Other Parts Discussed in Thread: BQ25713, PMP40441,
Hi, we have implemented the BQ77915 battery protection IC along with the BQ25713 charge controller for our product. Our schematic was largely based off of the PMP40441 reference design for a USB-C charging solution for a 4-cell lithium ion battery.
We are seeing an issue where battery assemblies are draining to a much lower voltage than the undervoltage protection voltage threshold given in the BQ77915 (2.9V*4=11.6V). A few of our battery assemblies have shown that they are drained down to ~2.5-4V across the entire assembly (4 series lithium ion cylindrical cells). When we use a power supply + voltage divider to test the under voltage protection, we find that it properly closes the discharge FET and lower current draw to ~600uA.
I've attached a schematic of our charge and protection circuits for review. Please let me know if any additional information is required.