Maybe 2nd best $20 new accessory?? Turns any 18v ryobi battery into a usb power bank. This guys isn't getting any love but I think it's pretty neat too. : r/ryobi
RYOBI ONE+ 18V Lithium-Ion Portable Power Source P743 - The Home Depot
power tool battery as USB power bank Ryobi 18v lithium - YouTube
Ryobi Inverter - 18V Battery Powered - Her Tool Belt
Ryobi 18V ONE+ 2.0Ah Battery and Charger Kit RC18120-120
Fast Power Tool Battery Charger for Ryobi P108 P105 Li-ion Ni-CD Ni-MH Battery 12V-18V X9q8e - China Ryobi Battery Charger and Power Tool Battery Charger price | Made-in-China.com
RYOBI ONE+ 18V Lithium-Ion Portable Power Source with 2.0 Ah Battery and Charger P743-PSK005 - The Home Depot