The venerable Will Smith said it best, “Summer, summer, summertime. Time to sit back and unwind.” The sun is out and the tunes should be blaring. That’s where the Eton Rukus Solar comes in. This speaker system streams music from your phone via Bluetooth or 3.5mm cable while keeping its battery charged with a massive solar panel array. What’s more, a USB port allows the Rukus Solar to charge your phone, too.The Rukus Solar is a fantastic outdoor audio system. Well, that is, aside from two curious design decisions.