Lithonia ELB1210N Compatible Battery 1.2V 2100mAh Ni-MH

Lithonia ELB1210N Series — 1.2V Ni-MH Replacement Battery (ELB-1210N)

This is a 1.2V 2100mAh Ni-MH cell for Lithonia emergency lighting units. It fits the ELB1210N, ELB1P201N, ELB1P2901N, and related fixtures that use the LQMSW3R12277ELW cell format. The battery powers the backup lighting circuit during mains failure and sustains the charge controller's float cycle between tests.

• ELB1210N and ELB1P201N series compatibility: These fixtures share the same 1.2V single-cell charging circuit and mechanical bay dimensions. The connector and cell footprint — 43.70 × 20.10 × 17.14mm — match across all listed models, so the charge controller's float voltage and cutoff thresholds apply uniformly to this cell.
• Bench tested on actual hardware: We ran this cell through full charge and a load discharge on a compatible Lithonia fixture. The BMS accepted the cell without fault, the charge indicator transitioned from red to green within the expected window, and the cell held voltage above cutoff through the full rated cycle.
• First test cycle after installation: Within 24 hours of fitting the new cell, press and hold the test button for the full rated test duration. This lets the charge controller register actual cell capacity and resets its internal baseline before your next scheduled compliance test.

Why the charge indicator stays red after a new cell installation

Ni-MH cells lose charge during storage — a cell sitting in a warehouse for several months can drop well below the float acceptance window the Lithonia charge circuit expects. When the controller sees an incoming voltage outside that window, it holds the fault state and keeps the indicator red. The fix is to let the fixture charge uninterrupted for a full 24-hour cycle. After that conditioning period, the cell voltage climbs into the acceptance band and the controller clears the fault — indicator should shift to green once the cell reaches approximately 1.35–1.40V under float.

Emergency light dims and cuts short during a duration test

A new cell that hasn't completed its first full charge cycle will show rated voltage on the bench but sag under load within minutes of the test starting. The charge controller's low-voltage cutoff trips early because the cell hasn't yet reached full electrochemical conditioning. This is not a faulty cell — it's a cell that needs one complete charge-discharge cycle before it delivers rated capacity. Charge the unit for 24 hours, then run the full duration test; voltage under load should hold above 0.9V through the entire test window.