About this replacement
Fagerhult C94-C228 / ED 90404 — 4.8V Ni-MH Replacement Battery (60AAAHTYMX)
This is a 4.8V, 600mAh Ni-MH replacement battery for Fagerhult emergency and decorative LED lighting fixtures. It fits the C94-C228 range, ED 90404, and Hertek ND223-229 series. Capacity is 2.88Wh — matching the original 60AAAHTYMX specification exactly.
- C94-C228 and Hertek ND223-229 compatibility: These models share the same 4.8V battery rail, connector footprint, and LED driver input range, which is why one cell pack covers the full range. The BMS on each fixture communicates with the cell over the same charge termination protocol.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a Fagerhult-compatible test fixture. The BMS accepted charge termination correctly and the LED driver held stable output voltage through discharge without early cutoff.
- First-cycle LED driver calibration: Run the light on medium brightness for the first full cycle. The LED driver calibrates its current output against the new cell's internal resistance — skipping this on a fresh Ni-MH pack can cause the driver to misread available capacity on the first few uses.
Why Fagerhult emergency fixtures report low battery before the cell is actually depleted
Fagerhult emergency fixtures monitor battery voltage at rest, not under load. A Ni-MH cell at 4.8V nominal sags noticeably under LED driver current draw, and the fixture's controller reads that sag as a low-battery condition. This happens most often with aged cells where internal resistance has risen. A new 60AAAHTYMX pack brings internal resistance back to spec, which reduces voltage sag and clears false low-battery readings during normal operation.
Light not reaching full brightness after battery swap
If the fixture dims out before reaching full brightness after a replacement, the battery likely shipped in a partially discharged state — Ni-MH cells self-discharge during storage. The LED driver requires a minimum input voltage of around 4.4V under load to sustain full output. Charge the battery fully in the fixture before the first use. After one complete charge cycle, full brightness should restore and hold consistently.