How A Car Battery Works - basic working principle

Summary

This video explores the function and operation of 12-volt lead-acid car batteries, essential for starting combustion engines. It explains the chemical reaction within the battery that converts stored chemical energy into electrical energy, highlighting its rechargeability. The script delves into the battery's role in powering the starter motor, the alternator's function in recharging, and the importance of maintaining battery health. It also covers the basics of electricity, DC vs. AC current, and the chemical processes within the battery cells, providing a comprehensive understanding of these vital automotive components.

Takeaways

• 🚗 The 12-volt lead-acid car battery is a crucial component in combustion engine vehicles, providing the necessary energy to start the engine and power electrical systems.
• 🔋 Lead-acid batteries store energy in chemical form rather than as electricity, and they are rechargeable by reversing the chemical reaction with an external electrical supply.
• 🔌 The battery is connected to the starter motor, which uses a large current to turn the engine's flywheel and crankshaft, initiating the combustion process.
• 🔌 The alternator, driven by the engine, generates electricity to recharge the battery and supply power to the vehicle's electrical systems when the engine is running.
• 🔋 The car battery's energy storage is reduced when the starter motor operates, necessitating recharging by the alternator to maintain its capacity.
• 🛠️ The battery consists of six cells, each producing around 2.1 volts, connected in series to provide a total voltage of approximately 12.6 volts.
• 🔄 The battery's plates, made of lead and lead oxide, are part of a chemical reaction that releases electrons, with the size of the plates determining the current capacity.
• 🏎️ The battery's operation involves the flow of electrons from the negative to the positive terminal, despite conventional current theory suggesting the opposite.
• 🔬 Chemical reactions within the battery involve the formation of lead sulfate on the electrodes and the release or capture of electrons, which can be reversed by recharging.
• 🔋 A fully discharged battery can become difficult to recharge, and sulfate buildup can reduce the battery's effectiveness, requiring maintenance or replacement.
• 🔧 To test a car battery's voltage, a multimeter is used, with readings around 12.6 volts indicating proper function, and lower readings suggesting issues with the battery.

Q & A

What is the primary function of a 12-volt lead acid car battery?

The primary function of a 12-volt lead acid car battery is to provide the electrical energy needed to start the combustion engine and to supply power to the car's electrical systems when the engine is off.

Why are lead plates submerged in an acid in a lead acid battery?

Lead plates are submerged in an acid to create a chemical reaction that releases energy, providing voltage and current. This chemical energy is then converted into electrical energy when needed.

How does a car battery recharge itself?

A car battery recharges itself by receiving electricity from the alternator, which is rotated by the engine. The alternator generates electricity that is fed back into the battery to reverse the chemical reaction and recharge it.

What is the role of the starter motor in a car's electrical system?

The starter motor's role is to engage a small gear onto the engine's flywheel, turning the crankshaft to start the combustion engine. It requires a large current for a short period to do so.

How does the alternator help in maintaining the battery's charge?

The alternator generates electricity when the engine is running, which is fed back into the battery to recharge it. It also provides the electrical power for the car's systems when the demand exceeds what the alternator can supply.

What happens if the car's battery is completely drained and cannot start the engine?

If the battery is completely drained, it cannot provide enough electricity to start the engine, and the car will need to be jump-started to recharge the battery and restart the engine.

What are the six separate chambers in a car battery called, and what is their purpose?

The six separate chambers in a car battery are called cells. Each cell generates around 2.1 volts of direct current, and they are connected in series to provide a total voltage of around 12.6 volts.

What is the purpose of the plate straps in a car battery?

Plate straps, made from lead, connect the plates in each cell to form a series connection, allowing the voltage from each cell to add up to provide the total battery voltage.

How does the chemical reaction in a lead acid battery involve the lead oxide and lead plates?

The chemical reaction in a lead acid battery occurs when the lead oxide of the cathode reacts with sulfate in the electrolyte to form lead sulfate and release oxygen ions, while the lead of the anode reacts with sulfate ions to also form lead sulfate and release electrons.

Why are the positive and negative plates in a battery separated by an envelope separator?

The envelope separator is a porous material that prevents the positive and negative plates from coming into direct contact, which would short-circuit the battery, while still allowing ions to flow through.

What is the significance of the electrolyte liquid in a lead acid battery?

The electrolyte liquid, a mixture of sulfuric acid and water, is crucial for the chemical reaction in the battery. It facilitates the reaction between the lead oxide and lead plates, enabling the release and capture of electrons.