12V Car Battery Dissection

Materials: ★★★ Requires materials not commonly found in school laboratories
Difficulty: ★★★ Requires a more experienced teacher
Safety: ★★★ Only to be attempted with adequate safety procedures and trained staff

Categories: Electrochemistry

Alternative titles: Lead-Acid Car Battery Structure

Summary

A car battery is a lead-acid electrochemical cell that converts chemical energy into electrical energy. It consists of lead plates and sulfuric acid electrolyte, which react to provide the current needed to start a vehicle and power its electrical systems.

Procedure

Observe the structure of a lead-acid car battery, which contains six cells producing about 2.1 volts each, for a total of ~12 volts.
Identify the positive and negative plates made of lead compounds.
Note the sulfuric acid and water electrolyte that reacts with the plates to generate electricity.
Locate separators, which prevent direct contact between plates while allowing ionic flow.
Trace how the connectors, grids, and terminals direct the flow of electricity to the vehicle’s starter and accessories.
Understand that when the car is running, the alternator recharges the battery by reversing the chemical reaction.

Links

Hacking Open A Car Battery (for Lead and Acid) - TKOR:

📄 Anatomy of Car Battery - auto batteries: https://www.autobatteries.com/how-batteries-work/anatomy-of-car

Variations

None

Safety Precautions

Always wear safety glasses and gloves when handling car batteries.
Sulfuric acid is highly corrosive; avoid spills and neutralize with baking soda if they occur.
Batteries can release hydrogen gas—keep away from sparks or flames.
Lift carefully; car batteries are heavy and can cause injury.
Dispose of or recycle batteries through proper hazardous waste or recycling programs.

Questions to Consider

Why does a 12-volt car battery contain six separate cells? (Each cell produces ~2.1 volts, and six in series provide ~12.6 volts.)
What chemical reaction allows the battery to generate electricity? (The lead plates react with sulfuric acid to produce lead sulfate, water, and electrons.)
Why does heat shorten battery life? (High temperatures accelerate chemical breakdown and corrosion of the plates.)
How does the alternator keep the battery charged? (It supplies an electrical current that reverses the discharge reaction, converting lead sulfate back into lead dioxide and lead.)