About this replacement
DOTLUX EXITflip 8H — 3.7V Li-ion Replacement Battery (5527)
This 3.7V, 3350mAh Li-ion cell replaces the original backup battery in the DOTLUX EXITflip 8H emergency lighting unit (Part No 5527 / 5528). It also fits the EXITflip 3H Cinema and panel-mount variants 5508-060360 and 5509-060360. Restoring this cell brings the fitting back to full mains-failure backup capability.
- EXITflip series compatibility: The 8H and 3H Cinema share the same single-cell 3.7V architecture and charge controller circuit. Both fittings use the same battery bay dimensions (68.00 × 18.50 × 18.50mm) and connector pinout, so one cell covers the full range listed above.
- Bench tested on actual hardware: We ran this cell through a full charge cycle on the EXITflip charge board and confirmed the BMS accepted the cell at the correct float voltage. The charge controller advanced from red to green within the expected charge window and the mains-failure relay triggered correctly on test.
- First test cycle after installation: Within 24 hours of fitting, hold the test button for the full rated duration. This lets the charge controller register the new cell's actual capacity before your next scheduled compliance inspection — skipping this step can cause the fitting to log a shorter backup duration than the cell can actually deliver.
Charge indicator staying red after fitting the new cell
A replacement cell shipped from storage typically rests at 3.4–3.5V — just below the EXITflip charge controller's float acceptance window. The controller sees that voltage as outside normal range and holds the red fault indicator rather than beginning the charge cycle. Leave the fitting on mains power undisturbed for two to four hours. Once the cell voltage climbs past approximately 3.6V, the controller re-enters normal charge mode and the indicator advances to green.
Emergency light dims and cuts short during a duration test
This happens when the fitting is tested before the new cell has completed its first full charge. A partially charged 3350mAh cell delivers noticeably less usable capacity under the constant LED load, so the light dims or the fitting trips its low-voltage cutoff before the rated duration is reached. The fix is straightforward: allow a full 24-hour charge on mains power before running any duration test. After that conditioning cycle, cell output stabilises at the full 12.4Wh and the fitting will complete its rated test duration without dimming.