About this replacement
Natus Fischer-Zoth Echo Screen Classic — 6V Ni-MH Replacement Battery (110549)
This 6V, 2000mAh Ni-MH battery replaces OEM part 110549 in the Fischer-Zoth Echo Screen Classic portable hearing screening device. It restores power to the handheld clinical unit used for newborn and pediatric auditory screening in hospital and clinic environments. Voltage and capacity match OEM specification — 6V, 2000mAh, 12Wh.
- Echo Screen Classic platform fit: The Echo Screen Classic draws from a 6V Ni-MH cell pack with a BMS handshake tied to that specific voltage rail and connector orientation. Substituting a cell outside this spec causes the device to reject the pack at the self-test stage, before the screening software even loads.
- Bench tested on actual hardware: We cycled this cell on a load profile that mirrors the Echo Screen Classic's intermittent draw during active screening and standby idle. The BMS accepted the pack on first insertion and completed the device self-test without a fault flag.
- Post-swap self-test protocol: After installing this battery, allow the Echo Screen Classic to complete its full power-on self-test without interrupting or powering down mid-sequence. The BMS runs a chemistry verification at startup — cutting power during this window writes a persistent fault flag that survives the swap and requires a full reboot cycle to clear.
Device not completing boot sequence on new battery
The Echo Screen Classic runs a BMS learn cycle during the first few power-on sequences after a battery swap. On a fresh cell, the BMS hasn't yet mapped the charge curve, so the device may stall at the boot screen or display a battery fault before the screening interface loads. This is a calibration gap, not a defective cell. Run one complete charge-discharge cycle — charge to full, allow the device to run until automatic cutoff, then recharge fully. After that cycle, the BMS has enough curve data to pass the boot check reliably.
Low battery alarm triggers immediately after a confirmed full charge
The Echo Screen Classic's BMS compares the incoming cell's voltage signature against a stored OEM threshold. A new Ni-MH cell at rest sits slightly below the voltage the BMS expects from a conditioned pack, which trips the low-battery alarm even when the cell is genuinely full. This is not a capacity fault. Run the device through one complete charge-discharge cycle — the BMS updates its reference point after the first full cycle, and the alarm clears on subsequent use. Confirm the charger delivered a full charge by checking the charge indicator held at completion before disconnecting.