Part of Unit: Fundamentals of Electrical and Electronic Systems
Lesson Plan Overview / Details
Battery technology starts with chemistry and the understanding of how unlike metals in the presence of acid can create electricity. This is a one-hour lesson in which students will be exposed to this basic technology.
In this lesson, students will learn basic concepts of battery technology. After an instructor-led discussion on battery basics, the students will use four lemons to create a simple battery. Students will work in teams of two in this instructor-led activity. They will also have a handout for reference. Students will use an LED to test their new batteries.
Students will start with two lemons to simulate a 'two-cell' battery. They will attempt to light the LED with this set-up. It won't light. They will then add two more lemons to make it a 'four-cell' battery. When this is done, the LED should light.
- Hook activity
- 10 Minutes
- Instructor demo
- 10 Minutes
- Lab activity
- 30 Minutes
- Wrap-up: What have we learned?
- 10 Minutes
California's 2008 CTE Standards
- T.C.C1.5 Use appropriate personal protective equipment and safety practices.
- T.C.C3.6 Understand the principles of converting energy from one form to another.
- T.FS.9.3 Understand how to organize and structure work individually and in teams for effe...
- T.FS.9.6 Participate as a member of a team and contribute to a group effort.
California Academic Content Standards (Reinforced)
Objectives and Goals
- Students will understand the importance of appropriate personal protective equipment and safety practices.
- Using lemons to construct a simple multi-cell battery, students will understand the principles of converting energy from one form to another.
- As a group, students will understand how to organize and structure work individually and in teams for effective completion of this task.
- Individually, students will work on their own, contributing to a group effort in the creation of a simple battery.
Materials required and preparatory steps
NOTE: Students will work in teams of two. The following items are required for one lemon battery (4 'cells').
1. Four lemons
2. Four -inch lengths of copper metal strips
3. Four -inch lengths of galvanized steel metal strips
4. Five short jumper leads with alligator clip ends
5. One LED
6. Worksheet: Making a Simple Battery
Additional items and materials needed for this lesson:
1. Safety glasses for all students
2. Digital volt-ohm meter (DVOM)
3. Automotive battery cutaway
4. Flashlight with two 'D'-cells
5. Steel wool pad (000) fine
6. Paper plates
7. Towels for mess clean-up
8. Trash bag for gathering waste at end of exercise
9. Worksheet: How much do you know about batteries?
10. Powerpoint slide show: Batteries -- Basics
On the classroom whiteboard:
1. Write down the following: Lesson for today: "How Batteries Work"
2. Draw the four-lemon circuit diagram on the whiteboard. Use the photo shown below. NOTE: To start with, the students will put together a simple two-lemon battery (per instructions on their worksheet). They will add lemons to learn concepts of boosting voltage and amperage.
Additional preparation steps:
1. Use a piece of steel wool to clean any corrosion or discoloration from the eight metal strips (four copper and four steel)
2. Lay out paper plates on the table to hold the lemons.
3. Provide to each student group plenty of paper towels.
4. Place trash bags strategically among the groups.
Activities in this Lesson
- Make a simple battery Hooks / Set
- Cutaway battery
- One lemon
- DVOM (Set to Volts low scale)
- Worksheet: How much do you know about batteries
- PowerPoint presentation slides 1 through 9
Instructor: As students walk in, have them pick up the How much do you know about batteries worksheet and start working on it while you're taking roll. This is an ungraded worksheet that will be used for discussion. It will get the students in tune with the topic for the hour.
Instructor: "Let's get started. Each of you picked up and completed the worksheet How much do you know about batteries. Hang on to those for now. We'll use it for discussion later in the lesson."
Instructor: "Here's a lemon. But it's more than just a lemon. It's also the basis for a battery. How do you think that's possible? (Call on students for answer vs. asking for a raise of hands)
Instructor: It's the basis for a battery because it contains acid. We're going to use the acid to create electricity on demand."
(Choose two students to assist):
- Have students take the lemon and insert two probes from a DVOM (Set meter to volts ‘super-low’ scale).
- Show voltage slowly climbing
"The meter shows electrical voltage or 'pressure'. Here's the way it works: We insert metal probes into the lemon which contains acid. The acid reacts on the metal probes to create a voltage potential. The meter is an electrical load. The load prompted the electricity to show a reading on the meter."
Instructor: "Batteries create electricity on demand. They do this when there's a complete circuit across the two battery posts."
(Begin powerpoint presentation here)
(Slide 1): "So here's the plan for today We're going to discover how batteries work. You'll learn some surprising facts as we go through the lesson today".
(Slide 2): "More specifically, we'll cover the following concepts:"
- How batteries create electricity on demand
- The first batteries and ancient history (You'll be surprised at this one!)
- How to make a simple battery
- Batteries -- Application to automobiles
Instructor: "Now take out the worksheets you filled out at the start of class. Be prepared to give it your best shot when I call on you for answers.
