Amazon has the Anker 2nd Gen Astro3 12000mAh External Battery Charger for only $39.99 shipped (when you use the promo code: ASTRO32G at check out). That’s $60 off the list price and the lowest we’ve seen it for.
The Anker is powered by PowerIQTM technology that identifies each connected device and “speaks its language” (guaranteeing the fastest charge time for EVERY device). It also has 12000 mAh of capacity and an energy efficiency rate 10% above previous generation Astros and many current standard alternatives charges the iPhone six times. A “shake” starts a charge or displays the remaining power level. Also, with a sturdy construction and matte finish to withstand bumps and drops. Input: 5V / 1.5A
Over 700 Amazon Customers gave it 4.7/5 stars and left excellent reviews for it.