Batteries: How They Make Things Work
Learner: Tucker, age 10
Goal: Tucker will explain that a battery provides electrical energy, identify the positive and negative terminals, and build a simple circuit that lights a bulb or LED.
Materials
- One AA or AAA battery
- Small flashlight bulb in a holder, or a battery-powered LED
- Two insulated wires with the ends stripped, or two pieces of aluminum foil
- Small flashlight or another battery-powered object
- Paper and pencil
- Optional: a coin, paper clip, plastic ruler, wooden pencil, and piece of cardboard for testing materials
Safety: Use only ordinary household batteries. Do not open, cut, heat, or put batteries in water. Never connect the two ends of a battery directly with wire for more than a moment because the wire and battery may become hot. Do not use wall electricity.
Lesson
1. Hook: The Mystery of the Flashlight — 5 minutes
Hand Tucker a flashlight. Ask:
- “What makes the flashlight produce light?”
- “Where do you think the energy comes from?”
- “What might happen if we take the battery out?”
Let Tucker predict, then remove the battery and test the flashlight. Explain that a battery stores chemical energy and can change it into electrical energy. The electrical energy can then make light, sound, movement, or heat.
2. Show It: The Parts of a Battery and a Circuit — 10 minutes
Show Tucker the battery. Point out the two ends:
- The end marked + is the positive terminal.
- The end marked − is the negative terminal.
Explain:
A circuit is a complete path that electricity can travel through. A battery supplies energy, wires provide a path, and the bulb or LED uses the energy. If the path is broken, the bulb will not light.
Draw this simple circuit on paper:
battery (+) → wire → bulb → wire → battery (−)
Tell Tucker that electricity must travel around the complete loop. The battery does not make the bulb light when only one side is connected.
3. Do It Together: Build a Circuit — 15 minutes
Help Tucker connect one wire from the positive end of the battery to one contact on the bulb holder. Connect the second wire from the other contact on the bulb holder to the negative end of the battery.
Ask:
- “Is the path complete?”
- “What part of the circuit is using the electrical energy?”
- “What do you think will happen if we disconnect one wire?”
Disconnect one wire and observe that the bulb goes out. Reconnect it. Then switch the two wires around. Explain that the bulb still works because the circuit is complete, although some LEDs work only when connected in the correct direction.
If using foil instead of wires, press one foil strip against each battery terminal and touch the other ends to the two bulb contacts. Keep the foil from touching both battery terminals directly.
4. Tucker Does It Alone: Circuit Challenge — 15 minutes
Give Tucker the battery, wires, and bulb. Ask him to build the circuit without step-by-step help. He should draw his circuit before or after building it and label:
- positive terminal
- negative terminal
- energy source
- part that uses the energy
- complete path
Then ask Tucker to make one change at a time and record what happens:
- Disconnect one wire.
- Reconnect the wire.
- Try connecting the bulb using only one wire.
- If available, try a second battery with adult supervision. Ask whether the bulb seems brighter. Do not connect batteries in a way that causes wires to touch both terminals directly.
5. Optional Investigation: Conductors and Insulators — 7 minutes
Keep one place in the circuit open. Let Tucker place each test object into the gap so it either completes the circuit or does not.
Test the coin, paper clip, plastic ruler, wooden pencil, and cardboard. Tucker records each result:
| Object | Did the bulb light? | Conductor or insulator? |
|---|---|---|
| Coin | __________ | __________ |
| Paper clip | __________ | __________ |
| Plastic ruler | __________ | __________ |
| Wooden pencil | __________ | __________ |
| Cardboard | __________ | __________ |
Explain that metals are usually good conductors, while plastic, dry wood, and cardboard are usually insulators. The graphite inside a pencil may conduct a little electricity, but it may not make this bulb light clearly.
6. Brief Recap — 5 minutes
Ask Tucker to complete these sentences aloud:
- “A battery changes ______ energy into ______ energy.”
- “A circuit must be ______ for electricity to travel.”
- “The two ends of a battery are called the ______ terminal and the ______ terminal.”
- “A metal that lets electricity pass through it is called a ______.”
Expected answers: chemical, electrical, complete, positive, negative, conductor.
Quick Check of Understanding
Ask Tucker to answer without looking back:
- Why did the bulb go out when one wire was disconnected?
- What are the two terminals on a battery?
- What three main things are needed for the simple circuit?
- Is a coin more likely to be a conductor or an insulator? Why?
Expected answers: The circuit was no longer complete; positive and negative; a battery, a conducting path such as wires, and a device such as a bulb; a conductor because it is metal and allows electricity to pass through.
Make it easier: Build the circuit together first, using only the battery, two wires, and bulb, and have Tucker copy a labeled circuit diagram.
Make it harder: Ask Tucker to design a circuit with a switch made from cardboard and a paper clip, then explain how the switch opens and closes the circuit.