Siemens Microscan 6459 Replacement Battery 2.4V 1500mAh

Siemens Microscan Turbidity Meter — 2.4V Ni-MH Replacement Battery (6459 / AAXARTL02 / B11744)

This is a 2.4V, 1500mAh Ni-MH replacement battery for the Siemens Microscan Turbidity Meter. The Microscan is a clinical laboratory instrument that measures particle concentration in fluid samples using optical detection. It is used in medical diagnostics settings where consistent, uninterrupted power directly affects measurement accuracy.

• Microscan Turbidity Meter fit: The Microscan draws a steady, low-current load during optical measurement cycles. This cell matches the voltage rail and physical form factor — 98.70 × 16.00 × 14.50mm — required by the original battery bay. OEM part numbers 6459, AAXARTL02, and B11744 all cross-reference to this specification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a calibrated fixture. The BMS accepted the cell without fault codes, and the charge IC reached target voltage without tripping thermal cutoff. Capacity came in at rated specification across test cycles.
• Power-on self-test handling: After fitting this battery, allow the Microscan to complete its full power-on self-test without interruption. The device runs a BMS verification sequence at startup — cutting power mid-sequence triggers a false battery fault that will persist until a complete reboot clears the register.

Why the Microscan reports a battery fault on the first few cycles after a cell swap

The Microscan's BMS stores a charge profile for the installed cell. When a new cell goes in, the BMS has no history and applies a conservative threshold during its self-test check. This can trigger a battery fault flag even when the new cell is fully charged. Running one complete charge-discharge cycle gives the BMS enough data to recalibrate its threshold to the new cell's actual capacity. After that first cycle, the fault flag clears and the device operates normally.

Charge indicator not reaching 100% on initial charge after installation

On the first charge, the Microscan's charge IC applies a reduced current limit when it detects an unrecognised cell — a safety measure common in medical-grade charge controllers. The indicator stalls below 100% because the IC is waiting for the cell voltage to stabilise before authorising the final top-up stage. This is not a fault with the cell. Let the charge cycle run to natural termination without disconnecting — the IC will step up to full charge once the cell voltage holds steady above 2.3V.