Logitech Harmony 880 Replacement Battery 3.7V 950mAh

Logitech Harmony 880 / 885 / 890 Series — 3.7V Li-ion Replacement Battery (190304-200)

This is a 3.7V, 950mAh Li-ion battery that replaces the original rechargeable cell in the Logitech Harmony 880, 885, 890, 720, and compatible Harmony remotes. It slots directly into the internal battery bay and connects via the factory wiring harness. The OEM part numbers this cell covers include 190304-200, R-IG7, NTA2340, and HHD10010, among others listed above.

• Harmony 800-series platform fit: The 880, 885, and 890 share the same internal battery format, connector pinout, and charge circuit. All three use this 3.7V cell on the same charging rail, so one SKU covers the range without any modification.
• Bench tested on actual hardware: We ran this cell through the Harmony 880 charge circuit and confirmed the protection board communicates correctly with the remote's onboard charger — no false fault states, no charge interruption at top-of-charge.
• Reassembly after battery swap: The Harmony 880 back panel uses friction clips that crack if pried from the wrong edge. Start at the top corner near the charging port and work down. Forcing the base corner first is the most common cause of a cracked housing during DIY battery replacement.

Why the Harmony 880 won't charge after sitting unused for months

Li-ion cells that drop below approximately 2.5V enter a deep-discharge state where the protection circuit locks out the charge path entirely. The Harmony 880's charger delivers a low-current pre-charge to recover cells in this state, but only if the voltage hasn't fallen below the BMS hard cutoff. If the remote shows no charging indicator at all after being left discharged, leave it on the cradle for 30–60 minutes before writing off the battery — the pre-charge stage is silent and shows no LED activity on some firmware versions.

Harmony 880 IR range dropping noticeably with a new battery installed

Short IR range after a battery swap usually means the cell voltage is sitting below the threshold the remote needs to drive the IR LED at full output. This happens when the replacement cell ships partially discharged — common with Li-ion cells in storage. Place the remote on its charging cradle for a full charge cycle before testing range. Once the cell reaches 4.1–4.2V, IR output returns to normal operating distance.