BQ24295: VSYS-STAT not changing state while battery is discharging

Hi,

I did testing of BQ24295 charger circuit, as per our application feature  we want low power battery indication so for that I read I2C register REG08 – VSYS-STAT.

I have set VSYSMIN as 3.5V

But I cannot get VSYS-STAT bit high (logic -1) while battery gets less than 3.5V in discharge mode .

However,  VSYS-STAT bit changes to high (logic -1) when battery is fully drained. 

When again adaptor is plugged-in (battery is charging) that time this bit is high.

Can you tell me why VSYS-STAT bit is not changing in discharge mode (mean DC Adaptor is not present) as it does in charging mode (when DC adaptor is present)

Please also mention alternative solution of low battery measurement using register setting.

Here I mention my testing setup detail and I2C register setting.

1. Battery voltage = 4.2 V
2. Charging current = 500mA
3. Discharge current (output load ) = 450mA
4. Set Battery cutoff voltage = 3.0V
5. Set  Vsys Min voltage = 3.5V

I2C register setting:

#define REG00   0x72    //Input Source Control

#define REG01   0x3E    //Power-On Configuration

#define REG02   0x00    //ChargeCurrentControl

#define REG03   0x11    //Pre-Charge/TerminationCurrent

#define REG04   0xB2    //ChargeVoltageControlRegister  //B2

#define REG05   0x8C    //ChargeTermination/TimerControl

#define REG06   0x93    //BoostVoltage/ThermalRegulationControl

#define REG07   0xC0    //MiscOperationControl

 Regards

Atul