Vernier Software and Technology
Vernier Software & Technology

Battery Tester


Batteries are a common power source for many household and industrial applications. They need to be of a certain strength, or voltage, in order to power devices successfully. After extended use, batteries can drain to a point where the device they are powering may not work properly or at all. Many battery-operated toys, calculators, and music players have labels warning you not to mix old batteries with new batteries. The reason is that newer batteries will drain faster to make up for the lack of power in the older batteries. A great way to determine whether the battery you intend to use has enough voltage to run your device is by using a battery tester. In this project, your challenge is to build a sensor-controlled robotic device that measures the voltage of a AA battery and tells you if it is good or needs to be replaced.


In this project, you will design and build a device for testing the usability of a AA battery. Your device should be able to detect the presence of a battery, measure its voltage with a Vernier Differential Voltage Probe, and give an audio indicator of the battery status. Batteries will be inserted and removed from the device by the operator. Your device should incorporate a motor to touch the red clip on the Differential Voltage Probe to the positive terminal of the battery and the black clip to the negative terminal. Your program should judge the strength of the battery based upon a pre-defined voltage limit. If the voltage is above the limit, the robot should give a recognizable audio indicator, such as “high” or “good.” If the voltage is below the limit, it should give a different audio indicator.

Sensors and Equipment

This project/activity features the following Vernier sensors and equipment.

Additional Requirements

You will also need NXT Sensor Adapter and a LEGO MINDSTORMS NXT robotics system.

Standards Correlations

See all standards correlations for STEM 2 with Vernier and LEGO® MINDSTORMS® NXT »

STEM 2 with Vernier and LEGO® MINDSTORMS® NXT

See other experiments from the lab book.

2First-Class Levers
3Audio Assistant
6String Tension Tester
7Gas Pressure
8Yeast in Action
9Grip Strength
10Cartesian Diver
12Lemon Battery
13Battery Tester
14Solar Cells
15Solar Tracker
16Mapping a Magnetic Field
18Migrating Robot
19Magnet Finder
20Mine Sweeper

Project/activity 13 from STEM 2 with Vernier and LEGO® MINDSTORMS® NXT Lab Book

<em>STEM 2 with Vernier and LEGO<sup>®</sup> MINDSTORMS<sup>®</sup> NXT</em> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

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