Square Deals via Amazon offers the refurbished Mophie Juice Pack Plus 2,100mAh Charging Case for iPhone 5 / 5s in White (pictured) or Black for for $35 with free shipping. This battery case has a 4-LED status indicator and provides up to 10 hours of additional talk time or up to 50 hours for audio playback.

A 1-year warranty applies, although it's unclear who supports it.