But if you're old NiCad charger dies, you might find yourself wondering if one of the new 18V One+ battery chargers would work in its stead. Unfortunately, that doesn't seem to be the case.

from the standard versions to the high-performance models (the Rapid Charger or any of the RYOBI 18V ONE+ chargers, however, can't charge NiCad batteries). Besides the ONE+ battery slot ...