About this replacement
Weighing Baby Baby One WUNDER — 7.2V Ni-MH Replacement Battery (E-1566)
This is a 7.2V, 2000mAh Ni-MH replacement battery for the Weighing Baby Baby One WUNDER infant scale and the bedscale Baby ONE ABILANX. OEM part numbers E-1566, HHR210AAB, and 88889009 all cross-reference to this cell configuration. It restores power to the medical-grade pediatric scale used in clinical settings to record newborn and infant weight.
- Baby One WUNDER and ABILANX compatibility: Both the Baby One WUNDER and bedscale Baby ONE ABILANX share the same 7.2V battery rail, connector pinout, and BMS handshake protocol, which is why one cell pack covers all three listed fit models.
- Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on a compatible scale and confirmed the BMS accepted the new pack without fault codes. The charge IC applied a conservative initial current limit on the first cycle, which is normal for a fresh Ni-MH cell.
- Post-swap self-test protocol: After installing this battery, let the scale complete its full power-on self-test without interruption. Medical scales run a BMS verification sequence at startup — cutting power mid-sequence triggers a false battery fault flag that persists until the next clean reboot cycle.
Why the Baby One WUNDER alarms low battery after a confirmed full charge
The scale's BMS uses a voltage threshold calibrated to the discharge curve of a conditioned OEM cell. A new, uncycled Ni-MH cell has a slightly flatter initial voltage response that the BMS can misread as low capacity. This is not a fault with the cell — it clears after one complete charge-discharge cycle. Run the scale until the low-battery indicator trips naturally, then charge fully to 7.2V before returning it to clinical use.
Scale will not power on after the battery sat in storage
Ni-MH cells self-discharge to roughly 1.0V per cell during extended storage. At that level, the BMS recovery threshold on this scale blocks startup to prevent damage from a deeply discharged pack. Place the battery on a compatible external Ni-MH charger first and bring it to at least 7.0V before reinserting. Once above threshold, the scale will boot normally and accept a standard charge cycle.