How to generate discharge curve for batteries?

[wshyang]

Hi all,


I am actually wondering how those nice discharge curves for batteries are generated. At the moment, my impression of it is that they can be done with cool gadgets like the CBA IV or the iCharger, but is there any other cheaper and better way?

[Illum]

I don't think theres an easy way to do this, the circuit of a typical battery analyzer is somewhat similar to an LED driver. It provides a constant current drain [as opposed to a constant current feed] from the battery [as opposed to driving an LED]. To some extent a circuit that can simulate a constant current load can be used to test batteries to yield a greater degree of accuracy than via a resistor.
Try this, EDN 02.19.2009 Circuit provides constant-current load for testing batteries