Solar lipo charger: circuit design and validation
If your Buck converter does not manage a soft start, it is possible that to ODC turns off the OD gate voltage = G2.
Meaning the overdischarge current is tripped.
For Discharge battery connection to Buck grounds both external gnd FETs need a &gt;=3.2V high gate voltage satisfied by the protection IC Logic so bypassing them will also block the ODC protection.
Check your CSI R1 value for its threshold to be above your surge start, unless there is a cap fix.(?)
Check for OD and OC to be high to start, and what condition might turn off the OD gate.  Both gates need = 3.7V to drive the FETs to enable the battery to Gnd. While charging should disable the load so that CC cutoff is achieved (I think) . OD= “0”, OC=“1”
(Someone correct my answer if I am wrong)
Add PIN numbers that are missing on your schematic and verify they are correct.
Measure that start surge current and voltage.


I have never used this circuit before.
Try a small then large cap from CSI to Vss and use the smallest size that works.