Instructor: Questions: (Call students out vs. asking for hands)
(Slide 3): " Electricity has been around for a long time. What was the first form of electricity?" Lightning from the sky.
(Slide 4): "Was this form of electricity usable?" Not really. In a few seconds, all the electrical power was absorbed into the earth.
(Slide 5): "Another form of electricity actually lived in the ocean. Any idea what that was / is?" Electric fish. This is a weird one: The ancient Greeks wrote of the pain killing effect of electric fish when applied to the soles of the feet.
(Slide 6): "The first battery: Does anyone have an idea of where and when it was made? Iraq around 2,000 years ago. It was a clay pot with a copper strip and metal rod attached. The acid solution required was likely grape juice.
(Slide 7): Do you think the ancients really understood the principles of storing electricity when they created the first battery? Maybe not. Many inventions are created before their basic principles are really understood. Here's an interesting fact: The Chinese invented gunpowder long before the principles of combustion were understood. The fact is this: You don't always have to understand why something works - just that it does.
(Slide 8): "Electricity and automobiles: On any vehicle, electricity is available in what two forms?" Generated (alternator) or stored (battery).
Instructor: (Hold up the cutaway battery).
(Slide 9): "The battery is used only to start the vehicle. Once the vehicle is running, what's the component that takes over to charge the battery and run the vehicle and all accessories?" The vehicles generator or alternator. (Hold up the alternator).
- Classroom: Instructor Show and tell: Demo / Modeling
- Automotive battery cutaway
- Working flashlight with d-cell batteries
Instructor: (Hold up the auto battery cutaway): "Here we have an automotive battery cutaway. As you know, it provides electricity on demand. It contains six different compartments or cells. We'll talk about why they're important a little later. Again, the battery doesn't 'produce' electricity until called on to do so. So how do we get the battery to do its work? Applying a load to the battery will prompt it to produce electricity. This means operating the vehicle starter, lights, or accessories."
Instructor: (Hold up the d-cell flashlight): "Here's a flashlight. Turn the switch ON, the bulb lights."
Instructor: (Remove one of the batteries from the flashlight): "Here's the battery from our flashlight. It does the same thing as any battery: Produces electricity when it's needed. Switch ON, puts a load across the battery, which then produces the electricity needed to light the bulb."
- Lab Activity: Worksheet-guided Lab / Shop
- Student worksheet: Making a Simple Battery
- All items listed in Materials and set-up list
Instructor: Hand out worksheet: Making a Simple Battery
Instructor: "We’ve discovered that batteries produce electricity when called upon to do so. Now we'll give you the opportunity to make a simple battery yourself."
Instructor: Hand out materials for this activity. See Materials and set-up list.
Instructor: "We’re going to start with two lemons to see how they perform. We'll add more later. You'll see why we have to do this."
Instructor: Carefully guide the students through the steps outlined on the 'Making a Simple Battery' worksheet.
IMPORTANT: Students should wear safety glasses before proceeding further.
NOTE: The LED is going to be fairly dim even with four lemons. You may have to shut off the classroom lights to make the LED's more visible.
- What have we learned? Closure
- Student Worksheet: Making a Simple Battery
- PowerPoint presentation slide #10
Instructor: Have students finish the 'Wrap-Up' section of their worksheet. Use this as a discussion point.
Instructor: "Now let's wrap up the lesson, and discuss what we've learned".
Questions: (Call students out vs. asking for hands)
1. "How can we make electricity with an acid solution?" (If we dip or submerge two unlike or different metals into an acid solution, we create potential electricity).
2. "How can we get a battery to produce electricity?" (Applying a load across the positive (+) and negative (-) 'posts' of the battery).
3. "Referring to the diagram you drew: What makes up a complete circuit?" (Battery, load, and wires or conductors to connect the battery and the load).
4. "What can a complete circuit accomplish?" (It can do work, turn a motor, light a bulb, etc.)
5. "On our lemon batteries: What happened with the LED when we wired two lemons or cells together?" (LED didn't light).
6. "What was our solution to make it work?" (We needed to add more electrical ‘power’, which is called amperage, or ‘amps’. We did this by wiring in more 'cells', the remaining two lemons).
Batteries: What's next?
Instructor: "In the next few days we'll learn more about automotive battery cleaning and testing. You'll also understand clearly why it's important to have all six battery cells working together and what can happen if they don't."
- Assessment Types:
- Projects, Interviews, Observations,
1. Interviews (questions to students): Instructor will ask key questions to guide students through the learning process. (Calling students out vs. asking for hands).
2. Observations: The Instructor will monitor student activities by walking around the classroom and observing. Instructor will assist as needed and answer any questions that the students might have.
3. Project: Students will follow a Worksheet to create and test a basic battery using lemons and other materials. They will test their battery using an LED. When the LED Iights, they have successfully created a basic battery.