How to replace the battery in your iPhone 5s - iFixit Repair Guide
Amazon.com: IBESTWIN 3.8V 1440mAh Replacement Battery for iPhone 5 A1428, A1429 and A1442 with Replacement Tool Kits, Adhesive Strip (Not for IP 5S or 5C)-3 Years Warranty : Cell Phones & Accessories
Amazon.com: (Upgraded Version) Battery for iPhone 5S/5C, BOANV Ultra High Capacity New 0 Cycle iPhone 5S/5C Battery Replacement with Professional Replacement Tool Kits : Cell Phones & Accessories