My wife was using the only iPhone charger in the house so I figured, hey, I'll charge my iPhone with my fancy new iPad charger. I plugged it in for over 4 hours, and that got me from 16% to 54%. I found this odd, so I unplugged it and plugged it into the iphone charger, where it went from 54% to 75% in about 15 minutes, more or less the expected rate. Is this normal behavior? Should I not be charging my iPhone with my iPad charger? Thanks in advance.