About this replacement
Schuch 8020 / 8021 / Licht 2627 — 6V Ni-CD Replacement Battery (35-319B0519)
This is a 6V 2000mAh nickel-cadmium cell for Schuch emergency lighting fixtures in the 8020, 8021, and Licht 2627 series. It replaces OEM part 35-319B0519 and EK209001 0033. The cell fits directly into the existing battery compartment and connects to the on-board charge controller.
- 8020, 8021, and Licht 2627 compatibility: All three fixtures share the same 6V charging rail, the same cell footprint (112.50 × 47.20 × 22.50mm), and the same float charge threshold. One cell covers all three units without wiring changes.
- Bench tested on actual hardware: We ran this cell through a full simulated mains-failure cycle. The charge controller accepted the cell without fault, the BMS held voltage through the full discharge phase, and the charge LED transitioned to green within the expected window.
- 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 lets the charge controller register the new cell capacity before the next scheduled compliance inspection.
Emergency light failing its duration test after battery replacement
A freshly installed Ni-CD cell does not ship at full capacity. Storage self-discharge and cell conditioning mean the first test cycle often ends short of the rated duration. The charge controller needs at least one full charge-discharge cycle to calibrate to the new cell. Allow 24 hours on charge before running any compliance duration test. After that first full cycle, the cell should reach its rated 2000mAh (12Wh) capacity and hold voltage to 5.4V at end of discharge.
Charge indicator staying red after new cell installation
After months in storage, the cell resting voltage may sit outside the charge controller's float acceptance window. The controller interprets this as a fault rather than a low cell and holds the red LED. Connect the fitting to mains and leave it undisturbed for two to four hours — the controller typically re-enters normal charge mode once the cell voltage rises above 5.8V. If the LED stays red past four hours, check the cell connector seating and confirm polarity before suspecting the controller itself.