Start with the simplest fixes first
Most DeWalt batteries stop working because of a loose connection, dirt on the contacts, or a charger that needs resetting—not because the battery itself is dead. Before you replace anything, clean the metal contacts on both the battery and charger with a dry cloth or pencil eraser, check that the battery clicks fully into the charger, and try a different outlet. If your charger has a reset button (usually red), press it and wait 30 seconds before plugging in again.
If the battery still won't charge after these steps, move to the next section. Most of the time one of the fixes below will get your battery working again.
Key Takeaways
- Clean the metal contacts on the battery and charger with a dry cloth or pencil eraser, since dirt and corrosion block the electrical connection.
- Press the reset button on your charger (if it has one) and wait 30 seconds, then try charging in a different outlet to rule out power problems.
- Check the battery's temperature—most DeWalt chargers will not charge a battery that is too hot or too cold, and will resume once it reaches room temperature.
- If the battery charges but dies quickly, the cells inside may be worn out and the battery cannot be repaired, only replaced.
- DeWalt batteries have a three-year warranty from the date of purchase, and you can contact DeWalt support with your receipt to discuss replacement options.
Check the battery temperature and let it cool or warm up
DeWalt chargers have built-in safety features that stop charging if the battery is too hot or too cold. If you just finished using the tool, set the battery on a shelf at room temperature for 15 to 30 minutes before trying to charge it again. The charger will usually show a blinking light while it waits for the battery to reach the right temperature.
If you left the battery in a cold garage or car, bring it inside and let it sit for at least an hour before charging. Cold batteries charge slowly even after they warm up, so do not be surprised if the first charge takes longer than usual. Once the battery reaches room temperature, the charger should resume normally.
Clean the metal contacts on the battery and charger
The metal contacts on the bottom of the battery and inside the charger can collect dust, sawdust, or corrosion that blocks the electrical connection. This is the most common reason a battery will not charge, and it takes less than two minutes to fix.
Unplug the charger and remove the battery. Use a dry cloth, pencil eraser, or fine-grit sandpaper (220-grit or higher) to gently rub the metal contacts on the bottom of the battery until they shine. Wipe away any dust with a clean, dry cloth. For the charger contacts, use a dry cloth or eraser to clean the metal points inside the charging slot. Do not use water or cleaning solution—moisture can damage the charger. Once both sets of contacts are clean and dry, insert the battery and plug in the charger.
Reset the charger and try a different power outlet
Many DeWalt chargers have a reset button, usually red or black, on the back or bottom. Unplug the charger from the wall, press and hold the reset button for 30 seconds, then plug it back in. Wait another 30 seconds before inserting the battery. This clears any error the charger may have stored.
If the charger still does not work, try plugging it into a different outlet in another room. A tripped circuit breaker or a faulty outlet can prevent the charger from getting power. If the battery charges in the new outlet, the problem is with your electrical outlet, not the charger or battery. If it still does not charge, move to the next step.
Test the battery in a different charger if you have one
If you own more than one DeWalt charger, try charging the battery in the other one. This tells you whether the problem is the battery or the charger. If the battery charges in the second charger, your original charger is faulty and may need to be replaced. If the battery still will not charge in any charger, the battery itself has a problem.
You can also ask a friend or neighbor with DeWalt tools if you can test your battery in their charger for a few minutes. This is a quick way to narrow down the cause without buying anything new.
Understand when a battery cannot be repaired
If the battery charges but only holds power for a few minutes, or if it will not charge in any charger after you have cleaned the contacts and reset the charger, the battery cells inside are likely worn out. Lithium-ion batteries degrade over time and after many charge cycles, and once they stop holding a charge, they cannot be repaired—only replaced.
A battery that charges but drains quickly is especially common if the battery is more than three years old, has been charged hundreds of times, or was exposed to extreme heat or cold. This is normal wear and tear, not a defect you can fix at home.
Contact DeWalt or buy a replacement battery
DeWalt batteries come with a three-year warranty from the date of purchase. If your battery is still within that window and you have the receipt, you can contact DeWalt customer service through their website or the phone number on your charger to discuss a replacement. Have your receipt and the model number of the battery ready.
If the warranty has expired or you do not have the receipt, you will need to buy a new battery. DeWalt sells replacement batteries in the same voltage as your charger (usually 18V, 20V, or 60V). Buy the same voltage and amp-hour rating as your original battery so it works with your existing charger. Batteries are sold at hardware stores, home improvement centers, and online retailers.
Frequently Asked Questions
Why does my DeWalt charger show a blinking light?
A blinking light usually means the battery is too hot or too cold to charge safely. Let the battery sit at room temperature for 15 to 30 minutes and try again. If the light keeps blinking after the battery has warmed up, clean the contacts on both the battery and charger with a dry cloth.
Can I use a DeWalt battery from an older tool with a newer charger?
Only if they are the same voltage. An 18V battery will not work with a 20V charger, even if they are both DeWalt. Check the voltage printed on the side of the battery and the label on the charger. Mixing voltages can damage both the battery and charger.
Is it safe to leave a DeWalt battery in the charger overnight?
Yes. DeWalt chargers have automatic shutoff features that stop charging once the battery is full, so leaving it plugged in overnight will not damage the battery or charger. However, you should not leave a battery in a hot car or direct sunlight for long periods.
What should I do with an old DeWalt battery that will not charge?
Do not throw it in the trash. Lithium-ion batteries are recyclable and many hardware stores and recycling centers accept them for free. Call ahead to confirm, or search for a battery recycling program in your area online.
How long does a DeWalt battery usually last before it needs replacing?
Most DeWalt batteries last between 300 and 1,000 charge cycles, depending on how often you use the tool and how you store the battery. A battery used daily might need replacing after one to two years, while one used occasionally could last three to five years.