Makita Battery Won't Charge Flashing Red — What the LED Code Means

Quick answer

• If your Makita battery is showing a flashing red light, it indicates a fault condition.
• First, check if the battery is too hot or too cold, as this can trigger a thermal lockout.
• Ensure the battery and charger are clean and free of debris, which can interfere with charging.
• If the LED pattern persists, consider replacing the battery or seeking professional service.

Symptoms

When your Makita battery won't charge and displays a flashing red light, you may observe the following behaviors:

• The charger LED will blink red, indicating a fault condition. This pattern can vary based on the charger model, but it generally signifies that the battery is not charging correctly.
• You might hear no sound from the charger, as it will not engage if it detects a fault.
• If you attempt to use the battery in a tool, it may not power on or may show reduced performance.

Quick checks

Before diving into deeper troubleshooting, verify these key points:

1. Temperature Check: Ensure the battery is within Makita's published charging range. Per the DC18RC, DC18RD, and DC18RF manuals: 50°F to 104°F (10°C to 40°C). Below 32°F (0°C) charging may not start at all. This is a stricter limit than the generic 32°F Li-Ion floor.
2. Charger Compatibility: Confirm you are using the correct Makita charger for your battery model. For example, the DC18RC and DC18RF chargers are designed for the Makita 18V LXT platform.
3. Battery Condition: Inspect the battery for any visible damage, such as swelling or corrosion. Damaged batteries should never be used and should be recycled properly.
4. Charger Condition: Check the charger for any signs of damage or wear. A malfunctioning charger can prevent the battery from charging.
5. Connection Check: Ensure that the battery terminals are clean and free of debris. Dirt or corrosion can impede electrical contact.

Step-by-step fix

1. Remove the Battery: Always start by removing the battery from the charger or tool to ensure safety during troubleshooting.
2. Inspect the Battery: Look for any signs of physical damage, such as swelling or corrosion. If found, recycle the battery and replace it.
3. Check Temperature: If the battery feels hot, allow it to cool for at least 30 minutes before attempting to charge it again. If it's cold, warm it to room temperature before charging.
4. Clean the Contacts: Use a soft cloth to clean the battery terminals and charger contacts. This ensures good electrical connection and can resolve charging issues.
5. Test the Charger: If you have access to another compatible Makita battery, try charging it in the same charger. If it charges successfully, the original battery may be faulty. If not, the charger may need replacement.
6. Replace the Battery: If the battery continues to show a flashing red light after all checks and cleaning, consider replacing it. A new battery, such as the Makita 18V LXT 5.0Ah Battery (BL1850B), may resolve the issue.

View Makita 18V LXT 5.0Ah Battery (BL1850B) on Amazon (paid link)
View Makita 18V LXT 5.0Ah Battery (BL1850B) on Home Depot (paid link)

If it still isn't working

If the battery still won't charge after following the above steps, consider the following options:

• Warranty Service: Check if your battery is still under warranty. Makita typically offers a 3-year warranty on batteries, which may cover defects.
• Professional Repair: Visit an authorized Makita service center for further diagnostics and potential repairs.
• Replacement: If the battery is out of warranty and not functioning, it may be time to purchase a new battery.

FAQ

Why is my Makita battery flashing red?
A flashing red light indicates a fault condition, often due to temperature issues or battery damage. Check the battery's condition and temperature.

Can I charge my battery if it's cold?
Per Makita's verified DC18RC/DC18RD/DC18RF manuals, the published charging range is 50°F to 104°F (10°C to 40°C). Below 32°F (0°C), the manuals explicitly state charging may not start. Warm the pack to room temperature before charging.

What should I do if my charger is not working?
Test the charger with a different compatible battery. If it doesn't charge another battery, the charger may be defective and require replacement.

How can I maintain my Makita battery?
Keep the battery clean, store it in a cool, dry place, and avoid exposing it to extreme temperatures. Regularly check for signs of wear or damage.

Is it safe to use a damaged battery?
No, using a damaged battery can be dangerous. Always recycle damaged batteries and replace them with new ones.