https://www.cnet.com/news/this-speaker-dock-makes-your-echo-dot-mobile-for-24/

Ever wish you could free your Amazon Echo Dot from the confines of its power cord? Maybe take it with you to the backyard or even the beach? You can, with a battery-powered speaker dock (and, of course, a Wi-Fi hotspot provided by your phone).

Most of the docks I've seen start at around $50, which makes this deal especially intriguing: For a limited time, and while supplies last, the Mokcao Power+ Cordless Speaker with Battery Base for Echo Dot is just $23.99 when you apply promo code 48WK6EH4.