This project is cool because it features the re-use of found objects in electronics; things you might have laying around the garage, or at a yard sale, and thrift stores often have bins of this type of simple gear. It also is an easy tool for learning about battery discharge curves, loads, resistance, and testing capacity of different batteries.
This is a simple and inexpensive battery testing setup, best for comparing different batteries capacities, or load testing to check the state of charge. If you calculate the current in this circuit and use the clock to measure the time it takes to discharge the battery you can get a good measure of the capacity of the battery.
This type of device is good for testing different brands or types of batteries, to compare them, or to determine which best needs your needs. You can figure out the cost per mah, and take DMM readings to get a discharge voltage curve to see how the cells hold or lose voltage under load.
This type of information is great for learning about characteristics of batteries in general, and how different chemistries of batteries act under load, which will be invaluable for deciding the size, type and chemistry for your future projects.
|RefDes||Name||Value||Part Number||Digi-Key Part||Description|
|R1||RESISTOR||5.6||CFM12JT5R60||S5.6HCT-ND||RES 5.6 Ω 1/2W 5% CF MINI|