7.2V Cas Medical NIBP 740 Replacement Battery 3800mAh

Cas Medical NIBP 740 / 940X Monitor — 7.2V Ni-MH Replacement Battery (03-08-0450)

This is a 7.2V 3800mAh Ni-MH replacement battery for the Cas Medical NIBP 740 non-invasive blood pressure monitor and related models. It fits the NIBP 730, NIBP 750, and 940X Monitor platforms that share the same battery bay and connector. OEM part numbers covered include 03-08-0450, 6036, 120336, OM11377, AS36036, BH-7238-RC5P, and B11377.

• NIBP 730 / 740 / 750 / 940X platform fit: These monitors share the same 7.2V Ni-MH battery format, connector pinout, and BMS communication protocol. A single cell revision covers all four because the charge IC and voltage thresholds are identical across the monitor line.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a NIBP-series monitor. The BMS accepted the new cell without fault, completed its verification sequence, and held voltage within spec through multiple automatic BP measurement cycles.
• Post-swap self-test protocol: After installing this battery, let the monitor complete its full power-on self-test without interruption. The BMS runs a verification routine at startup — cutting power during this sequence can trigger a persistent battery fault that will not clear until the unit is rebooted and allowed to finish the cycle.

Low battery alarm on the NIBP 740 immediately after a confirmed full charge

Ni-MH cells have a chemistry-specific charge signature. The NIBP monitor's charge IC uses a delta-V detection method tuned to the OEM cell's internal resistance profile. A new replacement cell has a slightly different charge curve for the first few cycles, which can cause the IC to report incomplete charging even when the cell is at full capacity. The fix is to run one complete charge-to-discharge cycle without interrupting the monitor mid-test. After one full cycle, the BMS recalibrates its capacity estimate and the alarm clears. If the alarm persists beyond three cycles, check that resting terminal voltage is at or above 7.2V before flagging a fault.

NIBP 740 will not power on after the battery sat unused in storage

Ni-MH cells self-discharge at roughly 1–3% per day at room temperature. A battery stored for several months can drop below the BMS minimum recovery threshold — typically around 5.4V for a 7.2V pack — at which point the monitor's protection circuit blocks power-on entirely. Connect the charger and leave it for a minimum of four hours before attempting to power on. If the charge indicator does not respond within the first 30 minutes, the cell voltage may be too low for the standard charge IC to engage — some chargers require the cell to be at or above 4.8V to begin a charge cycle.