About this replacement
Willing Wi201575 VTC — 3.6V Ni-CD Replacement Battery (300148-20)
This is a 3.6V, 2500mAh nickel-cadmium replacement battery for the Willing Wi201575 VTC emergency lighting unit. It replaces OEM part number 300148-20. The cell restores backup illumination capability to the fitting after the original battery has degraded past its serviceable threshold.
- Wi201575 VTC platform fit: The Wi201575 VTC charge controller is tuned to a specific float voltage window for Ni-CD chemistry at 3.6V. Swapping to a different chemistry or voltage alters the charge termination point, which trips the fault circuit. This cell matches the expected charge profile the controller monitors.
- Bench tested on actual hardware: We ran this cell through a full charge cycle and load test. The BMS accepted the cell within the standard float window. No false fault signals were observed during the conditioning cycle.
- First-cycle test requirement: Within 24 hours of installation, press and hold the test button for the full rated test duration. This confirms the cell accepts load current and lets the charge controller register the new cell before the next scheduled compliance inspection.
Emergency light failing its duration test after battery replacement
A freshly installed Ni-CD cell does not arrive at full capacity. Storage discharge means the cell may hold only 60–70% of rated capacity on day one. The charge controller needs a full uninterrupted charge cycle — typically 24 hours on trickle — before the cell reaches 2500mAh. Running a compliance duration test before that cycle completes will produce a short-duration result that does not reflect the cell's true capacity. Allow one full charge before logging any test result.
Charge indicator staying red after new battery installation
The charge controller on the Wi201575 VTC monitors incoming cell voltage to confirm the new cell is within its float acceptance window. A cell that has self-discharged deeply during storage may present a voltage low enough that the controller flags it as a fault rather than entering charge mode. Connect the fitting to mains and leave it for two to four hours — the cell voltage will rise passively to the point where the controller accepts it and transitions to charge mode. If the indicator remains red past four hours, measure the cell terminals with a multimeter and confirm voltage is climbing above 3.0V.