Does anyone know of an easy method of measuring the internal resistance of a battery?

 

A quick way to get a rough value is to measure the voltage of the battery at two different fixed loads.

Example:

http://chdk.setepontos.com/index.php?topic=2622.0

The formula is R = (V2-V1) / (P1/V1 - P2/V2), where R = collective resistance of batteries in series, P = consumed electrical power, V = measured battery voltage, (1) = LCD-on, (2) = LCD-off.

 

The DC Load document here explains a little about it and references a battery manufacturer's recommendations.

 

The DC Load document here explains a little about it and references a battery manufacturer's recommendations.

Great link. I have the BK8500 at work. Now I have to write a PIC serial driver for it to test UPS batteries.

 

Feedback and Suggestions Forum for providing feedback and suggestions about All About Circuits, including corrections to the e-book. This forum is not for getting help with technical questions.

This is not the forum you post this kind of thread, it should have been in the Electronic Chat forum. A moderator will be along shortly and move it I suspect.

The feedback is feedback on the board, not for your learning.

 

Great link. I have the BK8500 at work. Now I have to write a PIC serial driver for it to test UPS batteries.

If you use python, there's a python library on their software page that makes it easy to talk to the instrument if you have the RS-232 to TTL serial adapter that comes with the instrument.