About this replacement
Philips HP4745 ECG — 3.6V Ni-MH Replacement Battery (B10298)
This 3.6V, 1800mAh Ni-MH battery replaces part numbers B10298, AS10298, and OM10298 in the Philips HP4745 portable electrocardiograph. It fits the HP4745 ECG series used for cordless cardiac monitoring and cardiograph recording in clinical settings. Voltage and capacity match OEM specifications exactly.
- HP4745 ECG series fit: The HP4745 platform runs a 3.6V single-cell Ni-MH architecture with a fixed connector and BMS handshake tied to cell chemistry. Any cell outside that voltage rail or chemistry flag causes the BMS to reject the pack outright, so matching both is non-negotiable on this device.
- Bench tested on actual hardware: We cycled this cell through the HP4745 power-on sequence and confirmed the BMS handshake completes without fault codes. The charge IC accepted the cell on the first insertion. Load draw during a full ECG acquisition run stayed within the cell's continuous discharge rating throughout testing.
- Post-installation self-test protocol: After fitting this battery, let the HP4745 complete its full power-on self-test cycle without interrupting it. Medical-grade BMS firmware runs a chemistry verification at startup. Cutting power mid-sequence logs a false battery fault that persists until the device completes a full reboot from rest.
Why the HP4745 alarms low battery immediately after a confirmed full charge
The HP4745 BMS sets its low-battery threshold against a learned capacity baseline calibrated to the OEM cell. A new replacement cell has not yet established that baseline. The BMS reads an unfamiliar charge curve on the first cycle and flags it as a fault rather than accepting the full-charge state. Run one complete charge-to-discharge cycle without interruption, and the BMS recalibrates its threshold to the new cell's actual profile.
HP4745 failing to power on after the battery sat in storage
Ni-MH cells self-discharge at roughly 20–30% per month in storage. If the cell voltage drops below the BMS recovery threshold — typically around 3.0V on a 3.6V pack — the firmware will not initiate a boot sequence. The device appears completely dead even though the hardware is fine. Connect the HP4745 to mains power and leave it on charge for a minimum of four hours before attempting to power on, allowing the charge IC to bring the cell back above the BMS wake-up threshold.