@slymonkey according to this [[Topic:Bose SoundSport Free wireless]] the batteries are LR44 batteries. The batteries that actually fit like [https://www.ebay.com/itm/185623983127?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1o3PGjCulRdWyaI-iZ5vyxA18&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&mkscid=101&itemid=185623983127&targetid=1584571731043&device=c&mktype=&googleloc=9027105&poi=&campaignid=15275224983&mkgroupid=131097072938&rlsatarget=pla-1584571731043&abcId=9300697&merchantid=112082348&gclid=EAIaIQobChMIh67W8pvI_QIViStMCh3JLAuxEAQYAiABEgIPDPD_BwE|show here] are pretty expensive. All you need is a pair [https://www.amazon.com/HQRP-Soundport-Headphones-Bracelets-Necklaces/dp/B0851NYNDV|of these] and solder your own pigtails if needed.