Snom M3 Replacement Battery 3.7V 900mAh Li-ion

Snom M3 / M9 Series — 3.7V Li-ion Replacement Battery (00001595)

This 3.7V, 900mAh lithium-ion battery replaces the original pack in the Snom M3, M9, M9R, and M9R-HC cordless DECT handsets. It matches the OEM voltage and physical dimensions (53.13 × 33.96 × 4.77mm), so it seats correctly in the handset battery compartment. When the original cell degrades and talk time drops noticeably, this is the direct replacement.

• M3, M9, M9R, and M9R-HC fit: These handsets share the same battery footprint, connector orientation, and 3.7V supply rail. No modification is needed — the cell slots in and the BMS handshake completes normally with the base station charge circuit.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the M9 platform. The BMS accepted charge from the base station cradle on the first insertion, voltage climbed steadily to 4.2V, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• First charge after installation: Place the handset in the base cradle immediately after fitting this battery and leave it for a full 16 hours before use. Li-ion cells shipped in partial state of charge need that initial full cycle to calibrate correctly with the handset's charge management circuit.

Talk time shorter than the original battery after replacement

A fresh Li-ion cell often delivers slightly less usable capacity in the first one to three cycles. The handset's charge circuit hasn't yet mapped the new cell's full charge curve. Run two or three complete charge-and-use cycles — each time, use the handset until it signals low battery, then return it to the cradle for a full charge. By cycle three, capacity stabilises at the rated 900mAh.

Base station shows no charge light or flashes an error after battery swap

This happens when the replacement cell arrives from storage at a voltage below the base station's charge acceptance threshold — typically below 3.0V. The cradle interprets a deeply discharged cell as a fault rather than initiating a recovery charge. Connect the handset to a USB power source using a compatible cable for 10–15 minutes to raise the cell above 3.2V, then return it to the base cradle. The charge indicator should then activate normally.