How do 24V Chargers Work? The Surprising Facts You Need to Know!

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How do 24v Chargers Work

Unlock the mystery of ‘How do 24v Chargers Work’. Empower yourself with this essential tech knowledge today!

If you have ever used a 24v charger, you might have wondered how it works. How does it charge different types of batteries? For example, lead acid, lithium-ion, or nickel metal hydride? How does it know when to stop charging and when to start again? How does it prevent overcharging, undercharging, or damaging your batteries?

How do 24v chargers work? The answer is that they use a multi-stage charging process. This process adapts to the battery’s condition and chemistry. They can charge multiple battery types by using different voltage and current settings.

But that’s not the whole story. There are more things you need to know about 24v chargers. You should learn about the different stages of charging. You should also learn the benefits and drawbacks of each battery type. You should also learn the best practices for using and maintaining your 24v charger.

I will explain everything you need to know about 24v chargers in a simple and easy way.

So, let’s talk shop.

Feature12V Charger24V Charger
Voltage Output12 volts24 volts
Charging TimeLongerFaster
Battery CapacityLower capacity batteriesHigher capacity batteries
CostLess expensiveMore expensive
ApplicationsSmaller vehicles (motorcycles, ATVs, boats)Larger vehicles and equipment (trucks, RVs, industrial equipment)

Key Takeaways

  • 24V chargers utilize multi-stage processes for optimal charging.
  • Different battery types can be efficiently charged with 24V chargers.
  • Choosing the right charger depends on battery system requirements.

How do 24v Chargers Work – Three-Stage Battery Charging

24-volt chargers usually work on a three-stage staggered charging process.

But what does a staggered charging process do? Let’s take a look.

Bulk Stage

The first stage of battery charging is the bulk stage. In this stage, a 24v charger provides the highest voltage and amperage it is rated for. This is important to replenish the battery’s energy quickly. The battery’s maximum charge without overheating is called its natural absorption rate. This stage counts for 80 percent of the charge.

Absorption Stage

Next comes the absorption stage. Here, the voltage and charging current are reduced. This ensures the battery gets fully charged without damage. It’s essential to have the correct absorption set point. This prevents harmful overcharging.

Float Stage

Lastly, we have the float stage. The charger continues to provide a small amount of current to the battery. It uses this current to maintain the battery’s full charge indefinitely. This prevents self-discharge and keeps the battery ready for use at a moment’s notice. The float stage is important because it guarantees a long, healthy life for your 24v batteries.

Key Differences between 12V and 24V Chargers

So, that is all well and good, but what’s the difference between a 12-volt and a 24-volt charger?

Let’s see.

Voltage Output

The main difference between 12V and 24V chargers is their output voltage. A 12V charger provides 12 volts of output, while a 24V charger delivers 24 volts. When charging batteries, match the charger’s output voltage with the battery’s voltage rating. So, use a 12V charger for 12V batteries and a 24V charger for 24V batteries.

Charging Time

Charging time varies between 12V and 24V chargers. Generally, a higher voltage charger can charge a battery faster than a lower voltage one. 24V chargers take less time to charge a 24V battery compared to a 12V charger charging a 12V battery. Charging time also depends on factors like battery capacity and the charger’s current rating.

Battery Capacity

Battery capacity refers to how much energy a battery can hold. 12V chargers are designed for 12V batteries with lower capacities. 24V chargers work for 24V batteries with higher capacities. When charging a battery, use a charger that matches the battery’s voltage. Use a charger that matches the battery’s capacity requirements. This avoids potential damage.


The cost of 12V and 24V chargers can differ. 24V chargers are generally more expensive than 12V chargers. They are designed for higher voltage and capacity batteries. The cost also depends on factors like the charger’s features, efficiency, and quality. So, choose a charger that meets your needs while considering its cost-effectiveness.


12V and 24V chargers have different applications. The applications depend on the type of device they are meant to charge. 12V chargers are commonly used for smaller vehicles. These include motorcycles, ATVs, and small boats.

