Gauging Parameter Calculator: Optimize room and low temp performance Impedance Track gauges
Gauging Parameter Calculator – Optimize room and low temperature performance for Impedance track gas gauges (GPCRB) is a math calculation tool that helps the battery designer to refine the Impedance Track battery gauge parameters for a given battery profile. Depending on the input log file, it provides optimized calculated values of for parameters like Qmax, Ra, thermal coefficients and other internal chemistry data.
Chemistry IDs match must be obtained and correct chemistry must be programmed into the gas gauge prior to collecting data for room and low temperature performance optimization.
For very low temperature operations, typically below 5C, system temperature distribution can deviate from lab conditions, and so resistance temperature compensation parameters need to be adjusted based on in-system or similar conditions data. This tool provides an output file with optimized chemistry information that can be programmed into the gauge for best performance. While Ra and Qmax parameters can be learned by the gauge automatically through performing traditional optimization cycle, this tool also allows to obtain thermal model parameters that do not update in single cell (handheld) gauges, which help with high rate tests accuracy. It also provides Ra0_charge value (helps to reach 100% SOC during charge more accurately), which does not self update and is not yet available in older chem IDs. In addition, this tool can utilize the log file from optimization cycle if some problems with learning Qmax and Ra have been observed, or to obtain all golden GG parameters by using Arbin or Maccor testers on a bare cell without using an actual EVM.
For optimized internal chemistry data, the tool requires a log of discharge test at low temperature; the test must be performed using a temperature controlled chamber. To combine with Optimized room temperature performance for IT gas gauges, the tool will also require a log file at room temperature of charge / relaxation / discharge /relaxation test performed under load and heat exchange conditions similar to actual device, or ideally inside the actual device.
A *.gg.csv file must also be provided. Information from this file is used by the tool to decide the parameters to optimize. The tool will output a gg.csv file with optimized parameters. The output file can be imported to data flash.
The tool will produce a chemdat12 or *.chem file independent of the initial *.gg.csv file. Chemdat12 must be programmed using bqStudio chemistry GUI before the *.gg.csv file, in order to provide both improved resistance temperature compensation and learned values
The battery pack must use one of TI’s Impedance Track(IT) algorithm based fuel gauges. It accepts log files in the format specified in the instruction manual. The log files can be created by using TI’s Battery Management Studio (bqStudio) software with the specific Evaluation board connected through USB, or by any battery tester with data logging capabilities like Arbin or Maccor. External equipment is required for charge and discharge. For accurate calculations it will also require additional parameters of the battery pack setup. The output information will be emailed as a text file containing the parameter values to be programmed in data flash. If an exported Data Flash gg.csv file is included, the output will contain a gg_out.csv that has the updated information. The data can be imported and programmed into Data Flash using bqStudio to create a golden image that can be used in mass production of battery packs.
If bqStudio is used for logging, an EV2300 or EV2400 PC interface board is required to interface to the gas gauge, and a PC USB cable is required for communication with a PC. Both can be ordered online at http://power.ti.com. Windows™-based PC software is available online as well. With the EV2300 or EV2400 interface board and software, the user can read the data registers, program the chipset for different configurations, log cycle data for further evaluation, and evaluate the overall functionality of the solution under different charge and discharge conditions.
This tool does not require the purchase of a separate Mathcad™ license.
Depending on the specific gas gauge product, bqStudio software may provide a packaging utility to create the zip file from the log files.
Note: This tool is not applicable to Compensated End of Discharge Voltage(CEDV) gauges. This tool is only for firmware that supports Resistanec temperature optimization/ 2 exponent Rb. Examples of supported gauges are bq40z50-R1, bq27541.
Download the instruction manual that applies to your battery pack and collect data per instructions.
This will yield a packaged zip file.
For Chemistry ID matching of Impedance Track(IT) gas gauging:
Upload the zip file.
Login is required.
Gauging Parameter Calculation chemistry ID match report to be emailed to you.
View a sample report.
Email firstname.lastname@example.org for support issues related to use of this page.