If it is powered off, Samsung Galaxy Tab 2, it seems to charge fine. Only when it is powered on do I get a red "X" on the battery...when plugged into the computer. When the SGT2 is on and plugged into the wall power adapter the red "X" on the battery is not present. Whether wall charger or through the computer it charges fine...only when on does the computer charging not work through my experience on the SGT2. I also own the first generation SGT and it has the benefit of charging whether on or off in the wall or computer usb to charge. I hope this helps.