On the other hand, 24V chargers are suitable for larger applications. These include commercial trucks, RVs, and industrial equipment. Consider your device’s specific requirements before selecting the right charger.

The Evolution of 24 Volt Charger Technology

24V chargers weren’t always this good!

Smart Chargers

24-volt charger technology has come a long way. Nowadays, we have smart chargers that use microprocessor-regulated charging profiles. These chargers usually have 2, 3, or even 4 stages, which is way more sophisticated than older models. Modern smart chargers make sure that a battery’s voltage is optimally charged and maintained. This helps keep our batteries healthier and prolong their lives.

Older 24 Volt Chargers

In the past, 24-volt chargers were not as efficient or safe. Most of them would continue to charge once the battery was full, and that would result in overcharging. This could lead to inflated batteries. It could also cause shorter lifespans. It could even damage the equipment they’re connected to. So, it’s a good thing that we have smart chargers now!


You may have heard people discuss equalization or the need to equalize batteries. You might be wondering what it is and whether you need to do it.

Well, don’t worry, I’ve got you covered.

Here’s the thing: The process of equalization involves a controlled overcharge. It increases the voltage of lead-acid batteries, ensuring all cells are at a similar level. This helps to prevent battery failure and prolongs the battery life.

Equalization improves the health of the batteries. It removes sulfate buildup on the battery plates, which can decrease the battery’s capacity. Additionally, it balances the voltage between cells. This is important for proper battery function.

I recommend regular equalization for wet batteries. Doing so will keep them working efficiently and increase their lifespan. Just remember to follow the manufacturer’s instructions for equalizing your particular battery model.

Wet batteries, also known as flooded lead-acid batteries, contain liquid electrolytes. They are often used in boats, recreational vehicles, and solar systems. Equalization is particularly important for these types of batteries.

Equalization helps maintain the wet batteries’ performance. It keeps their capacity at an optimum level. Without regular equalization, these batteries are likely to develop issues, reducing their lifespan.

And here’s another thing: equalization applies to both single battery setups and batteries wired in series. For single-battery setups, equalization helps to prevent battery failure and prolongs the battery life. For batteries wired in series, you can buy a battery balancer to keep each battery at the same voltage level.

24-volt Charger Sizes

One size might not always fit all. Here’s why.

Small Chargers

Small 24-volt chargers usually have lower output currents, perfect for smaller battery systems. They’re compact, lightweight, and user-friendly. These chargers are used for recreational vehicles, boats, and small off-grid power systems. One example is a 24-volt charger with low milliamp outputs, typically ranging from 100 to 500 mA. You can easily plug it into a standard 115-volt outlet and keep your batteries healthy*. Small chargers are ideal for day-to-day use and maintaining charge levels.

*Please note that if a charger delivers 65 amps or more, it might need a 20-amp circuit.

Medium Chargers

Medium-sized 24-volt chargers are designed for more hefty battery systems. They usually have a higher output current, around 10% to 25% of the battery’s Ah rating. For instance, if you have a 100Ah battery, a medium charger should be rated between 10A and 25A.

These chargers work well for larger off-grid systems, industrial equipment, and electric vehicles. They can handle higher-capacity batteries and charge them faster while providing safe, reliable charging.

Large Chargers

Large 24-volt chargers are built for heavy-duty use and high-capacity batteries. They can provide charging currents above 25A. This allows for rapid charge times and efficient charging. These chargers are commonly used for industrial applications. They are also used for large electric vehicles and heavy machinery. A large charger can accommodate your battery system’s needs. It won’t compromise effectiveness or safety. 

The main aspect to remember is not to use a charger with a higher voltage than required, as this may harm your battery system. The maximum recommended voltage for a 24-volt system is 29.6 volts.



How to Choose the Right 24V Charger

When it comes to picking the right 24-volt charger, there are a few different things to think about.

First, think about the type of battery you’re working with. Most chargers will work with all battery types except for gel cell batteries. So, make sure to choose a charger that’s compatible with your specific battery.

