Review of 18 Volt to 20 Volt Battery Adapters for Dewalt 18 Volt Drills and other power tools. - YouTube
Amazon.com: JJXNDO 2-Pack 18V to 20V Adapter DCA1820 for Dewalt 20V/18V Lithium ion Battery with USB Port, Convert 20V Battery DCB204 DCB206 to 18V NiCad NiMh Battery Tool : Tools & Home
DEWALT 20V MAX Lithium-Ion Battery Adapter for 18V Tools DCA1820 - The Home Depot