Legrand U21LED 70LM Compatible Battery 2.4V 800mAh Ni-CD

Legrand U21LED 70LM / BAES / BAEH Series — 2.4V Ni-Cd Replacement Battery (062524)

This is a 2.4V, 800mAh Ni-Cd rechargeable cell for Legrand emergency luminaires including the U21LED 70LM, BAES, BAEH, and BAEH ECO1 series. It powers the lamp circuit during mains failure, holding the fitting in compliance for duration testing. Physical dimensions are 50.50 × 28.60 × 14.50mm — verify against your existing cell before ordering.

• U21LED 70LM and BAES/BAEH platform fit: These fittings share a common 2.4V charge rail and two-cell Ni-Cd format. The connector pinout and cell orientation are consistent across the listed models, so one cell SKU covers the range without modification.
• Bench tested on actual hardware: We cycled this cell through charge acceptance and load discharge on a 2.4V emergency lighting controller. The BMS registered charge within the float voltage window and the cell held load through a full simulated duration draw without voltage collapse.
• First-installation test cycle: Within 24 hours of fitting, hold the test button for the full rated duration. This confirms the new cell accepts load under real conditions and lets the charge controller register cell capacity before the next scheduled compliance test.

Emergency light failing its duration test after battery replacement

A freshly installed Ni-Cd cell does not arrive at full capacity. Storage depletes the cell to a resting voltage that the charge controller accepts for float charging, but the cell has not yet gone through a full charge-discharge conditioning cycle. Duration tests run immediately after installation will often fall short of the rated period. Run at least one full manual test cycle — charge the fitting for 24 hours, then trigger a full discharge via the test button — before recording the result against a compliance schedule.

Charge indicator staying red after new cell installation

Some Legrand controllers set a fault flag when cell voltage drops below the float acceptance threshold during storage. The controller reads the incoming cell as potentially defective and holds the fault LED rather than entering charge mode. This is not a wiring fault. Leave the fitting powered for 12–24 hours — the trickle current will bring the resting cell voltage above 2.2V, at which point the controller clears the flag and the LED shifts to green.