Why my iphone 7( I use it 3 days) charges too slowly?

Why my iphone 7( I use it 3 days) charges too slowly? - 1

Maybe apps running in the background

Either its the charger or possibly your charge port needs cleaned out

Happens if too many apps are running in the background. Close all the apps and turn off the data and you'll see it charge quicker. It also happens if there's a glitch in the firmware and a simple factory reset solves that problem.