DeWalt or Makita Battery Won't Charge? Here's What to Check

You've stuck your DeWalt or Makita battery on the charger and nothing's happening. No lights, no charging, nothing. Or maybe it starts charging then stops. Before you chuck it and buy a new one, let's figure out what's actually wrong.

The Battery Is Too Hot or Too Cold

This is the most common reason for a battery refusing to charge, and it's not a fault - it's a safety feature.

Lithium batteries won't accept a charge if they're:

• Below about 5°C (just been in a freezing van overnight)
• Above about 40°C (just been hammered hard on a job)

The charger's protecting the battery cells from damage. Leave it somewhere room temperature for 20-30 minutes and try again. If you've been running it hard, that hot battery needs to cool down before it'll charge.

Dirty Contacts

Look at the metal contacts on your battery and on the charger. See any gunk, dust, or corrosion? That stuff blocks the electrical connection.

Clean both sets of contacts with a dry cloth. If there's corrosion (whitish or greenish buildup), use a pencil eraser or fine sandpaper to clean it off. Don't use anything wet - you don't want moisture in there.

The Battery Has Gone Into Protection Mode

Modern DeWalt and Makita batteries have built-in protection circuits. If the battery's been over-discharged (run completely flat and left that way), it might have shut itself down to prevent cell damage.

Some chargers can "wake up" a sleeping battery by giving it a trickle charge first. Others won't even recognise it. If your battery sat flat for months, this might be the issue.

Try this: Leave it on the charger for an hour even if nothing seems to be happening. Some chargers will slowly bring a protected battery back to life. If nothing after an hour, it might be dead for good.

One Bad Cell

Battery packs contain multiple cells wired together. If one cell fails, the whole pack can stop working. This is especially common in older batteries or ones that have been dropped hard.

Signs of a bad cell:

• Battery worked fine then suddenly stopped
• Charges to "full" but dies almost immediately
• Gets unusually hot during charging

Cell replacement is possible if you know what you're doing (or know someone who does), but often it's not worth the hassle compared to just buying a new battery.

The Charger Is the Problem

Before blaming the battery, try it in a different charger if you have access to one. Chargers can fail too.

Signs the charger is faulty:

• No lights come on at all when plugged in
• Other batteries also won't charge in it
• Makes unusual noises or smells
• LED indicators behave strangely

If you've got a multimeter, check the charger's output voltage. No output = dead charger.

Battery Has Reached End of Life

Lithium batteries don't last forever. After 500-1000 charge cycles (depending on how they've been treated), they lose capacity and eventually die.

If your battery:

• Has been in daily use for 3-5 years
• Has been through hundreds of charges
• Has been left flat for extended periods
• Has been stored in hot environments

...it might just be worn out. That's life. The good news is replacement batteries are available and a new battery in an old tool is still cheaper than a new tool.

What the Charger Lights Mean

DeWalt chargers:

• Red flashing = charging
• Red steady = charged or problem
• Yellow flashing = too hot or cold, waiting
• No lights = no connection or dead charger

Makita chargers:

• Lights climbing = charging (more lights = more charge)
• All lights steady = fully charged
• Flashing = problem or temperature issue

Check your specific charger manual - patterns vary between models.

Prevention for the Future

Make your batteries last longer:

• Don't leave them completely flat for weeks
• Store at room temperature, not in a freezing or baking van
• Don't leave them on the charger permanently
• Keep contacts clean
• Charge before they're completely dead rather than running them to zero