SLUUA65E april 2014 – june 2023 BQ28Z610
The device now implements an updated version of the battery state-of-health (SOH), which is reported by the StateofHealth() command. In the previous version, the StateofHealth() was calculated using a special 25°C version of FullChargeCapacity as a fraction of Design Capacity. However, this calculation still included some parameters that were updated during operation based on the loading and use of the battery, separate from the battery status itself. This could lead to varying calculations of state-of-health for the same battery, depending on how the battery was used in system. The updated version of StateofHealth() addresses this by calculating a special SOH Full Charge Capacity, with the initial ambient temperature fixed at 25°C, using a current load specified by SOH Load Rate, and using the thermal model parameters, SOH Temp a and SOH Temp k.
The SOH Load Rate can be set to the typical current of the application, and it is specified in units of hour-rate (that is, Design Capacity/SOH Load Rate will be the current used for the SOH simulation). The SOH Temp a and SOH Temp k can be set to expected values for the system during operation. These data flash settings are used only for the StateofHealth() calculation. This SOH Full Charge Capacity is updated whenever ASOC and RSOC are updated. Because this implementation removes the variation of load current, temperature, and learned parameters, it is a better representation of the battery's state-of-health. The SOH Full Charge Capacity is available on the MAC command FCC_SOH().