Amazon.com: Synergy Digital Cell Phone Battery, Works with Nokia Lumia 520 Cell Phone, (Li-ion, 3.7, 900mAh) Ultra High Capacity, Compatible with Nokia BL-5J Battery : Cell Phones & Accessories
Nokia Lumia 520 Repair - Back Cover and Battery Removal - YouTube
File:Nokia Lumia 520 with Battery.jpg - Wikimedia Commons