Neptolux 175-8070 Compatible Battery 7.4V 700mAh Li-Polymer

Neptolux 175-8070 — 7.4V Li-Polymer Replacement Battery (2ICP/16/25/46 2S1P)

This 7.4V 700mAh lithium-polymer battery replaces the backup cell in the Neptolux 175-8070 emergency lighting unit and EVE B0408 fitting. It restores the unit's ability to switch to battery power during mains failure and sustain illumination for the rated test duration. Capacity is 700mAh (5.18Wh), matching the original specification.

• 175-8070 and EVE B0408 fitment: Both models use the same 2S1P lithium-polymer cell configuration at 7.4V nominal, with matching connector pinout and physical envelope of 45.30 × 25.00 × 16.50mm. The charge controller in each fitting expects the same float voltage and BMS handshake, so one cell covers both.
• Bench tested on actual hardware: We ran this cell through mains-cut simulation on the 175-8070 fitting. The BMS engaged cleanly on switchover, sustained the LED load without voltage sag tripping the low-cell cutoff, and accepted charge back to float without the controller flagging a fault.
• First test cycle after installation: Hold the test button for the full rated duration within 24 hours of fitting. This allows the charge controller to register the new cell capacity before any scheduled compliance test runs. Skipping this step can cause the unit to report a short-duration fail even with a fully functional cell.

Charge indicator staying red after new battery installation

The 175-8070 charge controller uses a voltage window to confirm a cell is present and accepting charge. A replacement cell that has sat in storage can arrive with a resting voltage below the controller's float acceptance threshold — typically under 7.0V — which the fitting reads as a missing or faulty cell. The controller holds the red fault state and will not transition to green until the cell voltage climbs into the acceptance window. Connect the fitting to mains and leave it undisturbed for up to four hours; once the cell voltage rises above approximately 7.2V, the controller will recognise it and switch to normal charge mode.

Emergency light dims and cuts out partway through a duration test

A new cell that has not completed a full conditioning charge will hit the BMS low-voltage cutoff before reaching the rated test duration. This happens because the cell's usable capacity on the first discharge is lower than its rated 700mAh until the electrodes have cycled fully. It is not a faulty cell. Charge the unit on mains for a minimum of 24 hours after installation, then repeat the manual test — the full duration should be available on the second test cycle.