Maybe you have faced this situation: Can I use a 12V charger to charge a 24V battery? How is the charging efficiency? Will it affect the battery’s lifespan and safety? Today’s article is all about this question, and we believe it can help clear up your doubts.

What Is a 12v Charger?

A 12V charger is a device specifically designed for charging 12V batteries. It works with different types of 12V lithium batteries and 12V lead-acid battery systems. Its output voltage is slightly higher than the battery’s rated voltage, usually between 13.8V and 14.6V. This helps push current into the battery more effectively. The output current can range from a few amps to several dozen amps. You can choose the right one based on your battery’s capacity.

We need to remember one important thing: Charging will only work properly and steadily when the charger’s output voltage matches the battery’s rated voltage.

What Is a 24v Battery?

A 24V battery is a battery system with a rated voltage of 24 volts. Common types include lithium batteries (like LiFePO4) and lead-acid batteries. Its full charge voltage is typically around 28V, while the discharge cutoff voltage is about 20V. Compared to 12V batteries, 24V batteries can deliver higher power output and better efficiency, making them suitable for equipment that demands better performance.

Can You Charge a 24v Battery with a 12v Charger?

A 12V charger cannot charge a 24V battery at all, and it may even damage the battery. The reasons are as follows:

  • Not enough voltage: The charger’s voltage must be higher than the battery’s for current to flow in. A 12V charger’s output is much lower than a 24V battery needs, so it can’t charge properly.
  • Battery damage risk: Using a low-voltage charger for long periods will keep the battery constantly undercharged. This deep discharge not only speeds up battery aging and reduces capacity, but can even shorten the battery’s lifespan.
  • Safety risks: In extreme cases, incorrect charging may cause the battery to overheat, swell, or even lead to more serious safety issues.

Is There an Alternative Solution?

If you don’t have a dedicated 24V charger and need an alternative,  You can consider the following options. Note: We recommend these only for experienced users.

Option 1: Connect two 12V chargers in series to get 24V output

Note: This method doesn’t allow precise charging control. Also, you must use two identical chargers and connect them properly – otherwise you could damage either the chargers or the battery.

Option 2: Use a DC-DC boost converter to step up 12V to 24V

Note: The boost module must have constant voltage/current features. Also, this method requires advanced technical skills – it’s better suited for experienced users.

How to Charge 24V Batteries Correctly?

For safe and efficient charging, we strongly recommend getting a charger specifically made for 24V batteries. These chargers provide more accurate voltage and charging patterns, which helps extend battery life and maintain performance. Here’s how to properly charge a 24V battery, we hope you find this helpful:

  • Choose the right charger for your battery type – like lead-acid or lithium batteries. Different chargers have different charging modes to better protect the battery.
  • Use a 24V charger that matches your battery – this ensures it reaches the proper cutoff voltage (28.8V~29.4V).
  • Charge in a well-ventilated area – avoid hot or damp places.
  • Keep an eye on the charging process – watch for overheating.
  • Unplug the charger once the battery is full – don’t leave it connected.
24v 100ah lifepo4 battery Charging methods 02

24v 100ah lifepo4 battery Charging methods 02

Conclusion

We believe you now understand why you cannot use a 12V charger for a 24V battery, and how to properly charge a 24V battery. Getting the right equipment makes charging more efficient and helps your battery last longer.

If you’re looking for a 24V battery manufacturer, contact Delong – we’re one of the best lithium battery manufacturers in China.

FAQ

Can a 12V Charger Slowly Charge a 24V Battery?

No, a 12V charger cannot charge a 24V battery.

If the 24V Battery Is Dead, Can a 12V Charger Be Used in an Emergency?

No, because the voltage does not match.

Can a 24V Charger Charge a 12V Battery?

No. Because a 24V charger’s output is too high, it will also damage a 12V battery.

 

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