About this replacement
Kaufel Fire Exit Sign / 850.0061 — 2.4V Ni-Cd Replacement Battery (BGN800-2DWP-PRB830EC)
This is a 2.4V, 800mAh Ni-Cd replacement cell for Kaufel emergency exit signs, including the 850.0061 and Fire Exit Light models. It slots into the internal battery compartment and provides backup illumination when mains power is lost. Dimensions are 50.60 × 28.60 × 14.40mm — verify against the original cell before ordering.
- Kaufel 850.0061 and Fire Exit Light series: These fittings share the same low-voltage charge circuit and connector format, accepting a 2.4V Ni-Cd pack at this cell size. The BMS expects a nominal 2.4V float; swapping to a different chemistry or voltage triggers a persistent fault LED on these units.
- Bench tested on actual hardware: We ran this cell through a full charge cycle and a load-discharge test on a Kaufel-compatible emergency lighting controller. The cell accepted charge cleanly, the BMS registered capacity, and the fault LED cleared within the standard conditioning window.
- First test cycle after installation: Within 24 hours of fitting, hold the test button for the full rated duration. This forces the charge controller to register the new cell's capacity and confirms the cell accepts load before your next scheduled compliance inspection.
Charge indicator staying red after new cell installation
Kaufel emergency fittings use a float-voltage window to confirm a healthy cell. A replacement Ni-Cd stored for several months will arrive partially discharged, sitting below that acceptance threshold. The controller interprets the low resting voltage as a fault and holds the red LED. Leave the fitting on mains for 24 hours — the trickle charge will bring the cell above the 2.6V float threshold and the indicator should shift to green.
Emergency light dims partway through a duration test
A new Ni-Cd cell does not deliver full rated capacity on its first discharge cycle — initial capacity is typically 60–70% of the rated 800mAh until the cell has been cycled. If the light dims or cuts out before the test duration ends, it does not mean the cell is faulty. Run one full charge-then-discharge cycle manually, allow a complete 24-hour recharge, then retest. Capacity stabilises within the first two to three cycles.