A4C offers the Chromo 2,200mAh Portable Backup Battery 2-Pack in five color combinations (Black/Pink pictured) for $12.95 with free shipping. That's $6.48 per battery and the lowest total price we could find for this quantity by $7, although we saw a 2-pack for a buck less last month. Each battery charges and provides backup power to USB input-compatible devices, including iPhone, iPod, and most other current smartphones. Cables are included.