ESYLUX SLE 1634369 Replacement Battery 3.2V 1800mAh

ESYLUX SLE / SLF Series (ab 2022) — 3.2V LiFePO4 Replacement Battery (1634369)

This is a 3.2V, 1800mAh LiFePO4 cell rated at 5.76Wh, built to replace the original ESYLUX part number 1634369. It fits SLE and SLF emergency lighting units manufactured from 2022 onward. The LiFePO4 chemistry matches the charge profile the ESYLUX charge controller expects — substituting a different chemistry will cause charge faults.

• SLE and SLF (ab 2022) fit: ESYLUX revised the SLE and SLF charge circuitry from 2022 onward to accept LiFePO4 float voltage. Pre-2022 units used a different cell spec — check your fitting's production date label before ordering.
• Bench tested on actual hardware: We ran this cell through a full charge cycle and a simulated mains-failure load test. The BMS held voltage within the correct LiFePO4 discharge window and recovered cleanly to float charge on reconnection.
• First-install test cycle: Within 24 hours of fitting, hold the test button for the full rated duration. This lets the charge controller register the new cell capacity before the next scheduled compliance check — skipping it can cause an early false fail on a duration test.

Charge indicator staying red after new battery installation

LiFePO4 cells lose voltage during storage. If the cell ships below the charge controller's float acceptance window — typically under 2.8V per cell — the controller flags a fault rather than entering normal charge mode. Leave the fitting powered for 12 to 24 hours. Most ESYLUX charge circuits will trickle-charge the cell back into the acceptance window and then step up to normal charge automatically. If the red indicator persists beyond 24 hours, measure the cell terminal voltage — anything above 2.5V means the controller should recover it; below that, the cell has deep-discharged past recovery threshold.

Emergency light failing its duration test after battery replacement

A brand-new LiFePO4 cell does not deliver its full rated capacity on the very first discharge — it typically takes one complete charge-discharge cycle to reach the 1800mAh spec. Running a compliance duration test before that first cycle is complete will show a shorter-than-rated run and log a fail. Complete one full manual test cycle immediately after installation, then allow a full 24-hour recharge before the formal compliance test. After that conditioning cycle the cell should meet the rated 5.76Wh capacity the fitting's test log expects.