Staples offers the Mophie Juice Pack Helium 1,500mAh Charging Case for iPhone 5 / 5s in Silver, model no. 93273VRP, for $49.99. Coupon code "86128" drops it to $39.99. With free shipping, that's the lowest total price we could find by $10, although we saw it for $2 less in May. This 1,500mAh battery pack provides up to six hours of talk time or up to seven hours on the Internet. Deal ends October 8.