Resistance Meter, Battery Internal Resistance Voltmeter Resistance Tester with LCD Display, Battery Internal Resistance Meter Voltage Resistance Tester for Automobiles Electric Vehicles: Amazon.com: Tools & Home Improvement
LeTkingok 4 Line YR1035 Battery Internal Resistance Test Meter- High Precision/Battery Voltage Tester/Digital Battery Analyzer (Set A): Amazon.com: Electronics
Measuring Internal Resistance of Batteries - SparkFun Learn
How to check your LiPo battery pack's Internal resistance with Tenergy's 5-in-1 Cell meter - YouTube