Plantronics CS50, SC55, and CS50-USB Headset Replacement Battery - Artisan Power
3.7V Battery Replacement for Plantronics Backbeat Go 2 Earphone Headset Li Ion Lithium Rechargeable Accumulator+Track Code|Digital Batteries| - AliExpress
Savi W710/W720 and CS510/CS520: How to Replace the Battery | Poly, formerly Plantronics & Polycom
Spare Battery for Plantronics Headsets | Onedirect.co.uk
Replacement of battery on CS520 Plantronics - YouTube