About this replacement
CONTEC HMS7500 — 7.4V Li-ion Replacement Battery (2.3.02.00200)
This 7.4V 5200mAh Li-ion battery replaces OEM part 2.3.02.00200 in the CONTEC HMS7500 portable patient monitor. The HMS7500 is a clinical and home healthcare device that measures SpO2, blood pressure, and heart rate. This replacement matches the original voltage, capacity, and connector configuration for the HMS7500 platform.
- HMS7500 platform fit: The HMS7500 uses a closed BMS handshake that validates cell voltage and internal resistance at startup. This battery meets those thresholds — the monitor completes its power-on self-test without triggering a battery fault flag.
- Bench tested on actual hardware: We cycled this cell through the HMS7500's charge IC and monitored BMS communication. The battery accepted a full charge, held voltage under the device's combined sensor load, and passed the monitor's internal battery validation routine.
- Post-swap self-test procedure: After installing this battery, allow the HMS7500 to complete its full power-on self-test without interruption. The BMS runs a verification sequence at boot — cutting power mid-cycle writes a false battery fault to memory that persists until the next clean full reboot.
Why the HMS7500 alarms low battery immediately after a confirmed full charge
The HMS7500's BMS compares the new cell's internal resistance profile against stored OEM parameters at first boot. A fresh cell that hasn't completed one full charge-discharge cycle hasn't yet settled to its rated resistance values, so the BMS flags a low battery condition even when the cell is at full capacity. This is a calibration gap, not a defective battery. Run one complete charge-discharge cycle on the device before clinical use — the BMS recalibrates on the second boot and the alarm clears.
HMS7500 will not power on after battery arrived from storage
Li-ion cells self-discharge during shipping and warehousing. If the cell voltage has dropped below approximately 2.5V per cell (5.0V pack total), the HMS7500's BMS enters deep-discharge lockout and the device shows no response — no boot screen, no alarm. Connect the monitor to mains power and leave it on charge for a minimum of two hours before attempting to power on. The charge IC applies a slow pre-charge trickle at low voltage to recover the cell, then resumes normal charging once the pack clears 6.0V.