I'm using AD8218 as battery current monitor. I'd made reference design but has a wrong output value. R14 is shunt precision resistor - 0.01 Ohm. AKBI and AKBO are connected to charger and 12V battery. Output pin 5 everytime equal 5.32V at any case. R14 voltage drop is from 0 till 60mV - voltage on output didn't changes.
As I understood from datasheet, internal LDO clamps output voltage with value 5.2V. It looks like AD8218 didn't seen +5v power supply and feed from IN+ pin.