Amazon.com: Synergy Digital Remote Control Battery, Compatible with Logitech Harmony Ultimate One Remote Control, (Li-ion, 3.7V, 1050mAh) Ultra High Capacity, Replacement for Logitech 533-000083 Battery : Electronics
How to Replace Battery in Harmony Remote Remote Touch / Ultimate / Elite - YouTube
Amazon.com: GAXI Battery Replacement for Logitech 915-000198 Compatible with Logitech Harmony Touch, Harmony Ultimate, Remote Control Battery : Electronics