DOTLUX FLASHwall 7.4V Compatible Battery 4967 1500mAh

DOTLUX FLASHwall / FLASHground — 7.4V Li-ion Replacement Battery (4967)

This is a 7.4V 1500mAh Li-ion replacement battery for the DOTLUX FLASHwall and FLASHground emergency lighting units. It powers the backup illumination circuit during mains failure, keeping egress lighting active when the grid drops. Capacity is 1500mAh (11.1Wh), matching the original cell specification for Part No 4967.

• FLASHwall and FLASHground compatibility: Both fittings use the same 7.4V two-cell Li-ion pack with the same physical footprint (52 × 36.70 × 20mm) and connector orientation. The charge controller in each unit operates on the same float voltage, so one cell works across both models without modification.
• Bench tested on actual hardware: We cycled this cell through a simulated mains-fail event and monitored BMS behaviour at full load. The protection circuit held discharge cutoff at approximately 6.0V and recovered cleanly once charging resumed — no latching fault state triggered.
• First-cycle commissioning on emergency fittings: Within 24 hours of installation, hold the test button for the full rated duration. This confirms the cell accepts load and lets the charge controller register the new pack before your next scheduled compliance test — skipping this step can cause a false fail on duration testing.

Emergency light failing its duration test after battery replacement

A freshly installed Li-ion cell often ships at a partial state of charge — typically 40–60% — due to storage protocols that protect cell chemistry during transit. When the fitting runs a duration test before the cell has completed a full charge cycle, it depletes faster than rated capacity allows. The charge controller needs at least one complete charge-to-discharge cycle to recalibrate its capacity register. Allow 24 hours of mains-connected charging before running any compliance duration test on a new cell.

Charge indicator staying red after new battery installation

The FLASHwall charge controller uses a float acceptance window — typically 7.2V to 8.4V — to confirm the pack is viable before switching to charge mode. A cell that has sat in storage for several months may present a resting voltage below this window, causing the controller to flag a fault rather than begin charging. Leave the fitting connected to mains for two to four hours; most controllers will retry the charge cycle automatically once the cell voltage recovers past the acceptance threshold. If the red LED persists beyond four hours, measure cell voltage directly — a reading below 6.0V indicates a deeply discharged cell that the controller will not recover.