Amazon.com: JJXNDO 1-Pack DM18D Upgraded Version DCA1820 Converter for Dewalt 18V/20V & for Milwaukee M18 18V Battery to Work for Dewalt 18V Nicad&NiMh Battery Tool(Convert Lithium Battery to Nicad/Nimh Battery) : Tools
Snap on 18v Nicad to Dewalt Lithium Battery Adapter - Etsy