DISCHARGE mode is exited and RELAX mode is entered when Current goes above (–)Quit Current threshold
for a period of Dsg Relax Time. CHARGE mode is entered when Current goes above Chg Current Threshold.
Time
Current
0
Chg Current
Threshold
Quit Current
(-)Quit Current
Dsg Current
Threshold
RELAX
Mode
CHARGE
Mode
Chg Relax
Time
RELAX Mode
DISCHARGE
Mode
Dsg Relax
Time
RELAX Mode
Figure 6-2. Gas Gauge Operating Mode Example
6.4 QMax and Ra
The total battery capacity is found by comparing states of charge before and after applying the load with the
amount of charge passed. When an applications load is applied, the impedance of each cell is measured by
comparing the open circuit voltage (OCV) obtained from a predefined function for present state-of-charge with
the measured voltage under load.
Measurements of OCV and charge integration determine chemical state-of-charge (SOC) and Chemical
Capacity (QMax).
The BQ28Z610-R2 acquires and updates the battery-impedance profile during normal battery usage. It
uses this profile, along with state-of-charge and the QMax values, to determine FullChargeCapacity and
RelativeStateOfCharge specifically for the present load and temperature. FullChargeCapacity reports a capacity
or energy available from a fully charged battery reduced by Reserve Cap-mAh or Reserve Cap-cWh under
the present load and present temperature until Voltage reaches the Term Voltage for a period of Term V Hold
Time.
Gauging www.ti.com
38 BQ28Z610-R2 SLUUCO0 – APRIL 2022
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated
To Next Page
Loading...
