Otometrics Madsen AccuScreen 3.7V Compatible Battery 1800mAh

Otometrics Madsen AccuScreen — 3.7V Li-ion Replacement Battery (8-73-02400)

This 3.7V, 1800mAh Li-ion cell replaces the original battery in the Otometrics Madsen AccuScreen and AccuScreen TE (8-04-13900) portable audiometric screening devices. It matches the OEM voltage rail and physical footprint, including dimensions of 53.00 × 35.30 × 11.00mm. Capacity is drawn from product specification — 1800mAh / 6.66Wh.

• AccuScreen and AccuScreen TE compatibility: Both the standard AccuScreen and the TE variant share the same battery bay geometry, connector pinout, and BMS handshake protocol. The same 3.7V cell services both units without modification.
• Bench tested on actual hardware: We ran this cell through a full charge cycle and monitored the BMS handshake on power-up. The battery management system authenticated correctly, the charge IC accepted the cell without fault flags, and the device completed its power-on sequence normally.
• Post-installation self-test cycle: After fitting this battery, let the AccuScreen complete its full power-on self-test without interruption. The BMS runs a verification routine at startup — cutting power during this sequence triggers a false battery fault that stays latched until the next clean reboot.

AccuScreen not completing boot sequence on a new battery

The AccuScreen runs a BMS learn cycle during its first few charge-discharge passes. On a fresh cell, the charge IC applies a conservative voltage ceiling until the BMS has profiled the new chemistry — this can cause the boot sequence to stall or produce a battery fault on the first one or two power cycles. This is not a defective cell. Run one complete charge to full termination, then discharge through normal clinical use, and repeat once. After that cycle, the BMS calibration stabilises and the boot sequence completes cleanly.

Charge indicator not reaching 100% on the first charge

On the first charge of a new Li-ion cell, the AccuScreen's charge controller applies a reduced current ceiling while it characterises the cell's internal resistance. The display may plateau at 95–99% and hold there rather than reaching full termination. This is the charge IC acting conservatively on an uncharacterised cell — not a capacity or compatibility fault. Leave the device on charge until the indicator clears to 100%; this typically completes by the second charge cycle once the controller has a baseline resistance reading for the new cell.