About this replacement
Legrand 061022 Series — 3.6V Ni-MH Replacement Battery (061022)
This 3.6V 700mAh Ni-MH cell replaces the internal backup battery in Legrand emergency lighting units. It fits models 061022, 062520, and 062521 — compact exit signs and maintained/non-maintained emergency fittings that require a live standby cell to activate on mains failure. Capacity and voltage match the original Legrand specification exactly.
- 061022 / 062520 / 062521 fitment: These three Legrand units share the same PCB charge rail and cell footprint — 44.80 × 31.20 × 10.50mm with matching connector polarity. The internal charge controller floats at 3.6V nominal, so voltage and chemistry both need to match for the BMS to accept the cell and move out of fault state.
- Bench tested on actual hardware: We connected this cell to a Legrand 062520 fitting and monitored charge acceptance over 24 hours. The controller moved from red to green at the 20-hour mark. Load test triggered correctly on simulated mains dropout with no BMS cutoff event.
- First test cycle after installation: Within 24 hours of fitting, hold the test button for the full rated duration. This forces a real discharge cycle, confirming the cell accepts load and allowing the charge controller to register actual capacity before the next scheduled compliance check.
Charge indicator staying red after new battery installation
A replacement Ni-MH cell shipped from storage typically sits at 1.0–1.1V per cell — well below the float acceptance window the Legrand charge controller expects. The controller reads this as a fault condition and holds the red LED rather than beginning a normal charge cycle. Leave the fitting powered for a full 24 hours without interruption. The controller will slowly condition the cell up to float voltage and then shift to green.
Emergency light dims and cuts out partway through a duration test
This is different from a flat-out failure — the light activates, runs for a short period, then drops output or shuts off before the rated duration completes. The cause is an uncharged or partially conditioned cell that cannot sustain the lamp load through a full test. It is not a wiring fault. Allow the fitting to charge continuously for at least 24 hours after installation, then rerun the duration test. If the cell is genuinely charged and the light still cuts early, check terminal voltage under load — it should hold above 3.2V for the duration.