Somno Medics SomnoScreen SSC051 3.7V Replacement Battery

Somno Medics SomnoScreen Type SSC051 — 3.7V Li-ion Replacement Battery (110686-O)

This is a 3.7V 3400mAh Li-ion replacement battery for the Somno Medics SomnoScreen type SSC051 portable sleep screening monitor. It replaces OEM part 110686-O and fits the SSC051 diagnostic unit used in overnight sleep studies and apnea detection. Capacity and voltage match the original cell specification from product data.

• SSC051 platform fit: The SomnoScreen SSC051 uses a single-cell 3.7V Li-ion pack with a proprietary BMS handshake that verifies cell chemistry at boot. This replacement cell matches that voltage rail and connector, so the device recognises it correctly during the power-on self-test sequence.
• Bench tested on actual hardware: We cycled this cell through the SSC051's charge-discharge profile and monitored BMS response across the full state-of-charge range. The protection circuit handled low-voltage cutoff and overcharge limits within the OEM thresholds on both test units.
• Post-swap startup protocol: After installing this battery, allow the SSC051 to complete its full power-on self-test without interruption. The BMS runs a verification routine at startup that flags any mid-sequence power break as a battery fault — that fault flag persists until the next complete reboot cycle.

Why the SSC051 may not complete its boot sequence on a new battery

The SSC051 runs a BMS learn cycle during its first few charge-discharge passes on a new cell. Until that cycle completes, the device's charge controller applies a conservative current limit and may stall the boot sequence if it detects state-of-charge uncertainty. This is not a faulty battery — it is the device behaving correctly with an uncalibrated cell. Run one full charge to 4.2V and one full discharge under normal operating load before using the unit clinically. After that first cycle, boot behaviour normalises.

Charge indicator stalls below 100% on first charge after battery swap

On the first charge after a cell swap, the SSC051's charge IC applies a reduced current ceiling because the BMS has not yet profiled the new cell's internal resistance. The indicator may hold at 85–95% for an extended period before the final constant-voltage top-up completes. Do not interrupt this charge — pulling the cable early leaves the cell below the 4.1V threshold the device needs to pass its self-test on next boot. Let the charge cycle run to termination and confirm the indicator reaches 4.2V before clinical use.