Aukey 20W Solar Charger, $39 with code AUKEYPB2 | 28W Solar Charger, $48 with code AUKEYPB3

Whether you like to spend a lot of time outdoors, or just want to be prepared for extended power outages, these Aukey solar chargers can juice up two USB-powered devices at once using nothing but the sun.

The cheaper model is more compact, but can only put out 3.1A across the two ports (or 2.4A on a single port), while the larger model can output 2.4A simultaneously on each port.