Electric-assist bicycles, electric scooters—complete vehicle with battery: UN 3481; battery shipped separately: UN 3480. Electric tools, garden tools—battery and body packed together or separately; applicable packing instructions differ. 3C products, wearables, power banks—power banks are treated as standalone batteries (UN 3480).
Full explanation and HS code list: https://patisco.com/zh/eu-check/lithium-battery-shipping Use HS codes to check which EU regulations apply to you: https://patisco.com/zh/eu-check