Recently Apple have released a major update IOS 11.3 and one of the function added is battery health feature in which you can monitor the health of your battery whether it need to be replaced.  But the feature doesn’t work with replacement battery (not original apple  battery) and it doesn’t show the health of your battery. There is a way that you can monitor your battery health which is by downloading an apps called “BATTERY LIFE” and it works perfectly on my phone. I guess those who have replacement battery like I do will not enjoy this feature 🙁