Amazon.com: Battery Converter for Dewalt to Ryobi Battery Adapter with USB Port,Convert Dewalt 20V and Milwaukee 18V to Ryobi 18V Battery Power Tools Use,5V/2.1A USB Port for Phone Charger by POWHAZY (DM18RL) :
Ryobi 18-Volt Lithium + HP High Capacity 9.0 Ah Battery - - Amazon.com