Measuring Lithium Ion Battery Internal Resistance (ESR) to quickly identify bad cells. - YouTube
LeTkingok 4 Line YR1035 Battery Internal Resistance Test Meter- High Precision/Battery Voltage Tester/Digital Battery Analyzer (Set A): Amazon.com: Electronics
How to make Battery Internal Resistance Meter with Arduino and Atmel ATtiny85 IC
How to make Battery Internal Resistance Meter with Arduino and Atmel ATtiny85 IC