DEWALT DW938 18VOLT CORDLESS SAWZALL can it use Lithium Batteries

As long as the voltage of the battery is the same as the tool, the tool won't mind if the power is coming from a NiCd or lithium battery. You do have to have a charger that works with lithium batteries to charge them up. Chargers that can charge lithium batteries can also charge NiCd and NMH batteies. NiCd chargers are not always programmed to detect when lithium batteries are full and may continue to charge them to the point of melting or starting on fire.