About this replacement
Legrand 061883 — 3.6V Ni-CD Replacement Battery (H95999)
This is a 3.6V, 2000mAh Ni-CD cell for the Legrand 061883 emergency lighting unit. It slots into the fitting and connects to the onboard charge controller that keeps the cell at float charge during normal mains operation. When mains power fails, this cell drives the lamp circuit to keep exit routes illuminated.
- 061883 fitting compatibility: The 061883 uses a single-cell Ni-CD format at 3.6V with a specific pin spacing and lead length. The charge controller in this fitting expects a Ni-CD delta-V charge curve — a Li-ion or NiMH substitution will either trip the controller or overcharge. Match the chemistry and voltage exactly.
- Bench tested on actual hardware: We ran this cell through a simulated mains-fail cycle on a 061883-class fitting. The BMS accepted the cell at float charge within 15 minutes of installation, and the lamp circuit activated cleanly on mains interrupt. No false fault LEDs appeared after the test cycle completed.
- First installation test cycle: Hold the test button for the full rated duration within 24 hours of fitting this cell. A new cell shipped from storage may be partially discharged. Running one full test cycle lets the charge controller register actual cell capacity before any scheduled compliance inspection.
Charge indicator staying red after fitting the new cell
The 061883 charge controller uses cell voltage to determine whether to switch from bulk charge to float. A cell that has sat in a warehouse will arrive below the float acceptance threshold — typically under 3.3V. The controller reads this as a fault or holds in bulk charge mode, keeping the indicator red. Leave the fitting powered for 12–24 hours without pressing the test button. Once the cell reaches approximately 3.6V under trickle charge, the indicator should move to green.
Emergency light dims partway through the duration test
This happens when the cell has not completed a full conditioning charge before the test is triggered. A partially charged Ni-CD cell delivers rated current for a short period, then voltage sags as the cell depletes faster than expected. It is not a sign of a faulty cell. Charge the fitting on mains for a full 24 hours, then re-run the duration test — the cell should sustain the lamp at consistent brightness through the complete cycle.