Thorn Voyager Star LA 2 Compatible Battery 2.4V 4500mAh Ni-MH

Thorn Voyager Star LA 2 SBS CON3 75 — 2.4V Ni-MH Replacement Battery (59009424)

This is a 2.4V, 4500mAh Ni-MH cell for the Thorn Voyager Star LA 2 SBS CON3 75 emergency lighting fixture. It replaces OEM part 59009424 when the original cell degrades and the unit can no longer hold its rated emergency duration. Capacity and dimensions match the original so the cell seats correctly inside the fitting.

• Star LA 2 SBS CON3 75 compatibility: This fitting uses a 2.4V NiMH cell on a simple trickle-charge controller — no BMS handshake required. The charge circuit accepts any cell within its voltage window, so physical dimensions and terminal orientation are the critical factors. At 92.70 × 36.60 × 18.70mm, this cell matches the original footprint.
• Bench tested on actual hardware: We ran this cell through a full charge and discharge cycle on a NiMH test rig at 2.4V. The cell accepted charge cleanly, reached rated capacity, and held terminal voltage within the expected range under sustained load. No anomalous heat rise at the charge termination point.
• Post-install conditioning for compliance testing: Run a full manual test cycle within 24 hours of fitting the new cell. Hold the test button for the unit's rated duration. This confirms the cell accepts load and lets the charge controller register the new cell before your next scheduled compliance inspection.

Charge indicator staying red after new cell installation

A freshly shipped NiMH cell arrives partially discharged — typically between 1.1V and 1.2V per cell. The trickle-charge controller in the Star LA 2 fitting expects incoming cell voltage within a narrow float acceptance window. If the cell voltage sits too low on insertion, the controller may flag a fault state rather than entering normal charge mode. Leave the fitting on mains power for a full 24-hour charge before checking the indicator — the controller should transition to green once the cell climbs into its acceptance band, around 1.35–1.40V per cell under float.

Emergency light dims and cuts early during the duration test

If the light dims noticeably within the test period on the first activation after replacement, the cell has not yet reached rated capacity. NiMH cells fresh from storage need at least one full charge-discharge cycle to hit their rated 4500mAh. This is not a fault with the cell or the fitting. Allow 24 hours on charge, then run the full test cycle again — terminal voltage should stay above 2.0V under load through the rated duration.