iFixit sells a replacement battery for $25 and has the instructions for replacing it on their site: https://www.ifixit.com/Guide/Logitech+MX+Master+3+Battery+Re

iFixit sells a replacement battery for $25 and has the instructions for replacing it on their site: https://www.ifixit.com/Guide/Logitech+MX+Master+3+Battery+Replacement/145542 https://www.ifixit.com/Guide/Logitech+MX+Master+3+Battery+Re...