Biohit Proline XL 4.8V Ni-MH Compatible Battery SA712898

Biohit Proline XL — 4.8V Ni-MH Replacement Battery (SA 712898)

This 4.8V 1500mAh Ni-MH battery replaces the OEM pack in the Biohit Proline XL electronic multichannel pipette. It fits the motorized pipetting unit used in laboratory and clinical liquid-handling workflows. Voltage, capacity, and connector match the original SA 712898 / 712898.01 specification.

• Proline XL platform fit: The Proline XL motor drive runs on a 4.8V Ni-MH rail. The BMS handshake requires a cell pack that matches the OEM charge-termination curve — substituting a different chemistry or voltage causes the charge IC to reject the pack entirely.
• Bench tested on actual hardware: We cycled this pack through the Proline XL charge circuit and confirmed the BMS accepted the cell on first connection, completed the delta-V cutoff correctly, and held steady voltage under the motor's aspiration and dispensing load pulses.
• Post-swap self-test protocol: After installing this battery, let the Proline XL complete its full power-on self-test without interruption. The device runs a BMS verification sequence at startup — cutting power during this window triggers a persistent battery fault that will not clear until the next complete reboot.

Why the Proline XL rejects a new Ni-MH pack on the first charge cycle

The Proline XL charge IC uses delta-V detection tuned to a conditioned Ni-MH cell. A fresh cell from storage has not yet established a consistent voltage-rise profile, so the IC can terminate early or flag a charge fault. This is not a defective battery — it is the charge algorithm applying a conservative threshold to an unconditioned cell. Running one complete charge-discharge cycle recalibrates the IC's baseline, and subsequent charges complete normally. If the fault persists beyond two full cycles, check that the battery contacts are seated flush against the terminal plate.

Proline XL shutting off mid-aspiration on a battery that passed the self-test

The motor draw during a full-volume aspiration stroke creates a brief current spike that stresses new cells harder than the self-test load does. In the first ten cycles, internal resistance in the fresh cell is slightly elevated, causing a momentary voltage sag that crosses the BMS undervoltage cutoff threshold. The device shuts off to protect the motor driver — not because the battery is depleted. The fix is to complete at least ten partial-load charge-discharge cycles before using the pipette at maximum aspiration volume. After conditioning, the cell's internal resistance drops and the sag stays above the 4.2V cutoff floor.