measuring internal resistance of a battery.

[bongkk]

Can a capacitor ESR meter be used to measure the internal resistance of a battery?

 

[barath_87]

Hey I think if you connect a resistor(Rs) across the battery and measure the voltage(Vs) drop across the resistor.

Current From battery I = Vs/Rs


Battery Voltage (Vbat)

Vbat = Vs + I*Rint (Internal resistance of the battery) and solve for Rint.

Iam not sure whats the application and the accuracy . But this measurement should be reasonable if you can get an accurate Rs.

I am not sure if you can use an ESR meter to do that..


I am open for corrections.

 

[FvM]

Depends on your definition of internal resistance and the features of your LCR meter.

If not specified otherwise, internal resistance would be understood as a DC parameter as discussed by barath_87.
It should be determined by measuring a voltage drop in loaded condition. But a battery also has a frequency dependent
impedance. It can be measured with a LCR meter (if it can handle the DC voltage) or a similar instrument.