ERC LFE 03B Emergency Light Replacement Battery 3.6V 4000mAh

ERC LFE 03B / LFE 05B Series — 3.6V Ni-CD Replacement Battery (098017/960)

This is a 3.6V, 4000mAh nickel-cadmium replacement cell for ERC emergency lighting units including the LFE 03B, LFE 05B, LFE 05S, and COMBITRONIC system. It slots into the fitting in place of the original ERC cell (OEM references 098017/960 and 803169). Voltage and capacity match the original spec exactly — no modification needed to the charge circuit.

• LFE 03B, LFE 05B, LFE 05S, and COMBITRONIC compatibility: All four units share the same 3.6V trickle-charge circuit and use the same physical cell format (221 × 37.5 × 33.5mm). The charge controller in each fitting expects a Ni-CD cell at this voltage — swapping chemistry or capacity would push the cell outside the charge acceptance window and cause a persistent fault LED.
• Bench tested on actual hardware: We ran this cell through a full charge cycle and load test using a controlled discharge rig. The cell held voltage above the 3.0V cutoff for the rated duration and the BMS registered a healthy charge state on reconnection.
• Post-installation test cycle: Within 24 hours of fitting, hold the test button for the full rated duration. This confirms the cell accepts load under real conditions and allows the charge controller to register the new cell capacity before your next scheduled compliance inspection.

Charge indicator staying red after new battery installation

A Ni-CD cell coming out of long-term storage often sits at a lower resting voltage than the fitting's float acceptance window expects. The charge controller reads this as a fault rather than a depleted cell. Leave the fitting powered for 24–48 hours and the trickle charger will bring the cell voltage up into the acceptance range. If the indicator remains red past 48 hours, check the cell terminal connection and confirm contact resistance is below 0.5Ω at the tab joint.

Emergency light failing its duration test after battery replacement

A freshly installed Ni-CD cell does not deliver rated capacity on its first discharge — the cell needs at least one full charge-discharge cycle to reach the 4000mAh figure. If the unit cuts out before the test duration completes, run one full conditioning cycle: charge for 24 hours, then trigger the test button and allow a complete discharge. Recharge for another 24 hours before the official compliance test. Rated capacity should be present from the second cycle onward.