I have a k38021 ultra portable model and it works great as a portable charger for my EVO. I use a belkin USB splitter and this charges both batteries flawlessly (using two stubby usb chargers). Plus the Kensington wall jack is a standard USB AC adapter so it works as well righ from the outlet. A nice bonus for those of us who got our EVO from intellicig (in the UK) as that mains is the UK style, the Keningston is a sleek replacement with fold in prongs. Awesome accesory, great find, thanks for the thread.