Sunvalleytek via Amazon offers Amazon Prime members the RAVPower Element 10,400mAh External Battery Pack, model no. RP-PB07, for $32.99. Coupon code "BXS8G95M" cuts the price to $25.99. With free shipping, that's tied with our mention from two weeks ago and the lowest total price we could find by $9. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping adds $5.74.) It features 1-amp and 2.1-amp USB outputs and is compatible with iPhone, iPad, iPod, and many smartphones.