BQ27Z561-R1: temperature filter

Hello Ryan,

I'm not sure I understand the question, the gauge shouldn't report out -273 deg C, it may be due to other external influence on the TS pin or firmware reset, etc. Can you explain the situation further?

Sincerely,

Wyatt Keller

Wyatt,

This is form below issue we discussed before. It seems an internal silicon issue. Customer wants to do more test , thus we still didn't do ABA swap test.

I attached log below. You can see Line 43,  -271.9 C. (You can find more in the log)

Customer wants to know if only one occasional abnormal temperature, can our algorithm filter it out to guarantee our algorithm robust?

https://e2e.ti.com/support/power-management-group/power-management---internal/f/power-management---internal-forum/1114192/bq27z561-fcc-jump-after-fc-set/4150524#4150524

4428.FCC Jump issue.xlsx

Hello Ryan,

It looks like most of these may just be communication errors, the random temperature readings along with many of the other values being read fluctuating should not have an impact on the actual gauging algorithm.

The main issue to me from the logs is the Ta and Tk I mentioned before, which are consistently maxed out and will lead the gauge to miscalculate the thermal conditions of the battery when it calculates VCT and other gauging parameters like FCC. What were the results from manually adjusting these on the "bad silicon"? I would use the ABA swap to confirm it is following the gauge hardware and not the SREC.

Sincerely,

Wyatt Keller