An auxiliary device case for portable electronic devices provides physical protection from abrasion and mishandling. The device case includes an integral power converter module with small form factor. The power converter module is provided to power and recharge the internal batteries of the portable electronic device, and is stored within the case when not in use. The power converter module is removable from the case for connection to a wall power receptacle and is connected to the case by means of a retractable cord. The power converter module may include retractable blades and a hinged cord attachment to minimize the overall volume when stored within the case.