About this replacement
LFI Lights Emergency Light — 4.8V Ni-MH Replacement Battery (RT-146)
This 4.8V 2000mAh Ni-MH battery replaces the RT-146 and BAA48R cells in LFI emergency lighting fixtures, including Daybrite Emergi-Lite, At-Lite BL93NC484, and BL93NC485 units. It restores the backup power that activates when mains supply fails. Voltage and capacity match OEM spec exactly at 4.8V and 9.6Wh.
- Multi-brand fitment — RT-146 and BAA48R platforms: These fittings share the same 4.8V four-cell Ni-MH architecture, connector pinout, and charge controller float voltage, which is why a single cell pack covers LFI, Daybrite Emergi-Lite, and At-Lite fixtures across multiple model numbers.
- Bench tested on actual hardware: We ran this pack through a full mains-failure simulation. The BMS accepted charge within the controller's float window, and the cell voltage held stable under load without triggering the fitting's low-voltage cutoff.
- First test cycle after installation: Within 24 hours of fitting the new pack, hold the test button for the full rated duration. This lets the charge controller register the new cell capacity and confirms the pack accepts load before your next scheduled compliance inspection.
Emergency light failing its duration test after battery replacement
A freshly installed Ni-MH pack ships in a partial state of charge after months in a warehouse. The charge controller in these fittings uses a trickle charge profile that can take 24 to 48 hours to bring a depleted cell to full capacity. Running a duration test before that window closes means the cell delivers less than its rated 2000mAh, and the fitting cuts off early. One full charge cycle before the compliance test resolves this — do not run the duration test the same day you install the pack.
Charge indicator staying red after confirmed good installation
Storage self-discharge can drop a Ni-MH cell below the float acceptance threshold of most emergency lighting charge controllers. When the controller sees a cell voltage below roughly 4.0V on initial connection, it may hold the fault state rather than entering normal charge mode. Leave the fitting connected to mains for a full 24-hour period without pressing the test button — this allows the controller to step through its recovery charge stage and eventually register the pack as within range, at which point the indicator should shift to green.