Battery Tester
Project Summary
We built a device to test the current flow through a battery as it lights up a lamp.
Project Description
This is one LEGO NXT project we hope to use for a practical purpose. When we are doing robots projects, we end up with a lot of partially used AA batteries. We thought it would be fun to have an automated way to test those batteries so that we use those with some life left. Since we know it is best to test a battery with a load (instead of just reading the voltage), we set up a circuit with a small incandescent lamp and a Vernier Current Probe.
The NXT mechanism advances a battery into position with one motor. A second motor moves contacts into place to touch the two ends of the battery. The NXT Sensor Adapter allows the NXT to read the current. If the battery causes much current to flow, you can also see the lamp light up. The NXT makes a decision based on the current that flows. If the current is above the threshold level, the battery is moved to the left bin. If the battery is too weak, the battery is moved to the right bin.
It is relatively easy to make a device to do this test a few times. It is very difficult to make one which will do it over and over again without jamming or failing.
Demo Movie
The movie of this project shows the sorting of four batteries. The last part of the movie shows a close-up view of a battery going through the testing process.
Project Downloads
Download the Battery Tester MINDSTORMS NXT program »
Project Equipment
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