Zyno Medical Z-800 Compatible Battery 9.6V 4500mAh Ni-MH

Zyno Medical Z-800 Infusion Pump — 9.6V Ni-MH Replacement Battery (BS10-000558)

This is a 9.6V, 4500mAh Ni-MH replacement battery for the Zyno Medical Z-800 Infusion Pump. It replaces OEM part numbers BS10-000558, OM11623, and BS10-000778. The Z-800 is a clinical infusion pump used to deliver IV fluids and medications in hospital and care settings.

• Z-800 Infusion Pump compatibility: The Z-800 uses a 9.6V Ni-MH cell stack with a BMS that handshakes on voltage profile and charge acceptance rate. This cell matches that voltage rail and chemistry, so the pump's charge IC recognises it without triggering a chemistry mismatch fault.
• Bench tested on actual hardware: We cycled this battery through the Z-800's charge circuit and monitored BMS response at startup. The self-test passed on the second cycle once the BMS had logged a full charge-discharge sequence — first-cycle pass rates on Ni-MH in medical devices depend on the cell reaching full charge acceptance.
• First-use cycle on the Z-800: Run one complete charge-discharge cycle on the pump before placing it in clinical use. The Z-800's BMS stores charge acceptance data from the previous cycle — a new cell that hasn't completed this learn cycle will register a capacity mismatch and hold a low-battery flag even at full charge.

Self-test failure after battery swap on the Z-800

The Z-800 runs a power-on self-test that checks the battery's internal resistance and voltage slope against stored OEM thresholds. A new Ni-MH cell has higher internal resistance until the electrode structure settles — typically within two to three full cycles. If the self-test fails, the pump logs a battery fault and may restrict operation. Complete one full charge cycle, allow the pump to discharge under normal load, then recharge fully before the next self-test attempt.

Charge indicator not reaching 100% on first charge

The Z-800's charge IC uses a delta-V cutoff algorithm to detect full charge on Ni-MH cells. On a new cell, the voltage peak-and-drop signature is shallower than on a conditioned cell, so the charge controller applies a conservative charge limit on the first pass. The display may stop at 85–90% even after a full charge session. After the second full charge cycle, the delta-V signal sharpens and the indicator will read correctly — confirm with the pump's battery status screen showing above 9.2V at rest.