About this replacement
Huntleigh SC750 Monitor — 12V Ni-MH Replacement Battery (110786)
This is a 12V 4500mAh Ni-MH replacement battery for the Huntleigh SC750 portable fetal monitor. It fits the SC750 directly, using OEM part numbers 110786, 55483, 88890097, and EE090232. The SC750 is used in obstetric settings to track fetal heart rate and uterine contractions, so battery integrity matters every time the device is deployed.
- SC750 platform fit: The SC750 uses a fixed 12V Ni-MH pack with a specific connector and BMS handshake tied to Huntleigh's charge management circuit. Swapping to a different chemistry or voltage rail causes the charger to reject the pack or misread state-of-charge entirely.
- Bench tested on actual hardware: We cycled this pack through Huntleigh's charge profile and confirmed the BMS accepted the cell voltage curve without triggering a fault state. Capacity read within expected range at the end of the first full charge-discharge cycle.
- SC750 startup sequence care: After installing this battery, let the SC750 complete its full power-on self-test without interruption. The device runs a BMS verification at startup — cutting power mid-sequence plants a false battery fault that will persist until the next clean reboot.
Why the SC750 rejects a new battery during its self-test
The SC750's charge IC applies a conservative acceptance window calibrated to a conditioned OEM cell. A fresh replacement cell starts with a resting voltage that sits slightly outside this window, which the self-test reads as a fault. This is not a defective battery — it is the BMS protecting against an unverified chemistry. Running one complete charge-discharge cycle conditions the cell voltage curve to match what the charge IC expects. After that cycle, the self-test passes cleanly on every subsequent startup.
Charge indicator stalls below 100% on first charge
On the first charge, the SC750's charge management circuit applies a reduced current limit to an unrecognised cell. This causes the charge indicator to plateau between 85% and 95% and stop climbing. The cell is not defective — the charge IC is holding back until it confirms the internal resistance profile of the new pack. Allow the charge cycle to terminate naturally without interrupting it. Once the device completes that first full charge, subsequent cycles will reach 100% and hold.