I have an iPhone 6s and an iPad Air. I travel a lot and of course my ambition is to pack as efficiently as possible. So I thought, why bring a charger for my iPhone 6s and the iPad Air charger when both chargers seem to work interchangeably. However, I don't want to risk damaging either device as maybe the chargers are using different current configurations. Is it risk free to use one of the chargers as the universal charger for both my devices? As for charging speed, I don't care, just as long as I don't risk damaging anything.