When we are away on the bike we have a number of 240v charged devises on tour with us:-
iPhone, iPad, Samsung S4 phone, Contour camera and 2 Sena SMH10.....so although they can all be charged individually with a 240v USB charger from an iPhone the process was quite protracted doing one devise at a time, carrying more than one charger was also a pain when travelling with 2 people for extend stays and packing is tight. We can and do charge on the bike if needed but I like to keep the cords to a minimum.
So enter eBay.......
$13 gets this
Charge 4 devises at once and all done before bed, packed and ready for the next day on the road.