Lithonia ELB1P201NB Replacement Battery 1.2V 3000mAh

Lithonia ELB1P201NB / 1009S00-MZ / ELB0320 / OSA212 — 1.2V Ni-MH Replacement Battery

This is a 1.2V, 3000mAh (3.6Wh) Ni-MH cell for Lithonia emergency lighting fixtures. It fits the ELB1P201NB, 1009S00-MZ, ELB0320, and OSA212 units — exit signs and backup lighting heads that switch to battery power the moment mains voltage drops. Swapping this cell restores the fixture's ability to illuminate during a power outage and brings it back into compliance with scheduled duration test requirements.

• ELB1P201NB / OSA212 platform fit: These four models share a common 1.2V single-cell charge circuit, identical connector orientation, and matching physical envelope. The charge controller floats the cell at a fixed voltage, so cell geometry and chemistry must match exactly — this cell meets both.
• Bench tested on actual hardware: We ran this cell through a full charge cycle on an ELB1P201NB fixture, monitored the charge controller's transition from bulk to float, then triggered a simulated mains failure. The BMS accepted the cell without fault codes and the load circuit activated cleanly at cutover.
• First-cycle conditioning on emergency fixtures: Within 24 hours of installation, hold the test button for the full rated test duration. This forces the new cell through one complete load cycle, lets the charge controller register actual cell capacity, and resets the internal fault timer before your next scheduled compliance inspection.

Emergency light failing its duration test after battery replacement

A freshly installed Ni-MH cell ships in a partially discharged state — typically between 30% and 60% of rated capacity. The charge controller in these Lithonia fixtures uses a simple trickle-charge circuit that can take 24 to 48 hours to bring a new cell to full charge. If a duration test runs before that window closes, the cell will exhaust early and the fixture logs a fail. Install the cell, let the fixture charge undisturbed for at least 24 hours, then run the manual test. That sequence resolves the vast majority of post-replacement duration failures.

Charge indicator staying red after new battery installation

Storage discharge can leave a replacement cell below the float acceptance threshold of the charge controller — on these fixtures, that lower limit sits around 1.0V per cell. When the controller sees an incoming voltage outside its acceptance window, it holds the fault LED red and delays bulk charging. Leave the fixture on mains power for four to six hours without triggering a test; the trickle circuit will bring the cell voltage up into the acceptance band and the LED will transition to green. If the indicator stays red past six hours, check the cell's resting voltage with a multimeter — it should read at least 1.1V to confirm the cell is accepting charge.