I'm implementing new design with MP2617B. VSYS signal is bad with battery disconnected. See picture (Green = Vin, Orange = VSYS).
Vin = 5,12V, VSYSmax = 3,92V, VSYSmin = 2,40V, battery disconnected.
Without load and battery disconnected, VSYS = 3,69V even if I use SYSFB feedback to reach 4,2V (R6 = 26,7k, R7 = 10k).
Battery connected, charger works well.
What could happen ?