- Garden
- Cordless garden tools
Green and red blink
Makita Green and red blink on DC18RC charger: charge fault
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
On the Makita DC18RC fast charger, if the charging light flashes alternately in green and red color, charging is not possible. Unplug the charger by pulling the plug, check the charger and battery terminals for dust between 10 °C and 40 °C, and test with another Makita cartridge.
Safety first
Stop and check this first
- To reduce the risk of injury, charge only Makita-type rechargeable batteries (non-rechargeable batteries cannot be charged and other types may burst), do not charge in the presence of flammable liquids or gases, and do not attempt to use a step-up transformer, an engine generator or a DC power receptacle.
- Do not operate or disassemble the DC18RC charger if it has received a sharp blow, been dropped, or has a damaged cord or plug (incorrect reassembly may result in a risk of electric shock or fire), and never short batteries, destroy a battery by fire, or expose the battery or charger to water, rain or snow.
Safe checks you can perform
- Unplug the DC18RC charger and clear dust from the terminals and cooling vents
- Insert the cartridge until it stops on the guide at 10 °C to 40 °C
- Test another Makita rechargeable battery cartridge on the DC18RC charger
Leave these tasks to a qualified professional
- Do not attempt this professional task: Replacement of a worn-out or damaged Makita battery cartridge and battery recycling
- Do not attempt this professional task: DC18RC charger, cooling fan or cord repair by a qualified serviceman or Makita service center
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Replacement of a worn-out or damaged Makita battery cartridge and battery recycling
What they doWhen the terminals are free of dust and the DC18RC charger works normally with other cartridges while one cartridge triggers the alternating green and red blink, that worn-out or damaged cartridge is replaced with a Makita-type rechargeable battery and recycled.
They must show youthe replacement Makita cartridge charging from red to green with the completion melody or long beep.
In writingthe model code of the replacement Makita battery cartridge (such as BL1830B or BL1850B) and recycling intake of the old unit.
DC18RC charger, cooling fan or cord repair by a qualified serviceman or Makita service center
What they doIf the alternating green and red flash persists across clean cartridges, if the yellow warning light flashes frequently due to cooling fan trouble, or if the cord or plug is damaged, a qualified serviceman or Makita authorized service center inspects and repairs the charger.
They must show younormal charging start with the red charging light lit and proper cooling air sound.
In writingthe repair or maintenance findings for the DC18RC charger, cooling system or replaced cord.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Unplug the DC18RC charger and clear dust from the terminals and cooling vents
- Who:
- you, with the charger unplugged from the power source.
- How:
- remove the battery cartridge and unplug the DC18RC charger from the power source by pulling the plug rather than the cord, as required before attempting any maintenance or cleaning. Check that the terminal cover opens on inserting and closes on pulling out the cartridge, and clear any dust clogging the terminals or the cooling vents on the charger and battery.
- Result that matters:
- clean charger and battery terminals and unobstructed cooling vents without disassembling the charger.
- If dust was clogging the terminals and the red charging light now lights up when reinserted:
- dust on the contacts caused the alert.
- If the terminals are clean and the alternating green and red flash continues:
- check the guide seating and room temperature next.
- Evidence to keep:
- a photo of the DC18RC terminal bay and the battery cartridge contacts after cleaning.
Evidence: Makita DC18RC Fast Charger / Cargador rápido Instruction Manual (884676Z996)
Insert the cartridge until it stops on the guide at 10 °C to 40 °C
- Who:
- you, indoors at a room temperature between 10 °C (50 °F) and 40 °C (104 °F).
- How:
- plug the DC18RC battery charger into the proper AC voltage source specified on its nameplate (the charging light will flash in green color repeatedly) in a room not below 10 °C (50 °F) or above 40 °C (104 °F), noting that when battery temperature is under 0 °C (32 °F) charging may not start. Insert the battery cartridge into the charger until it stops adjusting to the guide of the charger.
- Result that matters:
- the red charging light lighting up and charging beginning with the preset brief melody sound.
- If the red charging light stays lit (or the yellow conditioning light lights up):
- charging is proceeding normally.
