We use them on a Galaxy S6 and S7. They both have covers on them and we never take them off. I have a few of the OEM samsung chargers and a few aftermarket ones. Both of these phones support the fast charge method when they are plugged in directly but my QI chargers do not support that. Samsung does have a fast charge QI charger now as well but I have no idea on the cost of them. I like the idea because it does save the port from plugging/unplugging all the time and really could not be more convenient then laying them down on the charging pad