I bought one of these a couple years ago and it still lasts 12+ hours streaming internet radio from my iPad at work. Sounds great for background music in a shop.

Soundcore Anker Motion Boom Outdoor Speaker with Titanium Drivers, BassUp Technology, IPX7 Waterproof, 24H Playtime, App, Built-in Handle, Portable Bluetooth Speaker for Camping, Pool, Beach, Backyard a.co/d/7ptVcCe