15W DC 3V 21V Electronic Test Load resistor USB Interface Battery Discharge Capacity Tester with Fan Adjustable Current Module|Battery Testers| – AliExpress Bought Jovan Stosic April 10, 2022 Source: 15W DC 3V 21V Electronic Test Load resistor USB Interface Battery Discharge Capacity Tester with Fan Adjustable Current Module|Battery Testers| – AliExpress