In our PCB design, in many cases the LTC4015 doesn't start charging (sometimes it does).
The battery is 4 cells LiFePO4, same problem with "LiFePO4 Programmable" and "LiFePO4 Fixed Standard Charge".
A 10K NTC is connected, with a 10K bias resistor (register 0x40 reads 0x5547).
When it doesn't start charging:
bit bat_missing_fault=1 (register 0x34 = 0x0002). The battery is connected, I measure 13.3V on BATSENS pin.
when removing input power, register 0x34 = 0x0100 (suspend).
when re-applying input power, register 0x34 = 0x0002 (battery missing).