A:Answer Hello there!
Thanks for the question. The SoundLink Wireless Around-Ear headphones II use a rechargeable non-replaceable lithium-ion battery. We expect the battery to last for years to come but should you need any assistance with that please feel free to contact our Bose Support by navigating to this page here for contact details: http://bose.life/2qwENj4. Select your country, scroll down, click "Contact us"
Thanks again for your interest in our Bose products!
Very best regards,
Mohsin-Bose Support