Part Number:BQ27426
Hello,
I have a few questions on using the BQ27426 gauge in production.
As per my understanding:
1. We should use the EVM kit to perform a learning cycle and then reconfigure the necessary parameters that matches our system application. A golden image file should then be created. This golden image file should ONLY be used during production as (usually) a brand new battery is installed in the device. Correct?
2. If the battery has been aged, the golden image file should not be applied as the data memory (Ra tables, Qmax) would not match with the aged battery. Correct?
3. Relating to (2.), Is it correct in saying that even if the golden image is applied to the aged battery, the gauge will, in-time, readjust itself to the profile of the aged battery.
4. Relating to (2.) and quoting from Figure 4. of quick start guide http://www.ti.com/lit/ug/sluubn3/sluubn3.pdf an alternative would be having the host periodically saving the Ra tables and other "learned parameters" into NVM. This way, if the gauge has gone through a POR, the latest saved data should be re-loaded into the gauge. What other "learned parameters" should the host save?I read the it is recommended to save Ra and Qmax.
5. The quick start guide also states that, at a minimum, Design Capacity, Design Energy, Terminate Voltage, and Taper Rate should be reconfigured in order for accurate gauging. Applying a golden image file can additionally improve the gauging accuracy. To this extent, does that mean the golden image file is optional?
6. Relating to (5.), from your experience, is there a large difference in gauging accuracy between a gauge that has been configured with the bare-minimum vs a gauge that as been applied with a golden image?
Thanks,
William