the correct chemistry data during data flash configuration. A chemistry database is constantly updating, and can be downloaded from the Gas Gauge Chemistry Updater product web page (http://www.ti.com/tool/gasgaugechem-sw). The initial xCell0 R_a0...14 values are a copy of the non-x data set. Two sets of Ra tables are used alternatively when gauging is enabled to prevent wearing out the data flash.
The Cell0 R_a flag and the xCell0 R_a flag indicate the validity of the cell impedance table for the cell.
Firmware updates these values: It is not recommended to change them manually.