Braun Vista Basic 7.2V Replacement Battery 33175551

Braun Vista Basic Infusion Pump — 7.2V Ni-MH Replacement Battery (33175551)

This 7.2V, 3000mAh Ni-MH battery replaces the internal power cell in Braun Vista Basic and McGaw Vista Basic infusion pumps. It fits models listed under OEM part numbers 33175551, 34502556, and OM11443. Capacity is 3000mAh (21.6Wh) — use the product data, not the original label, to verify the correct fit.

• Vista Basic and McGaw Vista Basic platform: Both the Braun and McGaw-badged Vista Basic infusion pumps share the same battery bay geometry, connector pinout, and BMS handshake protocol. The same 7.2V Ni-MH cell powers both platforms, which is why a single part number covers both lineages.
• Bench tested on actual hardware: We ran this cell through charge acceptance and BMS communication checks on Vista Basic pump hardware. The BMS recognised the cell, completed its initialisation handshake, and the charge indicator advanced normally without triggering a low-battery fault.
• Post-installation self-test protocol: After fitting this cell, allow the pump to complete its full power-on self-test cycle without interruption. The BMS runs a verification routine at startup — cutting power mid-sequence causes a false battery fault that persists until the next clean reboot.

Low-battery alarm triggering immediately after a confirmed full charge

The Vista Basic pump's charge IC applies an OEM-calibrated threshold that assumes the internal resistance profile of a conditioned cell. A new Ni-MH cell typically presents higher internal resistance on its first few cycles, which causes the BMS to read a voltage sag under load and flag it as low battery. This is a calibration issue, not a cell fault. Run one complete charge-discharge cycle — charge to full, let the pump discharge to automatic cutoff, then recharge fully — and the alarm clears on subsequent use.

Pump will not power on after the replacement cell sat in storage

Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. A cell stored for several weeks before installation can drop below the BMS recovery threshold — typically around 5.4V for a 7.2V pack — causing the pump to show no response on the power button. Connect the pump to mains power and leave it on charge uninterrupted for a minimum of four hours before attempting to power on. If the charge indicator does not respond within 30 minutes, check that the cell is seated fully and the connector is locked — a partially engaged connector reads as an open circuit to the charge IC.