Next, consider power requirements. Some chargers work with a 110-volt outlet, while others require a 220-volt outlet. It’s important to choose a charger compatible with your power outlets.

Now, let’s talk about target voltage. For AGM or some flooded batteries, the target voltage should be between 2.4 to 2.45 volts per cell or 28.8 to 29.4 volts overall. Choosing a charger with the correct target voltage ensures efficient and safe charging.

Don’t forget about safety features. Most chargers offer protection against reverse polarity and overcharging. These safeguards can help prevent damage to your battery and charger.

Lastly, consider the charging speed. Chargers with higher power output typically charge faster, but they may also be more expensive. Weigh the benefits of a quicker charge time against the additional cost. Find the right balance for your needs.

In addition to these, consider the quality and brand of the charger. The quality and brand can significantly impact its performance and longevity.

Also, check customer reviews and ratings for valuable insights into the charger’s performance and reliability.

Look at the warranty and customer support offered by the charger manufacturer. This can be super helpful if you encounter any issues with the charger.

Consider the operating environment for your charger, as it can affect performance. Some chargers are designed to withstand harsh conditions, while others may require a more sedate environment.

Lastly, check for safety certifications like UL, CE, RoHS, etc., which indicate that the charger has been tested and meets certain safety standards.

Remember, the right charger for you will depend on your specific needs and circumstances.

Before You Go…

You have just learned how 24v chargers work. They can charge different types of batteries using a multi-stage charging process. But do you know what kind of battery charger you need for your specific devices and batteries? Not all chargers are created equal. Choosing the wrong one can damage your batteries or reduce their performance.

If you want to avoid this and find out how to select the best charger for your needs, then you need to read my next article: “What Kind of Battery Charger Do I Need?”. I will show you how to compare different chargers. I will also explain what features and specifications to look for. Don’t make the mistake of buying a charger without reading this first.

Frequently Asked Questions

Here’s the FAQs

What is the ideal charging voltage for a 24V lead acid battery?

The recommended charging voltage for a 24V lead acid battery is typically between 28.8 and 29.4 volts. This makes sure that the battery receives enough power to fully charge. It prevents damage to the internal components.

How long does it take to charge a 24V battery?

The charging time for a 24V battery varies. It depends on the battery capacity and the charger’s current output. A 200 Ah Gel battery needs a charger with at least 25 amps. The charging duration depends on the battery’s current state. Always follow the manufacturer’s guidelines for the specific battery and charger. They will tell you the accurate charging time.

Can a 24V charger be used on a 12V battery?

No, using a 24V charger on a 12V battery can cause damage or even a short-circuit. It is essential to match the charger’s voltage with the battery’s voltage. This is necessary for safe and effective charging.

What are the best 24V battery chargers for heavy equipment?

There isn’t a one-size-fits-all answer to this question. The best 24V battery charger depends on the specific heavy equipment. It depends on its battery requirements. It’s essential to consult the equipment manufacturer’s recommendations. Consider factors such as charging speed, safety features, and durability.

How many amps are needed to charge a 24V battery?

The required amperage to charge a 24V battery depends on the battery’s capacity. As a general rule, a charger with higher current output will charge the battery more quickly. Consult the battery manufacturer’s guidelines for the recommended charging current. This will ensure optimal performance and longevity.

What is the minimum voltage of a 24V battery?

The minimum voltage of a 24V battery is the lowest voltage the battery should reach. This maintains its health and performance. Typically, the minimum voltage for a 24V lead acid battery is around 20-22 volts. Discharging the battery below this level can lead to a shorter battery life. It can also cause permanent damage.

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Steve Brown


Steve is a gadget enthusiast who's always been intrigued by batteries. The founder and editor of Battery Chargers Info, he's assembled a group of like-minded experts to cover every facet of portable power His aim is to help you learn more about your favorite gadgets and their batteries so you can maximize both their performance and their life. Follow him on Twitter: @batterycharge1

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