Activity Industry Sector
Transportation

## Make a simple battery

### Activity Overview / Details

Hook activity:

Materials needed:

• Whiteboard
• Cutaway battery
• Alternator
• 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).

### Materials / Resource

• Worksheet: How much do you know about batteries? [ Download ] Student worksheet to be used for Opener.