About this replacement
DOTLUX LIGHTBARexit — 3.2V LiFePO4 Replacement Battery (5432)
This is a 3.2V 3000mAh LiFePO4 cell for the DOTLUX LIGHTBARexit emergency exit light (Part No 5432). It replaces the internal backup cell that powers the unit during a mains failure. The cell measures 66.30 × 29.60 × 26.40mm and must be matched exactly — even a few millimetres variance causes fitment problems inside the housing.
- LIGHTBARexit platform fit: The LIGHTBARexit charge controller runs a fixed float voltage tuned to LiFePO4's 3.2V nominal. Swapping in a different chemistry — even at the same nominal voltage — throws the float acceptance window off and triggers a permanent fault LED.
- Bench tested on actual hardware: We cycled this cell through a full simulated mains-failure activation and measured the BMS cutoff behaviour under LED load. The cell held above the controller's low-voltage threshold for the full rated test duration without dropping into protection mode.
- First test cycle after installation: Run a manual test within 24 hours of fitting by holding the test button for the full rated duration. This lets the charge controller register the new cell's capacity and resets the compliance clock before your next scheduled inspection.
Emergency light failing its duration test after battery replacement
A freshly installed LiFePO4 cell ships in a partial state of charge — typically between 30% and 60%. If the fitting runs a scheduled duration test before the cell has completed a full charge cycle, the cell voltage drops below the controller's cutoff threshold early and the unit shuts off mid-test. The fix is straightforward: leave the fitting on mains power for at least 24 hours after installation before triggering any test. After one full charge, the cell reaches rated capacity and will sustain the load for the correct duration.
Charge indicator staying red after new battery installation
The LIGHTBARexit charge controller checks cell voltage against a float acceptance window on power-up. A cell that has sat in storage can measure slightly below 3.0V, which puts it outside that window and holds the charge LED red. Connect mains power and wait — the controller will trickle the cell up from its storage voltage. Once the cell rises above approximately 3.05V, the controller shifts to normal charge mode and the LED moves to green. Do not assume a fault until at least two hours have passed on mains power.