The discussion revolves around the experimental process of discharging AAA batteries, specifically focusing on measuring capacity at a constant current of 1A. Participants explore methods for achieving this discharge rate, the implications of discharge current on battery capacity, and the challenges of measuring the electromotive force (emf) during the discharge process.
Participants express differing views on the importance of measuring open circuit emf versus load voltage during battery discharge. There is no consensus on the best approach to measuring emf while discharging the battery, and the implications of discharge current on capacity remain a point of contention.
Limitations include the dependence on battery type (alkaline vs. NiMH) and the potential variability in internal resistance as the battery discharges. The discussion also highlights the need for careful measurement techniques to ensure accurate data collection.
... pick a low capacity battery.How would I be able to discharge the battery at a 1A current so that I don't have to wait for a long period of time?
DrZoidberg said:You realize that the discharge current affects the capacity?
If it's discharged at just a few mA, a AAA alkaline battery can deliver around 1200mAh. However at a current of 400mA the capacity is only 400mAh and at 1A it will be even much less than that. That's why alkaline batteries are really bad for digital cameras.
http://data.energizer.com/PDFs/l92.pdf
Simon Bridge said:What do you mean by "true" emf?
I think you'll find that the open circuit emf is generally not of much interest. (Though maybe you have a niche application where it is.) You should check that you are required to plot the no-load voltage, as that would be unusual. Most common would be a plot of load voltage vs. time while the load current is maintained at some specified constant level.johnsmith12345 said:Well I need it so that I can get enough data about the open circuit emf to plot a discharge curve.