Powercell PCHA4/5-2-SR-LC Replacement Battery 2.4V 2100mAh

Powercell PCHA4/5-2-SR-LC — 2.4V Ni-MH Replacement Battery

This is a 2.4V, 2100mAh Ni-MH replacement battery for Powercell PCHA4/5-2-SR-LC emergency lighting fittings. It slots into commercial exit signs and emergency luminaires that rely on this cell format for backup illumination during mains failure. Capacity is 5.04Wh — sourced to match the original cell specification.

• PCHA4/5-2-SR-LC fitting compatibility: The PCHA4/5-2-SR-LC housing uses a dedicated cell format with a fixed connector orientation and 43.72 × 34.10 × 17.30mm footprint. Swapping to a different cell size or tab configuration will prevent the charge circuit from making contact correctly.
• Bench tested on actual hardware: We ran this cell through a simulated mains-failure discharge at rated load. The BMS accepted charge from the float circuit within the expected voltage window and held stable output through a full duration cycle without thermal event.
• First-cycle test procedure: Hold the test button for the full rated duration within 24 hours of installation. This allows the charge controller to register the new cell's capacity before any scheduled compliance test. Skipping this step is the most common cause of a failed duration test after a fresh installation.

Emergency light failing its duration test after battery replacement

A new Ni-MH cell ships in a partial state of charge — typically 30–50% — due to transit storage and self-discharge. The fitting's charge controller needs time to bring the cell up to full float voltage before the cell can deliver rated capacity under load. If a compliance duration test runs before that conditioning cycle completes, the light will cut out early. Allow a full 24-hour charge after installation, then run one manual test cycle before logging the unit as compliant.

Charge indicator staying red after new battery installation

Some PCHA-series fittings use a voltage threshold to switch the charge LED from red to green. A cell that has been in storage will sit below the float acceptance window — often under 2.2V — when first installed. The controller interprets this as a fault rather than a charging state. Leave the fitting on mains power for 12–24 hours; once the cell climbs above the float threshold (typically 2.8V for a 2.4V Ni-MH cell at end of charge), the indicator should switch to green automatically.