Structure of lead acid batteries

With a push for green energy increasing each day, there is a need to store and efficiently utilize that power. Sure, you can create 100 Gigawatts from a large enough solar plant or wind farm. But, all that is useless without storing and harnessing that energy efficiently. That is where batteries come in. Most circuits that don’t connect to the main power supply, from smartphones to cars, have a battery.

But how can such a compact device power a mechanism 15 times its weight? Well, this guide will tell you all about it. In favor of its popularity, we’ll try to explain the structure of the lead acid battery and how it works.

Basic Structure of Lead Acid Battery

Lead acid batteries consist of two electrodes – the lead that forms the negative plate and lead oxide that creates the positive one. Both are dipped in sulfuric acid, which serves as the electrolyte. Between the plates are grid meshes that distribute the charges evenly throughout the battery. Both the plates are separated with an insulating PE separator, but the electrolyte remains in contact with both. You can observe the structure in the image below.

Basic Structure of Lead Acid Battery
Basic Structure of Lead Acid Battery

How Do Lead Acid Batteries Work?

In a discharging state, i.e. when there is a load between the two terminals, the lead from the positive terminal loses electrons to form positively charged ions. Those react with the sulfate ions to form lead sulfate. On the positive terminal, the lead oxide takes in the electrons and splits them into lead and oxide ions.

The oxide component reacts with the hydronium ions in the electrolyte to form water. The lead deposits on the electrodes, and the discharging cycle continues. Thus, the concentration of lead sulfate in the electrolyte determines the battery’s discharge rate.

In a charging state, the reaction occurs in reverse. Both water and lead sulfate break down into ions due to electrolysis. The lead ions deposit back onto the negative electrode after gaining electrons, whereas the sulfate ions react with hydrogen to form sulfuric acid. All the excess oxide ions react with the lead ions to form lead oxide.

Types of Lead Acid Batteries

While their working principle remains the same, different types of lead-acid batteries suit various applications. Some of the most commonplace ones include the following.

Flooded Lead Acid Battery

It is the simplest form of lead acid battery. Flooded batteries don’t have a valve as they are designed for one-time use. You can charge and recharge for a few cycles, but they eventually give out. They are sealed tight, so there is no way to replace the electrolyte. As they can often contribute to total e-waste generation, they are only used for small circuits.

Advanced Glass Mat (AGM) Battery

AGM batteries are sealed batteries that use multiple cells in parallel. That reduces the internal resistance, making the discharge/recharge process much faster. It also allows you to draw a high magnitude of current from them, which is why they are popular in automobiles. Moreover, AGM batteries are waterproof and can function in a wide range of temperatures.

ExpertPower 12v 33ah Rechargeable Deep Cycle Battery

The components that go into the production of ExpertPower’s Deep Cycle Rechargeable Batteries are of the highest possible standard. Our lead acid batteries are typically utilized in the following applications: home alarm systems, uninterruptible power supplies (UPS), lighting equipment, general electronics, home security systems, emergency systems, medical devices, electric scooters, solar collectors, wheelchairs, and a wide variety of other applications. You should always make sure to use the most energy-efficient batteries that are available, whether it’s for the SECURITY of your home, the MOBILITY of your machine, or even just a personal HOBBY.

Alternatives to Lead Acid Batteries

Lead acid batteries are inexpensive to manufacture and can be used multiple times. However, there is a growing concern with their disposal, as the plastic and sulfuric acid that goes to waste can harm the environment.

That calls for alternatives that remain just as effective, if not more, without harming the environment. Some of the promising ones are:

Ni-Cd Batteries

Nickel-Cadmium batteries have proven effective in various hybrid vehicles and small equipment such as calculators. Button cells are usually of this type. Instead of lead oxide, nickel oxide is used as the cathode, whereas cadmium acts as the anode. The electrolyte is a metal hydride, often sodium hydroxide, which is safer than acids for disposal.

These batteries last for thousands of more cycles than lead acid batteries. Additionally, the electrodes can be compressed into thin sheets, making them much more space efficient. Nevertheless, the high cost of nickel and cadmium mining makes their manufacturing costs sky-high.

Li-Ion Batteries

A number of Nikon cameras can take advantage of the EN-EL15c, which is a rechargeable lithium-ion battery pack. When used with Nikon cameras that have the ability to charge batteries while they are still in the camera, it can be charged using either the MH-25a battery charger or the EH-7P charging AC adapter. Both of these chargers can be purchased separately.


Supercapacitors utilize a liquid between two capacitor plates to increase the retention of any charges. Theoretically, a supercapacitor can retain a high-density charge for up to 10 years with a 20% loss. Today, they are relatively expensive to manufacture, so only a couple of high-end electric sports cars use supercapacitors.


Hydrogen Fuel Cells

Another way to extend the life of batteries while keeping them lightweight is to make the electrolyte refillable. That is the principle behind fuel cells. They use hydrogen obtained from electrolysis to react with the oxygen from the air to form electricity and water.

Contrary to popular belief, fuel cells have been around for decades. NASA used them to power electronics on the Apollo 11 aircraft that took Neil Armstrong and Buzz Aldrin to the moon. Today, fuel cells are expensive since they use rare metals like platinum and palladium as electrodes. Although, variants are underway that use less costly options such as titanium, cadmium, or potassium oxide.




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