Quick answer
- A flashing red light on the Makita DC18WA charger typically indicates a fault with the battery or the charger.
- Ensure the charger is plugged into a functioning outlet and that the battery is a compatible Makita G-Series pack (the DC18WA is not compatible with LXT or CXT batteries, per Makita UK).
- A flashing red LED with no battery inserted is not documented as normal operation in the DC18WA manual — it more likely indicates an internal charger fault.
- If the charger works with another battery, the original battery may be defective.
Symptoms
When using the Makita DC18WA charger, you may notice a flashing red LED indicator light. According to the owner's manual, the charge light should be off with no battery inserted, steady red while charging, and off again once charging completes — so a flashing pattern with no battery present is not documented normal behavior and usually points to an internal fault. If you insert a battery and the light continues to flash, it suggests a potential issue with the battery itself or the charger. You may also hear no sounds, as the charger operates quietly during normal function.
Quick checks
- Power Source: Verify that the charger is plugged into a working outlet. A malfunctioning outlet can lead to improper charging behavior.
- Battery Compatibility: Ensure the battery is compatible with the DC18WA. This charger is built for Makita G-Series (14.4V / 18V G-series) batteries and is explicitly not compatible with Makita LXT or CXT Li-ion packs (per Makita UK). An LXT battery won't seat or charge correctly on this unit.
- Temperature Check: If the battery is cold (below 32°F), the charger may not recognize it due to the battery management system (BMS) safety lockout. Allow the battery to warm up to room temperature.
- Visual Inspection: Check the charger and battery for any visible signs of damage, such as corrosion or physical deformities.
- Charger Reset: Unplug the charger for a few minutes and then plug it back in. This can sometimes reset the internal electronics.
Step-by-step fix
-
Remove the Battery: Always start by removing the battery from the charger to ensure safety during troubleshooting.
-
Inspect the Charger: Check the DC18WA charger for any visible damage or debris in the charging port. Clean if necessary.
-
Test with Another Battery: If available, try charging a different Makita G-Series battery. If the charger works with another pack, the original battery may be defective.
-
Check the Outlet: Use a different outlet to eliminate the possibility of an electrical issue. Plug in another device to confirm the outlet is functioning.
-
Monitor Temperature: If the battery is cold, allow it to warm to room temperature before attempting to charge again. This ensures the BMS is not preventing charging.
-
Replace the Battery: If the charger still shows a flashing red light with a known-good G-Series pack, the battery may be at end of life. If you also own tools on Makita's separate 18V LXT platform (different chargers, different batteries), the BL1850B below is a common 5.0Ah LXT replacement — note that it is for LXT chargers/tools and will not work with the DC18WA.
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 charger continues to flash red after following the steps above, consider contacting Makita customer support for warranty assistance. If the charger is still under warranty, you may be eligible for a replacement. Alternatively, take the charger and battery to an authorized service center for further diagnosis and repair.
FAQ
What does a flashing red light mean on the Makita DC18WA charger?
A flashing red light typically indicates a fault. With no battery inserted, the charge light should be off — a flashing LED in that state is not documented in the manual and usually points to an internal charger problem. With a battery inserted, a flashing light commonly indicates a problem with the battery or a compatibility mismatch.
Can I charge a cold battery with the Makita DC18WA charger?
No, if the battery is below 32°F, the BMS will prevent charging. Allow the battery to warm up to room temperature before attempting to charge.
What should I do if my Makita battery won't charge?
First, check the charger and battery compatibility, inspect for damage, and test the charger with another battery. If issues persist, consider replacing the battery or contacting support.
How can I tell if my Makita battery is defective?
If the battery does not charge in a functioning charger and other batteries work fine, the battery may be defective. Look for signs of swelling or corrosion as well.
Is the Makita DC18WA charger compatible with all Makita batteries?
No. The DC18WA is a G-Series charger designed for Makita 14.4V / 18V G-series batteries. It is not compatible with Makita's LXT or CXT Li-ion packs, and it will not work with other battery platforms (per Makita UK).