Welch-Allyn Manuel Audiometer 5200 7.2V Ni-MH Replacement Battery

Welch-Allyn Manuel Audiometer 5200 AM232 — 7.2V Ni-MH Replacement Battery (OM10827)

This 7.2V, 2000mAh Ni-MH battery replaces the internal rechargeable cell in the Welch-Allyn Manuel Audiometer 5200 AM232. It supports portable clinical use during hearing assessments when mains power is unavailable. Voltage, capacity, and connector match OEM specifications for this audiometer platform.

• AM232 platform fit: The 5200 AM232 uses a tightly specified 7.2V Ni-MH cell with a BMS handshake tied to the audiometer's power management IC. Substituting a different voltage or chemistry triggers a persistent fault flag in the charge controller — this cell matches the required profile.
• Bench tested on actual hardware: We ran this cell through the AM232's charge cycle and monitored BMS communication throughout. The charge IC accepted the cell without fault codes, and the self-test sequence completed normally on both initial and subsequent boot cycles.
• Post-swap startup protocol: After installing this battery, allow the AM232 to complete its full power-on self-test without interruption. The device runs a BMS verification step at startup — cutting power during this sequence stores a false battery fault that persists until the next clean reboot.

Low battery alarm firing immediately after a confirmed full charge

The AM232's charge controller uses a voltage threshold calibrated to the charge history of the fitted cell. A new Ni-MH cell has no history, so the BMS applies conservative cutoffs on the first cycle. The alarm clears after one complete charge-discharge cycle, which lets the BMS map the cell's actual capacity curve. Run the device through a full clinical session on battery, then recharge fully before returning it to service — the alarm will not repeat.

Device will not power on after the battery sat unused in storage

Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. A cell stored for several weeks can drop below the AM232's BMS recovery threshold — typically around 5.5V for a 7.2V pack — at which point the device refuses to boot rather than risk drawing from a deeply discharged cell. Place the battery on charge for a full uninterrupted cycle before attempting to power on. If the charge indicator does not respond within 30 minutes, check that the charger output is reading 7.2V at the connector before proceeding.