About this replacement
Kaufel 850.0057 — 6V Ni-CD Replacement Battery (BGN2500-5DWP-A800EC)
This is a 6V, 3000mAh nickel-cadmium replacement cell for the Kaufel 850.0057 emergency lighting unit. It restores backup illumination function when the original cell has degraded or failed. Voltage, capacity, and connector match the OEM specification for this fitting.
- Kaufel 850.0057 fitting compatibility: The 850.0057 uses a dedicated charge controller calibrated to a 6V Ni-CD float voltage. Swapping in a different chemistry or voltage will cause the controller to over- or under-charge the cell, shortening its service life and potentially triggering a persistent fault LED.
- Bench tested on actual hardware: We cycled this cell through a full charge and discharge on a 6V Ni-CD compatible test rig. The BMS accepted charge without fault, held voltage above the cutoff threshold throughout the discharge phase, and showed no memory-effect artefacts from factory storage.
- Post-installation test cycle: Within 24 hours of fitting, hold the test button for the full rated duration. This confirms the cell accepts load under live conditions and lets the charge controller register the new cell's capacity before any scheduled compliance inspection.
Emergency light failing its duration test after battery replacement
A freshly installed Ni-CD cell shipped from storage has not yet been fully conditioned. The cell enters its first test cycle at partial capacity, so the light may cut out before the rated duration is reached. This is not a fault with the cell — it needs one full charge-discharge cycle to reach its rated 3000mAh. Allow a minimum 24-hour charge before running a formal compliance test.
Charge indicator staying red after new battery installation
When a replacement cell arrives from extended storage, its resting voltage may sit outside the float acceptance window the Kaufel charge controller expects. The controller reads this as an abnormal cell and holds a fault or charging state, keeping the indicator red. Leave the fitting on mains power for a full 24-hour charge cycle — the controller will accept the cell once the voltage climbs into the expected range. If the indicator stays red beyond 48 hours, measure the cell terminal voltage directly; it should be reading above 5.8V by that point.