USB Battery Charging 

Battery Charging Specification, Revision 1.2

If a USB device, hub or host support battery charging capabilities according to the Battery Charging Specifcation 1.2 the product must undergo the Battery Charging Specifcation 1.2 compliance plan. During USB compliance program all products will be validated if the product support this feature or not. If the product has a primary detection it will be required to perform all  Battery Charging 1.2 tests of the compliance plan.  
If the device charge their batteries but not according to Battery Charging 1.2 specification the tests not need to be performed, in that case make sure the device meet all power consumption requirements.