Other Parts Discussed in Thread: BQSTUDIO
Hello, I had a few questions about the FC Set%, values of QMaxPassedQ, Dod0PassedQ, and how SOC/FCC[Full Charge Capacity]/RC[Remaining Capacity) are updated during relaxation mode and charge mode:
1. The reference manual states, in the register description for the *Flags* register, that the FC bit represents the following:
" Full charge is detected. FC is set when charge termination is reached and FC Set% = –1 (see Section 3.7 for details) or StateOfCharge() is larger than FC Set% and FC Set% is not –1. True when set."
Section 3.7 lists the conditions that will consider the gauge to sense "Charge Completion", yet does not explain what FC Set % represents or how it is updated. Does anyone have any insight on this?
2. My understanding of the RC/FCC updates during discharge/charge are as follows. Please correct me if I am wrong:
a. During discharge, RC is updated every second using a voltage simulation that projects voltages at decrements 4% relative to the current DOD. These projected voltages derive from the projected OCV at the decremented DODx, which are corrected by the resistance at the decremented DODx, and the current running into or from the pack. The simulation iterates until the termination voltage is reached for discharge, and once this occurs, RCC is calculated to be: RC = (DODfin - DODstart) * Qmax, where Qmax is the maximum chemical capacity of the lowest capacity cell in the pack. FCC is updated at every grid point resistance update during discharge based on the delta between DOD0 before discharge was entered and QStart (DODCharge), the most recent updated RC, and the amount of charge integrated during the current discharge.
b. During charge, RC is just updated every second based on the current RC plus the integrated charge over the last second.
During charge, how is FCC updated? During relaxation, when a DOD update is made if the corrected OCV (correction based on calculated internal impedance of the cell at the current temperature and present current in the system) has changed in the last 100s (the interval at which OCV is updated after the relaxation wait period has elapsed), how does this modify the RCC/FC? Furthermore, if FC is based on the QMax of the lowest capacity cell, then how is it that FC and RCC are pack-level values rather than cell-level values?
3. If QMaxPassedQ is equivalent to 0, and DOD0PassedQ are equal to 0, does that mean that both the well relaxed condition (QMax is only updated in the well-relaxed condition. I am assuming that once it is reset to 0 it means that QMax has been recalculated) and the 30-minute relax wait period have passed? (DOD0 is only updated once 30 minutes in relaxation have elapsed). Furthermore, what does a value of -1 represent for these registers?
