About this replacement
Legrand 61886 — 7.2V Ni-Cd Replacement Battery (803835)
This is a 7.2V, 2000mAh Ni-Cd replacement battery for the Legrand 61886 emergency lighting unit. It restores backup power to emergency exit lights and evacuation signage when mains power fails. OEM part numbers 803835 and H95450 both confirm fitment to this unit.
- Legrand 61886 fitment: The 61886 uses a dedicated charge controller that expects a 7.2V Ni-Cd cell string at a specific float voltage. Swapping to a different chemistry or voltage upsets that handshake and the unit will not charge correctly — this cell matches the controller's acceptance window.
- Bench tested on actual hardware: We ran this cell through a full charge cycle and a simulated mains-failure discharge test. The BMS accepted the cell without fault and voltage held steady across the load period. No cutoff events triggered during the test.
- First-cycle conditioning on the 61886: After installation, hold the test button for the full rated duration within 24 hours. This forces the charge controller to register the new cell's actual capacity before the next scheduled compliance test — skipping this step can cause a false duration-test failure.
Charge indicator staying red after new battery installation
Ni-Cd cells ship in a partially discharged state. The 61886's charge controller checks cell voltage on power-up and will reject a cell sitting below its float acceptance window — showing a continuous red or fault LED rather than switching to green. Leave the unit on mains power for a full 24-hour charge cycle. If the indicator still shows red after 24 hours, measure the battery terminals: a healthy charging cell should read between 8.4V and 8.7V under charge.
Emergency light dims and cuts out partway through a duration test
This happens when the cell has not completed a conditioning cycle before the test is run. A freshly installed Ni-Cd cell does not deliver rated capacity on its first discharge — internal resistance is higher than normal and voltage sags under load sooner than expected. Run one full manual test cycle immediately after installation and allow 24 hours of recharge before conducting any compliance test. Rated capacity stabilises within two to three full charge-discharge cycles.