RKI 49-1609RK Replacement Battery 1.2V 1000mAh Ni-MH

RKI GX-2009 / GX-2012 / 49-1609RK — 1.2V Ni-MH Replacement Battery (BPH-2009)

This is a 1.2V, 1000mAh Ni-MH cell built to the BPH-2009 specification. It fits the RKI GX-2009, GX-2012, and 49-1609RK portable gas detectors. Voltage and form factor match the OEM cell exactly — 46.30 × 12.60 × 14.60mm.

• GX-2009, GX-2012, and 49-1609RK compatibility: These three instruments share the same battery bay geometry and 1.2V supply rail. The BPH-2009 cell interfaces directly with the internal charge circuit on each platform without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the GX-2009 platform. The instrument's BMS accepted the pack cleanly, with no charge rejection or error flags triggered during sensor initialisation.
• Calibration cycle before field deployment: After fitting this cell, run a full calibration cycle through the instrument menu before taking the unit into the field. The GX-series maps battery state during calibration — skipping this step causes premature low-battery warnings during the first active measurement session.

BMS lockout after the GX-2009 or GX-2012 sat unused in a carry case

Ni-MH cells self-discharge slowly over weeks. After extended storage, the cell voltage can drop below the threshold the instrument's charge circuit needs to initiate a charge cycle. When this happens, the charger sees a voltage too low to recognise and does nothing. Place the instrument on charge for at least 30 minutes before expecting the display to respond — the circuit needs to trickle current into the cell before it can begin a normal charge cycle. If there is still no response after 30 minutes, check that charge contact pins on the instrument are clean and making full contact.

Readings drifting or logging session resetting mid-measurement

This happens when sustained sensor load pulls cell voltage below the instrument's operating floor. The GX-series sensors draw a steady current across the measurement session, and an aged or partially charged Ni-MH cell sags under that load faster than the display indicator suggests. The instrument resets or drops readings to protect sensor circuitry. Charge the pack fully before any extended logging session, and confirm cell voltage sits at or above 1.2V before deployment.