In the previous chapters, we learned about the basic concepts and terminology of batteries. Now it’s time to explore the different battery types that are commonly used in everyday life.
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Let’s begin with one of the oldest and most widely used rechargeable batteries—the lead-acid battery.
What is a lead-acid battery?
The lead-acid battery was invented in 1859 and remains one of the most widely used rechargeable battery technologies today. Although newer battery chemistries such as lithium-ion have become popular for portable devices, lead-acid batteries are still the preferred choice for many high-power applications.
The battery used in most cars and motorcycles is a lead-acid battery.
If you’ve ever seen one, you’ll notice that it’s much larger and heavier than the batteries used in smartphones or laptops. This is because lead-acid batteries have a relatively low energy density, meaning they store less energy for their size and weight.
Where are lead-acid batteries used?
Because of their size and weight, lead-acid batteries are generally used in applications where portability is not important.
Some common applications include:
- Cars and motorcycles
- Solar energy storage systems
- UPS (Uninterruptible Power Supplies)
- Inverters
- Emergency backup power systems
These applications require a battery that is reliable, inexpensive, and capable of delivering high currents when needed.
Advantages of lead-acid batteries
One of the biggest advantages of a lead-acid battery is its ability to deliver very large currents in a short period of time.
Although it has a relatively low energy density, it has a high power capability, making it ideal for applications such as starting vehicle engines. Lead-acid batteries are also inexpensive, widely available, and relatively easy to maintain, which is why they continue to be used even after more than a century.
Nominal voltage
Lead-acid batteries are available in several voltage ratings, with the most common being:
- 2 V
- 6 V
- 12 V
- 24 V
A typical car or motorcycle battery is rated at 12 V.
Internally, a 12 V lead-acid battery consists of six cells connected in series, with each cell having a nominal voltage of approximately 2 V.
What is an SLI battery?
The lead-acid battery used in most vehicles is known as an SLI battery, where SLI stands for:
- Starting
- Lighting
- Ignition
As the name suggests, these batteries are designed to provide the high current needed to start the engine while also powering the vehicle’s lighting and ignition systems.