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A battery is a device that changes chemical energy into electrical energy. It is a common power source for many household and industrial applications. Batteries need to be of a certain strength, or electric potential, in order to power devices successfully. Electric potential determines how strongly electricity is pushed through a circuit, much like pressure determines how strongly water is pushed through a hose. After extended use, batteries can drain to a point where the device they are powering may not work properly or at all. Using a Voltage Probe to make a battery tester is a great way to determine whether the battery you intend to use has enough electric potential to run your device.


In this project, your challenge is to design and build a device for testing the usability of an AA battery using a Vernier Differential Voltage Probe. A battery will be considered “dead” if the voltage is below 1.2 volts. Your device, when activated, should cause the alligator clips on the voltage probe to touch the metal terminals on a battery. After testing the battery, your program should give feedback indicating whether the battery is good or needs to be replaced.

Sensors and Equipment

This experiment features the following sensors and equipment. Additional equipment may be required.

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This experiment is #8 of Vernier Engineering Projects with LEGO® MINDSTORMS® Education EV3. The experiment in the book includes student instructions as well as instructor information for set up, helpful hints, and sample graphs and data.

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