Vislone Digital Display Battery Capacity Internal Resistance Tester Digital Lithium Battery Power Detector Module 18650 Battery Test Meter Dual Type-C Interface: Amazon.com: Industrial & Scientific
18650 Battery Voltage Tester and Internal Resistance Tester for Battery Automatic Sorting
1-4pcs 18650 3.7V 3000mAh internal resistance small lithium battery stable performance wide application range VTC6-flat head - AliExpress