What Is a Lead-Acid Battery and More Helpful Information

What is a lead-acid battery? How does it work? Is it safe and efficient? 

Are there any ideal applications for lead-acid batteries? Or has this technology become obsolete?

If you have questions like these, you're in luck. We have the answers to all you ever wanted to know about lead-acid batteries.

The truth is, the technology behind lead-acid batteries is over 100 years old. But, as you'll soon see, it still has many useful applications today.

We'll start our guide by explaining what lead-acid batteries are and how they work. Then, we'll go into detail about the pros and cons of using lead-acid batteries.

If you're wondering whether or not lead-acid batteries are right for your needs, read this guide.

What Is a Lead-Acid Battery?

The invention of the lead-acid battery dates all the way back to 1859. Since then, they have become more efficient and safer to use. Still, they remain quite similar to their original design.

These are rechargeable batteries powered by a chemical reaction between two main components: lead and diluted sulfuric acid. They do not hold a charge as well as most other rechargeable batteries, like Li-ion batteries. But they are very powerful for their size, which is why they're often used for automotive purposes.

How Does a Lead-Acid Battery Work?

This is an oversimplification, but here are the basics of how a lead-acid battery works. As the battery is discharged (being used), sulfate from the sulfuric acid bonds with the lead plates immersed in them. When the battery is recharged, the sulfate goes back to where it started.

This migration of ions causes a flow of electrons, that is, electricity. But the bonding of the sulfate to the lead causes the voltage to weaken as the battery is discharged.

Specifically, the surface area of the lead becomes coated by the sulfate. This reduces the amount of lead available to react with the acid. The acid itself also weakens as the sulfate leaves it.

Disadvantages of a Lead-Acid Battery

Lead-acid batteries are old technology and, thus, obsolete for many (but not all) modern applications. Here are a few of the disadvantages this poses.

1. The Voltage is Relative to Its Charge

A lot of rechargeable batteries, like the Li-ion battery in your cellphone, output just as much power at a full charge as they do at a low charge. This isn't the case with lead-acid batteries.

Lead-acid batteries only put out a strong voltage when fully charged. This voltage gets weaker and weaker as the battery discharges.

In most cases, the voltage is only useable when the battery is charged to 50% capacity or more. When the battery discharges below 50%, the voltage is typically too weak to use. Plus, using a lead-acid battery that's discharged below 50% could damage it.

2. Self-Discharge

Lead-acid batteries also discharge automatically, and somewhat quickly, even when you aren't using them. Higher temperatures will increase the dischage rates while lower temperatures will decrease it.

Thus, if you don't charge them often enough, lead-acid batteries die.

3. Not Ideal For Storing Energy

As you can see, these batteries are ideal for providing a short, powerful burst of energy. They are not, then, well-suited for storing energy, as in a solar power storage system.

4. Maintenance

Most batteries require no maintenance at all. With lead-acid batteries, the maintenance is minimal, but it's still more than nothing.

Corrosion will naturally build up on the battery terminals over time. You'll need to clean this off once in a while as well.

Lastly, flooded lead-acid batteries must be kept upright at all times. Otherwise, they might leak.

5. Toxic Fumes

These batteries must be charged in a well-ventilated area or else they pose a serious health hazard. That is, they emit hydrogen gas fumes while charging, which are poisonous.

6. Size

Lead-acid batteries are kind of bulky compared to other battery types that might be used for the same job. If space is an issue, a different battery type might be ideal.

Advantages of a Lead-Acid Battery

Despite the disadvantages described above, there are also plenty of benefits to using lead-acid batteries. Here are the most important examples.

1. They're Cheap

This is largely the number one reason lead-acid batteries are used today. They're cheap to produce and cheap to buy.

2. There Are Still Many Useful Applications

Also, lead-acid batteries still work great for many applications, such as powering a golf cart. As mentioned above, they're quite powerful when fully charged. Thus, they're great for anything that needs a lot of power for a short amount of time.

3. They're Resilient

These are very hearty batteries that can withstand the kind of abuse that might ruin other batteries. Overcharging, for example, is not a problem with lead-acid batteries.

4. They're Recyclable

Considering they contain lead and acid, you wouldn't expect these batteries to be very eco-friendly. And, to be honest, they would be quite hazardous if you simply tossed them into a landfill.

But, the fact is, these batteries can be recycled. In fact, most locations require it by law. Therefore, lead-acid batteries get recycled more often than many other types of batteries.

Is a Lead-Acid Battery Right For You?

What is a lead-acid battery? It might just be the perfect battery for your needs. Or perhaps not. 

In any case, you now know how to decide this for yourself. When considering which type of battery you need, remember this guide.

Ready to learn more about your battery options? Then click here to read What Are the Different Car Battery Types?