Biohit Proline 6V Ni-MH Compatible Battery 150mAh

Biohit Proline / ePET Series — 6V Ni-MH Replacement Battery (711002 / 110302)

This 6V, 150mAh Ni-MH cell replaces the internal battery in Biohit Proline and ePET electronic pipettes. It also fits the ST4 and ST4 SG platforms. The battery powers the dispensing motor, display, and onboard electronics during liquid handling operations.

• Proline, ePET, ST4, and ST4 SG compatibility: These models share the same 6V battery rail, physical form factor (30.00 × 24.72 × 14.26 mm), and connector pinout. The BMS expects Ni-MH chemistry for charge termination logic — substituting a Li-ion cell of similar voltage will trip a permanent fault on these platforms.
• Bench tested on actual hardware: We cycled this cell through the Proline charge circuit and confirmed the BMS reached full charge termination using delta-V detection, which Ni-MH chargers in this platform rely on. Charge acceptance was consistent across five consecutive cycles.
• Power-on self-test after installation: After fitting this battery, let the pipette complete its full startup self-test without pressing any keys or interrupting power. The BMS runs a verification pass at boot — cutting it short logs a false battery fault that will persist until the next clean reboot cycle.

Why the Proline pipette alarms low battery immediately after a confirmed full charge

The Proline's charge controller uses a stored capacity baseline to judge battery state. A fresh replacement cell has no history in that register, so the BMS compares its output against the OEM cell's learned profile and flags it as low. This is not a fault with the cell — it is a calibration gap. Run one complete charge-to-discharge-to-charge cycle before using the pipette in a clinical workflow. After that cycle, the BMS updates its threshold and the alarm clears.

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

Ni-MH cells self-discharge during storage. If the cell voltage has dropped below the BMS recovery threshold — typically around 5.4V for a 6V pack — the pipette's protection circuit blocks startup entirely rather than risk operating on an undervoltage supply. Connect the pipette to its charger and leave it on charge for a full cycle without attempting to power it on. Once the cell climbs back above the recovery threshold, the BMS will allow normal startup and the boot sequence will complete.