Other Parts Discussed in Thread: BQ25896
Hello,
1. In our IoT Application, The power source to the IoT device is cut off every night. The Power source is a 5V adapter (non USB).
We wanted to continue streaming data until the battery died. But in doing that, around 20% of our devices do not recover after the power source comes up in the morning.
This is the flow:
1. Power Source (VBUS) turns off.
2. System draws power from the battery.
3. VBAT discharges to below 3V.
4. VSYS stops regulating (VSYS fluctuating between 1.3V to 0V)
5. There is 3.8V buck boost (TPS63020DSJ) at the output of BQ24296 which also stops regulating its own output voltage.
6. Eventually system dies.
7. Power Source (VBUS) comes back on.
8. System still does not start.
9. We unplug the battery - unplug the power source - re-connect the power source - the system comes back up - then connect the battery and the usual charging cycle begins.
These are our register values:
bq2429x_i2c_register_write(bq2429x_INPUT_CTRL_ADDR, 0x07);
bq2429x_i2c_register_write(bq2429x_POWERON_CTRL_ADDR, 0x1F);
bq2429x_i2c_register_write(bq2429x_CHARGE_CUR_CTRL_ADDR, 0x60);
bq2429x_i2c_register_write(bq2429x_PRECHARGE_CTRL_ADDR, 0xFF);
bq2429x_i2c_register_write(bq2429x_CHARGE_VOL_CTRL_ADDR, 0xB2);
bq2429x_i2c_register_write(bq2429x_CHARGE_TERM_CTRL_ADDR, 0x8C);
bq2429x_i2c_register_write(bq2429x_BOOST_THERMAL_CTRL_ADDR, 0x73);
bq2429x_i2c_register_write(bq2429x_MISC_CTRL_ADDR, 0x4B);
2. Is there a way we can know that the battery is gonna hit the BATLOWV and we turn off the BATFET so that the battery does not go into deep discharge.
(Right now we are forced to cut the BATFET off as soon as we detect PG = 0. We do not have a coulomb counter)
Thanks,
Shiv
