PowerSonic OSA052 12V Emergency Light Replacement Battery 8000mAh

PowerSonic A35241 — 12V Ni-CD Replacement Battery (OSA052)

This is a 12V, 8000mAh nickel-cadmium replacement battery for the A35241 emergency lighting unit. It replaces OEM part OSA052 directly. The cell restores backup illumination capacity in fittings where the original cell has degraded or failed compliance testing.

• A35241 fitting compatibility: The A35241 charge controller runs a fixed trickle voltage matched to Ni-CD cell chemistry. Substituting a different chemistry disrupts the charge curve and will damage the fitting's charge circuit over time. This cell matches the original voltage profile and connector orientation.
• Bench tested on actual hardware: We ran this cell through a full charge cycle and load test. The BMS accepted charge without fault, held voltage under load without collapsing, and discharged cleanly to cutoff with no mid-test drop.
• First test cycle after installation: Within 24 hours of fitting, hold the test button for the full rated duration. This confirms the new cell accepts load and lets the charge controller register the new cell capacity before any scheduled compliance test runs against it.

Why the A35241 charge indicator stays red after fitting a new cell

Ni-CD cells sit at a depressed open-circuit voltage after storage — often below the float acceptance threshold the A35241 controller expects to see before switching to green. The controller reads the cell voltage on insertion and parks in a fault or charge state until the voltage climbs into the acceptance window. This is not a wiring fault. Leave the fitting powered for 12–24 hours and the indicator will shift to green once the cell reaches approximately 13.8V under trickle.

Emergency light dims and cuts short during a duration test

A new Ni-CD cell that has not completed one full conditioning cycle will not deliver rated capacity on first discharge. The cell delivers partial capacity, voltage sags early, and the fitting dims or cuts off before the rated duration is reached. This is a cell state issue, not a fitting fault. Charge the unit for a full 24 hours after installation, then run one complete test cycle — subsequent tests will reflect the rated 8000mAh capacity.