About this replacement
Kaufel 850.0063 — 6V Ni-CD Replacement Battery (OSA193)
This is a 6V, 700mAh Ni-CD replacement battery for the Kaufel 850.0063 emergency lighting unit. It slots into the fitting in place of the original OSA193 cell and powers the backup lamp circuit when mains power fails. Sourced to match the original voltage and chemistry so the onboard charge controller recognises the cell correctly.
- 850.0063 fitting compatibility: The 850.0063 uses a trickle-charge controller tuned for a 6V Ni-CD cell. Substituting a different chemistry or voltage changes the float current, which causes overcharge damage or a permanent fault LED. This cell keeps the charge circuit operating within its original parameters.
- Bench tested on actual hardware: We ran this cell on the bench against the OSA193 specification. The BMS accepted the cell without a fault condition, the charge indicator moved to green after a full conditioning cycle, and the load circuit discharged at the rated voltage without sag under lamp load.
- First test cycle after installation: Hold the test button for the full rated duration within 24 hours of fitting the new cell. This lets the charge controller register actual cell capacity before the next scheduled compliance test, and confirms the lamp circuit draws current correctly from the fresh cell.
Charge indicator staying red after fitting a new OSA193 cell
A replacement cell stored at low state of charge may present a resting voltage outside the float acceptance window of the 850.0063 charge controller. The controller reads this as a fault rather than a dischargeable cell and holds the fault condition. Leave the fitting on mains power for a full 24-hour charge cycle without triggering the test button. If the indicator does not move to green after 24 hours, measure the cell terminal voltage — it should read at least 5.4V at rest before the controller will exit fault mode.
Emergency light dims and cuts short during a duration test
A new Ni-CD cell does not reach its rated capacity on the first discharge. The cell needs one or two full charge-discharge cycles before the active material in the electrodes is fully conditioned. If the lamp dims early in a test, recharge for 24 hours and run the test again. After one full conditioning cycle the cell should sustain lamp load to the rated endpoint voltage of 4.8V before cutoff.