Logitech Harmony One Remote Battery Replacement - YouTube
Battery for Logitech Harmony One 720 780 785 880 885 890 895 900 R-IG7 — Battery Mate
Amazon.com: Youejoeq (2-Pack) logitech r-ig7 Battery Replacement for logitech Harmony one 900 850 880 885 890 Pro H880,fit Part no R-IG7 190304-0000 f12440023 : Electronics
Best Buy: Logitech Harmony Ultimate One 15-Device Universal Remote Black 915-000224