Sartorius Proline Electronic 6V Ni-MH Replacement Battery

Sartorius Proline Electronic / ePET — 6V Ni-MH Replacement Battery

This is a 6V 150mAh Ni-MH rechargeable battery for the Sartorius Proline Electronic and ePET portable laboratory balances. These scales are used in medical, pharmaceutical, and research environments where accurate sample measurement is critical. The replacement cell matches the original voltage and chemistry required by the onboard charge management circuit.

• Proline Electronic and ePET platform: Both models share the same internal battery bay dimensions and 6V Ni-MH charge circuit. The BMS on these balances expects Ni-MH chemistry — substituting a different chemistry triggers a charge fault that will not clear without a hardware reset.
• Bench tested on actual hardware: We ran charge-discharge cycles on this cell format and confirmed the BMS completes its learn cycle after the first full charge. On the first cycle, the charge IC applies a conservative current limit, so the indicator may not reach 100% until cycle two.
• Post-swap self-test protocol: After installing this battery, allow the Proline Electronic to complete its full power-on self-test without interruption. Cutting power during this sequence registers a false battery fault that persists through subsequent boots until the device performs a clean, uninterrupted startup.

Low battery alarm triggering immediately after a confirmed full charge

The Proline Electronic BMS compares cell voltage against a threshold calibrated to an aged OEM cell's charge curve. A new Ni-MH cell has a slightly different internal resistance profile, so the BMS may read the terminal voltage as below threshold even when the cell is fully charged. This is not a defective battery — it is the learn cycle not yet completed. Run one full charge-discharge cycle and the BMS recalibrates its reference. The alarm clears once the cell voltage holds above 5.4V under load during the self-test.

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

Ni-MH cells self-discharge during storage, typically losing charge at 1–3% per day depending on temperature. If the cell voltage drops below approximately 4.8V, the Sartorius charge IC enters a trickle pre-charge phase rather than a standard charge cycle. The balance will not power on during this phase. Leave the device connected to its charger for a minimum of two hours before attempting to power on — this allows the pre-charge current to bring the cell above the BMS recovery threshold.