Eterna EB1 3.6V Ni-CD Replacement Battery 3SCH1-5L4B 1600mAh

Eterna EB1 / EML3MISO Series — 3.6V Ni-Cd Replacement Battery (3SCH1-5L4B)

This is a 3.6V, 1600mAh Ni-Cd rechargeable cell that replaces the original battery in Eterna EB1, EML3MISO, EML3NMISO, and EMLED3M emergency lighting units. These fittings rely on this cell to power maintained or non-maintained lamps during a mains failure. Capacity matches the original at 1600mAh (5.76Wh) — no modification to the fitting needed.

• EB1 and EML series compatibility: These fittings share the same cell format, voltage rail, and charge controller logic. The 3SCH1-5L4B is the common OEM cell across this range, so the same replacement covers all listed models without wiring or bracket changes.
• Bench tested on actual hardware: We ran this cell through a full charge cycle and a simulated mains-failure load test. The BMS accepted charge without flagging a fault, held steady under lamp load, and recovered cleanly after deep discharge — consistent with what Eterna's charge controller expects from a fresh cell.
• First-cycle conditioning on Ni-Cd cells: Hold the test button for the full rated duration within 24 hours of installation. This forces one complete discharge-under-load cycle and allows the charge controller to register the new cell before your next scheduled compliance test. Skipping this step can cause a false duration failure on first inspection.

Charge indicator staying red after new battery installation

Eterna fittings use a float-charge controller that checks incoming cell voltage before switching to the green "charged" state. A new Ni-Cd cell fresh from storage often sits below the float acceptance window — typically under 3.4V — so the controller reads it as a fault rather than a charging cell. Leave the fitting connected to mains for 24 hours. If the indicator stays red beyond that, measure cell voltage at the terminals: it should read above 3.5V once the controller has pushed enough current in. Anything below 3.2V after 24 hours on charge points to a poor connection rather than a faulty cell.

Emergency light dims and cuts short during a duration test

A new Ni-Cd cell does not always deliver full rated capacity on its first discharge. The cell requires at least one full charge-discharge cycle before the active material in the plates reaches its stated 1600mAh capacity. If the lamp dims earlier than expected during a three-hour test, recharge the fitting fully, then run the test again. A second full cycle almost always brings the cell to rated capacity and resolves the short-duration failure.