Lithium battery Charger for 18650 and 21700 batteries.
Amazon.com: Charmast Portable Charger, Small 10000 Quick Charge Battery Pack, USB C Power Bank Fast Charging Mini Portable Battery Charger for iPhone, Samsung, Pixel, LG, TCL, OnePlus, Motorola, More Phones : Cell
Battery Tender 12 Volt Battery Charger 022-0199-DLWH