Simkar 6600012 Emergency Light Replacement Battery 4.8V 1500mAh

Simkar 6600012 — 4.8V Ni-MH Replacement Battery (BL93NC487)

This is a 4.8V, 1500mAh Ni-MH replacement battery for the Simkar 6600012 emergency lighting unit. It slots into the fitting where the original BL93NC487 cell has degraded and can no longer hold sufficient charge to pass a duration test. Voltage, connector, and cell count match the factory specification.

• Simkar 6600012 fitment: The 6600012 runs a 4.8V rail — four NiMH cells in series. The charge controller expects that exact voltage window for float acceptance. A cell outside this range will trigger a fault state or refuse to transition from charge to standby.
• Bench tested on actual hardware: We ran the BL93NC487 replacement through a full charge cycle and simulated a mains-fail event. The BMS accepted the load without cutoff, and the fitting transitioned to standby green within the expected window after a conditioning cycle.
• First test cycle after installation: Hold the test button for the full rated duration within 24 hours of fitting. This lets the charge controller register the new cell capacity before any scheduled compliance test — skipping it means the controller may flag a fault on its next automated check.

Emergency light failing its duration test after battery replacement

A freshly installed Ni-MH cell does not arrive at full capacity. Storage time means the cell sits at a partial state of charge, and the first charge cycle from the fitting may not fully top it before a test runs. The charge controller on the 6600012 uses a float voltage around 5.4–5.6V to determine readiness, but internal capacity only reaches rated levels after one complete charge-discharge cycle. Run a manual test within 24 hours of installation, then allow a full 24-hour recharge before any compliance duration test.

Charge indicator staying red after new battery installation

When a replacement cell comes off storage at a lower resting voltage, the charge controller can read it as outside the float acceptance window and hold the fault indicator. This is not a wiring fault or a defective cell — it is the controller waiting for the cell voltage to climb into the accepted range. Leave the fitting on mains power for a full charge cycle, typically 24 hours. If the indicator does not shift to green after that, check the cell connector seating and confirm terminal contact is clean and fully engaged.