Hello everyone. I am in the process of testing a BQ25505 using the EV KIT and noticed that the device is not shutting down battery charging when \EN is pulled up to VBAT_SEC under certain conditions. Any input is appreciated.
Test setup description:
- Simulating solar panel with bench power supply. VPS = Voc = 4.9V. Current limit set to 50mA (per the panel spec: 50mA @ 3.6V).
- Added a 72 Ohm series resistor to the output of the power supply to simulate panel output resistance.
- Set VBAT_OV to 3.586V (LiFePO4 battery) using a 6.49M and 6.65M resistor (used the excel spreadsheet to calculate values).
- Connected VBAT_PRI to GND (no primary battery used)
- VSTOR is shorted to VBAT_SEC (no need for undervoltage protection, and have high current transient loads)
Test process:
1. Charge battery to VBAT_OV, confirm that battery voltage stops at programmed voltage: ok
2. Change jumper pin on ev kit to move \EN from GND to VBAT_SEC: battery voltage starts increasing, current into VBAT is about 10mA
3. Drop Power supply voltage from 4.9 to 4V: charging shuts down.
