The Good: The Fremo Evo offers outstanding battery life or on-the-go listening with the Amazon Echo Dot, and it's a cinch to use, too. The Bad: The design isn't as clean or uniform as what you're used to with the Echo Dot, and you'll need to manually plug and unplug the battery as you move the speaker around. The Bottom Line: This is a sensible, affordable upgrade for the Echo Dot that enables unplugged, voice-activated Alexa access wherever you like. \t \t \tThe Amazon Echo Dot is a pint-size, puck-shaped version of the original, full-size . It's a low-cost access point for the that can connect with external speakers via or via line-in jack, but it doesn't have a built-in battery. That means that you'll need to keep it plugged in -- and that you can't take it with you for room-to-room listening on the go. \t \t \tThe Fremo Evo wants to help you change that. At $35, or \u00a345 in the UK, it's a battery base for the that lets Alexa go unplugged for up to a stated six hours of battery-powered playback. Combine that with the $50\/\u00a350 you'll spend on an Echo Dot, and you're looking at a portable, voice-activated Alexa speaker for about 35 percent less than what you'd spend on Amazon's own battery-powered Alexa speaker, the . \t \t \tThat's a good deal (especially in the UK, where the Tap isn't even available), but keep in mind that the Dot has by far the weakest sound quality of Amazon's Alexa speakers -- barely much better than the speakers in your phone. And, though you can't activate it with your voice, \tFabriq's third-party Alexa speaker offers the same portable approach complete with better sound and a better design -- all for just $50 flat. \t \t \tStill, the Evo worked exceptionally well in my tests, with battery life that far exceeds the stated six hours of promised playback. It isn't quite as convenient as the Tap, but people who already own an Echo Dot and just want to take Alexa out on the porch with them every now and then should love this thing. \t \t \tThe Evo keeps it simple -- just set the Echo Dot on top of it and connect the two using a dual-pronged adapter. You'll power it using your existing Echo Dot cable, then unplug whenever you want to take your speaker somewhere else. \t \t \tThe Evo comes in both white and black to match the color of your device, but it still compromises the Dot's clean, uniform design somewhat. Rigid teeth around the top of the battery form a sort of crown that the Dot sits in -- they're designed to prevent the battery from blocking off the speakers around the Dot's bottom rim. They work as promised, ensuring that the sound still gets out, but they also look a little janky compared with a plain Dot.