Saft 804284N Emergency Light Replacement Battery 4.8V 2000mAh

Saft 804284N — 4.8V Ni-Cd Replacement Battery for Emergency Lighting

This is a 4.8V 2000mAh Ni-Cd replacement cell for the Saft 804284N emergency lighting unit. It fits directly into the existing battery compartment and powers the lamp circuit during mains failure. Capacity is 2000mAh (9.6Wh) — taken from the product data, not estimated.

• 804284N platform fit: The 804284N uses a fixed 4.8V Ni-Cd cell voltage to match the charge controller's float threshold. Swapping to a different voltage or chemistry trips the controller outside its acceptance window and prevents a full charge cycle from completing.
• Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on the bench. The BMS accepted charge without fault, held voltage under simulated load, and the charge indicator stepped from red to green within the expected window.
• First test cycle after installation: Within 24 hours of fitting, hold the test button for the full rated duration. This confirms the new cell accepts load and lets the charge controller register the new cell capacity before your next scheduled compliance inspection.

Emergency light failing its duration test after battery replacement

A freshly installed Ni-Cd cell has not yet completed a full conditioning cycle, so its usable capacity at the point of test can be well below the 2000mAh rating. The charge controller tops the cell up in float mode, but float alone does not run the cell through a deep charge-discharge sequence. One manual test cycle — a full load discharge followed by a full recharge — allows the cell plates to reach rated capacity. After that cycle, the fitting should pass a standard duration test at 4.8V under load.

Charge indicator staying red after confirmed good installation

If the cell has been in storage, its resting voltage can drift below the charge controller's float acceptance threshold — typically around 4.6V for a 4.8V Ni-Cd pack. The controller reads this as a fault condition rather than a low cell and holds the fault LED on. Leave the fitting connected to mains for at least 24 hours. The trickle current will raise cell voltage back into the acceptance window, and the indicator should step to green once the controller re-polls the cell voltage.