RAVPower 15000mAh Portable Dual USB Solar Charger $15 at Amazon
Amazon with RAVPower Official has the RAVPower 15,000mAh IPX4 Splashproof Dustproof Portable Dual USB Solar Charger Power Bank Battery Pack with Flashlight (US-RP-PB-003;
black or
orange/yellow) for $35 - $20 off coupon (check "extra savings" box) =
$15 with free shipping on $25+ or with Prime.
Original Source of Info