Bacharach B11967 3.6V Ni-MH Compatible Battery 2000mAh

Bacharach Medigas PM 3010 N2O Monitor — 3.6V Ni-MH Replacement Battery (B11967)

This 3.6V, 2000mAh Ni-MH battery replaces part number B11967 in the Bacharach Medigas PM 3010 nitrous oxide monitor. The PM 3010 is a portable gas detection instrument used in operating theatres, dental suites, and laboratories to measure N2O concentrations in breathing systems and anaesthetic gas mixtures. Voltage and chemistry match the original pack exactly.

• PM 3010 platform fit: The PM 3010 uses a single-cell Ni-MH configuration at 3.6V nominal to keep the electrochemical sensor circuit and display within a stable operating window. The B11967 form factor — 49.50 × 28.20 × 25.30mm — seats directly in the battery compartment without modification.
• Bench tested on actual hardware: We cycled this pack through the PM 3010's charge and discharge stages and confirmed the BMS accepted the cell without throwing a battery fault code. Cell voltage held within the instrument's acceptance threshold across repeated charge cycles.
• Post-install calibration requirement: After fitting this battery, run a full calibration cycle through the PM 3010's instrument menu before field deployment. The monitor maps battery state during calibration, and skipping this step causes premature low-battery warnings during the first active monitoring session.

BMS lockout after the PM 3010 sat unused in a carry case for months

Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. A PM 3010 stored for several months can arrive at the charger with a cell voltage so low the instrument's charge circuit refuses to initiate — it reads the pack as faulty rather than deeply discharged. The B11967 replacement pack ships with a partial charge, but if the original pack was left in the instrument during storage, the charger may still lock out. To recover, place the instrument on charge for at least 30 minutes before powering on — most chargers apply a trickle current at voltages down to approximately 1.0V per cell before switching to full charge mode.

PM 3010 display showing inconsistent battery percentage after a new pack is installed

The PM 3010 uses a voltage-threshold indicator rather than a coulomb-counting circuit to estimate charge level. When a new cell with a different internal resistance profile replaces an aged pack, the indicator reads voltage instead of true charge and can display erratic percentages — jumping from 80% to 20% across a single session. This is a calibration artefact, not a cell defect. Run two full charge-discharge cycles and then perform the instrument's calibration routine; the voltage thresholds will recalibrate to the new cell's characteristics and stabilise the display.