X-Dragon Direct via Amazon offers its X-Dragon 10,000mAh Dual-USB Portable Solar Battery Pack in Green or Orange for $32.99 $31.99. Coupon code "JH4FPEL4" drops it to $23.09 $22.39. With free shipping, that's the lowest price we could find by $4. This water-resistant battery pack features four foldable solar panels, two USB smart-charging ports, and an LED light with three settings. Deal ends May 31.