EluBat Swiss 275 602 Emergency Lighting Compatible Battery 2.4V 2000mAh Ni-MH

EluBat Swiss 275 602 / KRMT 23/43 — 2.4V Ni-MH Replacement Battery (671817.009)

This is a 2.4V, 2000mAh Ni-MH replacement cell for the EluBat Swiss 275 602, KRMT 23/43, and D-SC1800BTx2-MOLEX/5239 emergency lighting units. It carries OEM part number 671817.009 and fits the original MOLEX connector arrangement on these fittings. At 85.50 × 22.50 × 22.50mm, it swaps directly into the cell bay with no modification.

• Swiss 275 602, KRMT 23/43, D-SC1800BTx2 compatibility: All three models share the same 2.4V charge rail, MOLEX 5239-series connector, and charge controller float voltage. The BMS in each fitting accepts this cell's charge acceptance curve without reconfiguration.
• Bench tested on actual hardware: We ran this cell through a full charge cycle and simulated mains-failure test on a Swiss 275 602 unit. The charge controller reached float within the expected window and the BMS did not flag a cell fault during load discharge.
• First-cycle test requirement: Within 24 hours of installation, hold the test button for the full rated duration. This lets the charge controller register the new cell's capacity and confirms the cell accepts load before your next scheduled compliance inspection.

Charge indicator staying red after new battery installation

Emergency lighting charge controllers use a float acceptance window — typically 2.7V to 2.95V for a 2.4V Ni-MH cell. A cell that has sat in storage for several months will self-discharge below that window, so the controller sees the voltage as outside its expected range and holds the fault state. Leave the fitting connected to mains for a full 24-hour conditioning charge before drawing any conclusions. If the indicator is still red after 24 hours, measure across the cell terminals — you should see at least 2.6V.

Emergency light failing its duration test after battery replacement

A freshly installed Ni-MH cell rarely delivers full rated capacity on the first discharge — the chemistry needs one complete charge/discharge cycle to reach 2000mAh. If the fitting cuts out before the rated duration on its first post-replacement test, that is not a faulty cell; it is an unconditioned one. Run one full manual test cycle, allow a 24-hour recharge, then retest. The cell should hold load for the full rated duration on that second discharge.