I am using a bq20z65 and am encountering permanent errors during thermal cycling of my battery. I have a temporary thermal cutoff device in the pack that trips during the cycle. When the device trips, the gas gauge is no longer able to read one of the cells so it trips SUV, CIM_R, and the reserved permanent failure bit. I tried setting the CIM_R threshold to 5000 and the SUV threshold to 0 to avoid getting these errors (I know this should effectively make both of these features useless). The CIM_R no longer trips but the SUV and the reserved field still do.
Why does the SUV flag get set if the SUV threshold is set to 0? Is it possible that noise on the line is driving that voltage below 0 and thus setting that flag even at 0? I would be surprised if negative noise persisted for 2 seconds. Does anyone know what the reserved permanent failure field is?