This waterproof wireless speaker plays for 15 hours and costs $13
https://www.cnet.com/news/this-waterproof-wireless-speaker-plays-for-15-hours-and-costs-13/
A fairly basic-looking black brick with a nice touch of red embedded in the bezel, the 10-watt VTIN can play for up to 15 hours on a charge, according to the vendor. Its IPX6 rating means it can survive splashes or even a dunk. I particularly like the large, easy-to-read controls along the top. If you like bass, just press the Bass+ button to give it a boost.
I haven't tried this particular speaker, but I've listened to a few other VTIN models over the years and found them to be quite good. Meanwhile, well over 200 buyers collectively rated this 4.6 stars out of 5, and most of those ratings are legit, according to both Fakespot and ReviewMeta.