- If the charging light flashes alternately in green and red again:
- cross-test the charger with another Makita battery cartridge.
- Evidence to keep:
- a note of the room temperature and a short video of the DC18RC lights when the cartridge is inserted.
Evidence: Makita DC18RC Fast Charger / Cargador rápido Instruction Manual (884676Z996)
Test another Makita rechargeable battery cartridge on the DC18RC charger
- Who:
- you, with a second Makita-type rechargeable cartridge listed in the manual.
- How:
- insert another Makita Li-ion battery cartridge from the DC18RC charging table (such as a BL1830B 18 V 3.0 Ah or BL1850B 18 V 5.0 Ah cartridge) into the charger until it stops to see whether the red light turns on and changes from red to green with a melody sound or long beep when finished.
- Result that matters:
- identifying whether the alternating green and red flash follows one worn-out cartridge or stays with the DC18RC charger.
- If the second cartridge charges on solid red and finishes on green (22 min for BL1830B 3.0 Ah; 45 min for BL1850B 5.0 Ah):
- the first cartridge is worn out or damaged.
- If the green and red flash repeats across cartridges or the yellow warning light flashes frequently:
- send the products for repair or maintenance.
- Evidence to keep:
- model numbers of both battery cartridges tested and the light pattern shown for each.
Evidence: Makita DC18RC Fast Charger / Cargador rápido Instruction Manual (884676Z996)
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Garden
- Brand
- Makita
- Product type
- Cordless garden tools
Known code variants
- Cargador Makita DC18RC parpadea verde y rojo
- Charging light flashes alternately in green and red
- DC18RC flashing green and red
- DC18RC parpadeo verde y rojo
- Green and red alternating blink
- Green and red blink
- La luz de carga parpadea alternativamente en color verde y rojo
- Makita batería defectuosa cargador DC18RC
- Makita charger flashing green and red
- Makita DC18RC defective battery light
- Makita luz verde y roja parpadeando
What it means
Makita instruction manual 884676Z996 for the DC18RC Fast Charger pairs the alternating green and red charging light with the defective battery symbol and states that charging is not possible because the terminals on the charger or battery cartridge are clogged with dust, or the battery cartridge is worn out or damaged. Indicator patterns on other Makita chargers may differ, and this blink pattern alone never proves that the charger or battery cartridge is permanently faulty.
Warnings and stop conditions
- Mediumsource verified
To reduce the risk of injury, charge only Makita-type rechargeable batteries (non-rechargeable batteries cannot be charged and other types may burst), do not charge in the presence of flammable liquids or gases, and do not attempt to use a step-up transformer, an engine generator or a DC power receptacle.
Evidence: Makita DC18RC Fast Charger / Cargador rápido Instruction Manual (884676Z996)
- Highsource verified
Do not operate or disassemble the DC18RC charger if it has received a sharp blow, been dropped, or has a damaged cord or plug (incorrect reassembly may result in a risk of electric shock or fire), and never short batteries, destroy a battery by fire, or expose the battery or charger to water, rain or snow.
Evidence: Makita DC18RC Fast Charger / Cargador rápido Instruction Manual (884676Z996)
Symptoms and causes
Probable causes · in order
- Terminals on the DC18RC charger or battery cartridge clogged with dustCommon
In manual 884676Z996 for the DC18RC fast charger, Makita states that when the charging light flashes alternately in green and red color, the terminals on the charger or battery cartridge are clogged with dust.
Evidence: Makita DC18RC Fast Charger / Cargador rápido Instruction Manual (884676Z996)
- Worn-out or damaged Makita rechargeable battery cartridgePossible
Manual 884676Z996 explains that an alternating green and red flash also occurs when the battery cartridge is worn out or damaged and charging is not possible.
Evidence: Makita DC18RC Fast Charger / Cargador rápido Instruction Manual (884676Z996)
Virtual technician
Does Green and red blink still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
Makita DC18RC Fast Charger / Cargador rápido Instruction Manual (884676Z996)
Makita · 2026 · official_doc
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