It would work, but not well. These cells are the older NiCd chemistry which only had about a third of the capacity of the NiMH cells you currently use. So your light would only run for a third as long. I didn't even know that NiCd cells were still being made. Poor capacity, some charging cycle issues, and very bad environmentally if not disposed of properly - so they've been replaced by NiMH and various Li chemistries.