Other Parts Discussed in Thread: BQ27426, BQ24192, BQSTUDIO, EV2400
Hi TI Team,
In our product for monitoring the battery we have used bq27426EVM-738 EVK and for charging the battery we have used bq24192EVM-021.
Both are connected with the STM32L5.
Setup information:
1. Fuel Gauge EVK
| BQ27426 FG EVK | Connections |
| Load+ (J6) | BAT pin of BQ24192 charger chip EVK(J2.1) |
| Load- (J7) | GND of BQ24192 charger chip EVK (J2.3) |
| Pack+ (J5.1) | Battery +ve |
| GPOUT (J2.2) | GPIO of STM32 EVK |
| BIN (J5.2) | NTC pin of Battery |
| Pack- (J5.3) | Battery -ve |
| SCL (J1.2) | SCL (J3.9) of BQ24192 charger chip EVK |
| SDA (J1.3) | SDA (J3.10) of BQ24192 charger chip EVK |
2. Charger chip EVK
| BQ24192 Charger Chip EVK | Connections |
| PG (TP5) | GPIO Pin of STM32EVK |
| STAT (TP10) | GPIO Pin of STM32 EVK |
| SCL (J3.9) | I2C SCL of STM32 EVK |
| SDA (J3.10) | I2C SDA of STM32 EVK |
| INT (J4.4) | GPIO Pin of STM32 EVK |
| CE (J4.2) | GPIO Pin of STM32 EVK |
| BAT (J2.1) | Load+ (J6) of BQ27426 FG EVK |
| VBUS (J1.2) GND (J1.1) |
DC Jack GPB |
Using this setup we have received the battery voltage, battery current and SoC value of battery successfully in STM32.
Observation:
1. When we charge the battery using charger chip EVK then SOC % gets updated accordingly.
2. When we discharge the battery using DC ELECTRONIC LOAD then the voltage is decreasing but SOC% remains stuck at one value (doesn't update in runtime).
For debugging purpose, I have checked the flag register and I received below values:
Flags Register:
| Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 | |
| High Byte | OT | UT | RSVD | RSVD | RSVD | RSVD | FC | CHG |
| Low Byte | OCVTAKEN | DOD CORRECT | ITPOR | CFGUPMODE | BAT_DET | SOC1 | SOCF | DSG |
Received 16 bit value : 0x1C8
1. Now the question is why the DSG bit is zero when I put the system in the discharging mode.
Please help me to resolve this issue.
Note: We have used 5000 mAH battery capacity and we have set the CHEM_ID as Profile B as per battery specifications.
