Viasys Healthcare Nicolet Vascular OM11616 7.2V Replacement Battery

Viasys Healthcare Nicolet Vascular Versalab SE — 7.2V Ni-MH Replacement Battery (OM11616)

This is a 7.2V, 2100mAh Ni-MH battery for the Viasys Healthcare Nicolet Vascular Versalab SE and related Versalab portable vascular diagnostic units. It replaces OEM part numbers OM11616, B11616, and BT-U029. Fit models include the Versalab LE, APM, and APM2.

• Versalab platform compatibility: The SE, LE, APM, and APM2 share the same 7.2V battery bay and connector pinout. The BMS in each unit communicates with the cell pack over the same handshake protocol, so one battery form factor covers the full Versalab line.
• Bench tested on actual hardware: We cycled this battery through charge and load on the bench. The BMS accepted the cell, cleared initial impedance flags after the first full charge, and the charge indicator stepped through normally without throwing a fault condition.
• Power-on self-test after installation: After fitting this battery, let the Versalab complete its full startup sequence without interruption. The device runs a BMS verification check at power-on. Cutting power mid-sequence triggers a false battery fault that persists until the next clean reboot — not a cell defect.

Device not completing boot sequence on a new Versalab battery

The Versalab BMS checks cell voltage and internal resistance at startup before clearing the device for clinical operation. A new Ni-MH cell arrives partially discharged from storage and may sit just below the BMS acceptance threshold on first boot. This causes the unit to halt mid-sequence or loop back to a battery fault screen. Run one full charge cycle on the new cell before attempting to boot the device — the BMS re-evaluates the cell on the next power-on attempt.

Charge indicator stalls below 100% on first Versalab charge

The Versalab charger circuit applies a conservative delta-peak cutoff algorithm that is calibrated to an aged OEM cell's charge curve. A fresh Ni-MH cell has a flatter voltage rise during the initial charge, so the charger terminates early before the cell is fully topped up. The fix is to allow a second charge cycle immediately after the first completes. By the second cycle, the cell's charge signature aligns with the charger's detection window and the indicator reaches full at approximately 8.4V pack terminal voltage.