yo8ssv/batterytesting

Low cost hardware+software system for testing battery capacity

Simple battery testing tool

This project aims to build a complete and affordable setup for DIY battery testing.

Features

• Compatible with various battery types
• Battery capacity testing
• Internal resistance measurement
• Nice graphs
• Minimal component count, low cost

Example test result

Required parts

• Computer with Python 3
• Arduino Uno
• Constant current load (example schematic included in the hardware directory)

Usage

• Connect all parts together (load is not applied until the software is started)
• Start the measurement with python .\desktop\measurebattery.py [COM PORT] [CUTOFF VOLTAGE]
• Battery will be discharged until it reaches specified voltage or 2.8V if no voltage was specified
• Enter your battery name in the first line of the resulting file ( battery_[TIME].txt )
• Render the graph with python .\desktop\rendergraph.py [FILE NAME]

Accuracy

Measurement accuracy depends heavily on how stable your PC USB voltage is, after calibration you should be able to get around 5% accuracy for capacity.

Accurate measurement of internal resistance requires good battery connection and good PCB design for your constant current load, stock design should be able to measure within 10%.

Contributing

Contributions are welcome, feel free to submit your own test results or hardware/software improvements.