Well, its always advised to use the... but I would say there's nothing much to worry about its a very less difference ! I don't think any problem is going to occur in a while !
Hey buy the Mi power bank without hesitation, it is awesome!
I got these yesterday, the 10,400 mah one.
It came 25% charged,
charges fully in 5.5 hours approx.
It charged my galaxy y (1100 mah) from 10% to 80% in half hour!