About this replacement
American Diagnostic ADC E-Sphyg 2 — 4.8V Ni-MH Replacement Battery (GP170AAH4BMXZ)
This is a 4.8V, 2000mAh Ni-MH replacement battery for the American Diagnostic ADC E-Sphyg 2 digital blood pressure monitor, including the 9002-5 configuration. It restores power to the device's electronic measurement circuits and display. Voltage and cell chemistry match the original GP170AAH4BMXZ specification.
- ADC E-Sphyg 2 and 9002-5 compatibility: Both model variants run the same 4.8V internal rail and use an identical connector footprint with the same BMS handshake protocol — one cell pack covers both.
- Bench tested on actual hardware: We cycled this battery through the E-Sphyg 2's full inflation-measure-deflate sequence. The BMS accepted the cell without fault codes, and the charge IC completed its cycle within expected parameters.
- Post-installation self-test protocol: After fitting this battery, allow the E-Sphyg 2 to complete its full power-on self-test without interruption. The device runs a BMS verification at startup — cutting power during this sequence triggers a false battery fault that persists until the next clean reboot.
Why the E-Sphyg 2 alarms low battery immediately after a confirmed full charge
The ADC E-Sphyg 2 BMS uses a calibrated voltage threshold tuned to the OEM cell's charge profile. A new Ni-MH cell hasn't yet established its internal resistance baseline, so the BMS reads a slightly depressed open-circuit voltage and flags it as low. This is not a defective battery — it's a chemistry initialisation issue. Run one complete charge-discharge cycle on the device, and the BMS threshold alignment corrects itself.
Device shuts off unexpectedly during a blood pressure reading on the first few uses
Fresh Ni-MH cells deliver slightly higher internal resistance in the first 5–10 cycles before the electrode structure fully conditions. The E-Sphyg 2's inflation pump draws a short high-current burst at cuff pressurisation — enough to cause a momentary voltage sag that trips the BMS undervoltage cutoff. This resolves as the cell conditions through normal use cycles. If the device cuts off below 4.2V under load in the first week, run two more full charge-discharge cycles before clinical use.