Battery Blogs: What Is a Lead Acid Battery?

Lead-acid batteries are one of the most popular in the world, with a global market value of almost $40bn each year. But what is a lead-acid battery, and why is it so different from its counterparts?

This article looks at what’s involved in a lead-acid battery, its use cases, and its advantages and disadvantages in everyday use cases.

What Is a Lead-Acid Battery?

Lead-acid batteries are wet-cell batteries most often found in automobiles. They allow for high surge currents and have a low density of energy, which enables them to start the engine in an automobile.

Lead-acid batteries are relatively cheap to make. This has made them popular all over the world.

Their surge currents also mean they’re popularly used in emergency backup systems to kick-start generators and vital equipment such as life support machines or cell phone towers.

Also, forklift trucks have another unique use for lead-acid batteries: The weight of the lead-acid battery allows for counterbalance.

How Does a Lead-Acid Battery Work?

Lead-acid batteries have a hazardous liquid electrolyte. This liquid reacts with a metal grid through electrochemical oxidation.

When electrons transfer from the positive electrode (+) to the negative (-), water occurs. Then, oxygen gas appears at the negative electrode, with hydrogen at the positive.

The reactions that occur inside the battery produce water and hydrogen gas. The reaction between water and lead plates produces lead sulphate.

The reaction between the acidic electrolyte and lead plates results in the production of sulphate, which is a solid. When there is high resistance in the negative circuit, oxide forms on the plates and inhibits the battery’s performance if left too long.

Advantages and Benefits

Many benefits come with using lead-acid batteries. Their biggest advantage is their low cost, making them an excellent choice if working on a tight budget.

They’re also rechargeable and have a long life cycle when using and recharging. Most car batteries now come with 1 – 5 year warranty depending on the application and operating temperatures.

The performance of lead-acid batteries is consistent. This consistency makes them an excellent choice for those that need a battery that will perform well but won’t fail. It makes them perfect for situations where reliability is paramount, such as in a vehicle.

Disadvantages and Negatives

Lead-acid batteries are also well known for their disadvantages. One of the biggest disadvantages is that they have a short lifespan in storage, so when no power is drawn them, the batteries need charging every month or so. Lead-acid batteries also have a low tolerance for overcharging, damaging the battery, and leaving it unable to charge.

The biggest disadvantage of using a lead-acid battery is that it’s very corrosive. It can be problematic if the necessary precautions aren’t taken to avoid contact with the electrolyte. When in contact with skin, the battery will burn and cause long-term damage, especially in an acidic state.

These disadvantages were the driving force behind developing another type of lead-acid battery known as an AGM battery, which aims to solve many of these issues while retaining the benefits of a lead-acid battery.

AGM Battery vs Lead-Acid Battery

AGM stands for Absorbed Glass Mat. These AGM batteries are otherwise known as sealed lead-acid batteries. They differ slightly in their uses of lead-acid batteries and also in how they work.

How Does an AGM Battery Work?

An AGM battery differs from other lead-acid batteries in that it uses fibreglass mats to hold the electrolyte. This helps prevent gases from escaping and protects the battery from overcharging, degrading the battery.

It might sound like a disadvantage, but it isn’t because it allows charging the battery more often without damaging it. It also increases its lifespan by allowing up to 80% discharge, whereas most lead-acid automotive batteries only allow 15-20% discharge.

The fibreglass separator also prevents the sulfation of the lead plates by absorbing sulphur dioxide. Sulphation is a process that pits the surface of battery plates and damages the battery.

That is what makes lead-acid batteries less efficient over time. It also increases their lifespan because the batteries are able to charge more often.

Advantages and Benefits

There are some big advantages to using an AGM battery. The sealed state of the battery means that it’s also well-suited for a marine environment, where there are extra challenges to charging. That’s because the lower pressure in an AGM battery means that gases won’t escape out of the battery during charging.

AGM batteries also have a low self-discharge rate, so they can charge for longer without drawing down. It makes them an excellent choice for those that need long-term power storage.

The rise of electric vehicles is causing a rise in AGM batteries sales. That’s because they provide much more resilience to the demands of the high-voltage lithium-ion battery in an electric car.

Another benefit of the sealed AGM battery is that the hydrogen and oxygen gas produced during charging absorbs into the fibreglass mats, meaning there’s little reason to worry about a dangerous gas escape.

The Lead-Acid Battery Is Still Popular

Both types of lead-acid batteries have many advantages, but for the most part, their longevity and reliability makes them perfect for use in the automotive industry

Yet, for an electric vehicle, making sure the battery won’t rust or fail in the future is key. Thus, an AGM battery will provide much more resilience.

Whatever your battery needs, get in touch with us today to find the lead-acid battery that’s right for you and your business.