Amazon.com: Synergy Digital Remote Control Battery, Works with Logitech Harmony 900 Pro Remote Control, (Li-Ion, 3.7V, 950 mAh) Ultra High Capacity Battery : Electronics
CS Remote Control Battery for Logitech Harmony One 720 Pro 880 Pro 890 Pro 900 Remote 785 880 885 89 Fits 1903040000 M36B M41B
Kastar Battery LCD USB Charger for Logitech Harmony 895 Harmony 900 900 Pro | eBay
R-ig7 Battery Dvisi 950mah Rechargeable Lithium Ion Bateria For Loh880 Logitech Harmony One 900 720 850 880 885 890 Pro H880 - Digital Batteries - AliExpress
foone🏳️⚧️ on Twitter: "I'm trying to get this Logitech Harmony 900 remote working, but it keeps telling me the battery level is extremely low... https://t.co/v3CRE2BUD9" / Twitter
Kastar Battery LCD USB Charger for Logitech Harmony 895 Harmony 900 900 Pro | eBay