How to Fix Battery Charger Flashing Red Light?

Normally the normal charger can show different types of lights that blink when charging a battery. The flashing light happens when the battery you are charging turns out to be hotter than the other parts due to the converter circuitry with the chargers that produce heat.

Every charger has a circuitry converter that helps in determining the colour of the flashlight depending on the status of the battery. The major issue of the problem can be with wiring problem, or that it indicates a certain action with your battery that is either full or it is bad.

The article below contains the tables of contents, the reasons for the battery charger flashing red and how to fix them, the frequently asked questions and lastly the conclusion.

How to fix a battery charger flashing the red light

Battery Charger Flashing Red Light

After identifying the issues with the battery charger, you need to find ways of fixing the problems to avoid causing much damage to the charger and the battery and to increase the lifespan of the two items. Consider following the manufacturer’s instructions when working on the two items to avoid causing injuries to the user and the devices. Below are some of the steps to follow when fixing the problems:

Techniques to use for fixing the flashing red light in the charger;

TechniqueFunctionEssential products
Identifying the cause of the red flashing lightCheck the batteries and the charger to know which one has a problem.Battery charger, check Amazon for the best batteries
Check the state of the batteryTo know if the battery is full or not. 
Check if the batteries are deadTo know if they need replacement or  not 
Check the temperatures of the battery using a thermometerTo identify the temperatures since high temperatures are not goodCheck Amazon for the best battery thermometers
Clean the battery and charger end using a piece of cloth or cotton woolTo remove dirt on the battery and charger endsCheck Amazon for the cleaning detergents, cotton wool

i. Identify the issue with the flashing red light on the battery charger

In this step what you need to do is test the batteries with a different charger so that you can know if the issue is with the charger or the battery. If the second charger fails to work, then the issue is with the battery but if the second charger works then the issue is with the charger. Choose to use even three chargers for testing the battery if they are defective or the chargers are defective.

ii. Check if the batteries are fully charged

Consider checking the state of the batteries, since in some cases it will show a flashing red light with the battery chargers to indicate that they are full. That is if they are full then there is no issue with either the battery or the charger that you only need to remove the battery and insert it again to confirm.

iii. Check if the batteries are hot or dead

Hot batteries can cause the charger to flash a red light since the temperatures within them are very high and if they are dead the battery charger will flash a red light.  If the batteries are dead, consider getting new batteries for use with the charger. Otherwise, if the charger is the one with issues, consider consulting for a technician to help you fix the issue if you do not have any idea of how to work with it but if you know more about the charger you can fix it by yourself so long as you follow the manufacturer’s instructions.  Check if the charger has a warranty that you can take it back for replacement.

iv. Check the temperature around the batteries

If you are experiencing high temperatures with your batteries, they can produce the red light with the charger when you insert it. Therefore, consider reducing the temperatures with the battery before you insert it into the charger.

v. Clean the contact area of the battery and charger

Consider cleaning the battery ends and the chargers end so that when they get in touch there could be no issues with the charging process since when the ends of the charger and the battery are dirty, there could be no transmission of power between them and the charger will flash a red light.  Consider using cleaning detergents and a piece of cloth or cotton wool for cleaning.

Why is the battery charger flashing a red light?

Why is the battery charger flashing a red light

The flashing battery charger is an indication of something that is not right for the battery for example the battery is bad. Below are some of the most common problems that cause the battery charger to flash the red light:

  • Indicates the battery is charging

Not every time you see the flashing red light from the battery charger is that there is an issue with either the charger or the battery that should concern you but instead you should consider checking what is happening. It is because when the charger is charging it will always show a red light to show the user that everything is good including the connection.

  • High temperatures

The flashing red light on battery chargers can be a result of the high temperatures the charger is experiencing such that the LED flash will detect and warn the user using the red flash for the high temperatures.

When the battery is charging there is the production of heat which shows that the charger and the batteries are getting warmth from the electricity that is they turn to be hot there could be something wrong with the charger or the batteries that can later lead to an explosion.

  • The battery is full

When the battery is full and you insert the charger, the charger will show a red light that indicates the battery is ready for use and has enough power to run the activities it needs.

However, if you try to remove the batteries from the charger and then insert them again in the charger, the red light will flash after some time to show that the batteries are full that it cannot know the reason you are inserting them again in the charger but it can interpret that it is full and notify the user.

  • The battery is not rechargeable

We use chargers to charge batteries that are rechargeable such that you can charge them and when the power is over, you insert the charger again. Therefore, you can see the red light in this case, if you cannot recharge the battery such that when you insert the charger, the flash red light will blink.

The non-rechargeable batteries will flash the red light with its best moments, that if there is a mess somewhere, it will show a rapture that can cause injuries to the whole system and the user.

  • Use of different brand batteries

Some chargers are not compatible with all types of batteries that when you change the battery the chargers will show that they are not compatible. What you need to do to avoid the issue is to use different batteries with the charger such that you do not limit the charger to a specific battery. However, using different brand batteries for the charger will cause the charger to flash the red light as it cannot charge them.

  • Poor connections between the charger and the battery

The connections between the charger and the battery should be tight so that they can charge without any errors. Therefore, when the chargers’ connection and the battery are loose, the charger will flash a red light when charging to indicate there is no charging taking place and that you need to check the connection. Therefore, when charging the battery ensure you have a tight connection between the two items for proper charging to take place.

  • The battery is flat

When you use the battery and it is flat then you insert it to a charge to charge, there can be a flashing red light since the charger will be straining to charge the battery to have power. Therefore, you should avoid using the battery until it is flat.

  • Defective battery pack

When the charger is flashing a red light and it has no issues with it, consider checking the battery pack as if it is bad, it will cause the issue and it can fail to charge.

Measures to take when using the battery and charger safely

Measures to take when using the battery and charger safely

a. Always check the batteries and replace them if they are dead.

b. Consider cleaning the chargers and the battery’s end before connecting them for the charging process.

c.  Avoid using extension cords and attachments for charging the batteries unless the manufacturers recommend using them.

d. Avoid using batteries from different brand companies that are not compatible with the charger.

e.  Consider using batteries that you can charge them with.

Frequently asked questions;

  • What is the best type of battery to use?

The best type of battery to use is the Duracell battery.


Battery charger flashing red light can be due to several factors that you can easily identify and fix immediately. The guide above contains the things you need to check before fixing the issue which are the probable causes of the flashing red light with the battery charger.

Consider checking on the manufacturer’s instructions on how to use the battery charger and the battery when charging to avoid some upcoming issues. Follow the measures you need to consider when owning both the charger and the battery. If you have any issues with both the devices, choose to replace them before using them. 

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