The RAVPower 20000mAh portable solar charger and external battery pack is down to $25.09 on Amazon thanks to this link that takes 30% off the price and an extra $5 off on-page coupon. You may need to go to the product page after you add the product to your cart to see the coupon.
You can charge two devices at once, and with the huge capacity you'll be able to charge them multiple times.
$25.09 $43 $18 off
The solar power battery pack is built to survive even your extreme activities. It can charge two devices at once with the dual USB outputs, and the 20000mAh capacity means you can charge multiple times before running out of juice. Even while charging, you can continue to refill the battery with the solar panel. When you aren't anywhere near an AC outlet or electricity, the solar panel can be a life saver. It has a built-in super bright LED light, too.
