After a day of manual labor, you are ready for some rest; you slip off into dreamland before there’s time to unplug the fully charged battery. Does it hurt to leave a Milwaukee battery on the charger all night?

You can leave a Milwaukee battery on charge; however, it’s not recommended. Doing so occasionally will not damage it, but over-charging can break the cells down more quickly. 

For more information about charging a Milwaukee battery and other helpful information to extend its life, continue reading. 

Will Charging a Still Charged Milwaukee Battery Hurt It?

There are a lot of different opinions regarding how to charge and store power tool batteries. You are likely to get a different answer regardless of who you ask but when it comes to charging a Milwaukee Lithium-Ion battery here’s what you need to know.

Milwaukee claims that their batteries do not create a block as many other styles of battery are said to. This means that you are able to work for a little while and charge the battery even if it is not fully dead.

Let’s find out why you should be cautious doing this with other brand batteries.

Why You Should Be Cautious Charging an Already Charged Battery

Milwaukee Lithium-Ion batteries are designed to prevent this from happening, but other brands not so much.

In the past charging a power tool battery before it was fully dead would cause the battery to run down faster, requiring even more charging. 

Even though these high-tech power tool batteries are designed to stay on a charger or be charged before they are not dead there are still things to keep in mind so you can be sure it lasts as long as possible.

Continue reading for tips on preserving the life of your Milwaukee battery and tools. 

The Do’s and Don’ts for Charging a Milwaukee Battery

The section below gives you the information you need to know about properly charging your Milwaukee battery as well as tips for doing so safely and making it last as long as possible. 

How Long to Charge Your Milwaukee Battery

The length of time it takes to charge your Milwaukee battery depends upon the size of the battery however it will be in the range of 30 -75 minutes. 

If you are using the M12 battery you can expect a charge time closer to the 30 – 45 minute range. If you opt for more power with the M18 expect to wait closer to an hour for a full charge. 

So essentially in a little more than an hour, you can be up and running again. If you find yourself in the scenario described above don’t worry. 

Falling asleep once in a while won’t kill your battery, however as stated, making a habit of overcharging it can lead to the cells breaking down too soon. 

Do your best to unplug the charger from the wall and the battery from the charger in a timely manner to preserve its life. 

Safe Charging and Storage Prevents Fires and Damage

When charging your Milwaukee battery there are some safety tips to keep in mind to prevent accidental fires or overcharging. 

They include:

  • Keep the charger in a well-ventilated when plugged in and in use; poor ventilation can lead to overheating of the charging unit and possible fire
  • Use the proper charger; using the wrong charger can fault the battery or cause a fire
  • Don’t try to modify the battery to make it more powerful
  • Avoid using extension cords but if you have to, be sure it is 16g or larger to prevent fires

Now, let’s see the next plan of action.

Cleanliness Makes the Connection Last 

Keeping your power tools, batteries, and accessories clean and free of debris like dirt or sawdust will ensure that your battery is getting the proper connection and make your equipment last longer. 

Proper Storage Extends Life of Tools and Batteries

To be sure your Milwaukee batteries last as long as possible it is important to store them in a cool, dry area. 

Avoid moist or damp areas as that can cause corrosion. Areas that are too hot or too cold should be avoided as well. 


Now you know that it’s not the end of the world if you get busy or fall asleep and accidentally leave your Milwaukee battery on the charger. 

Just try not to do it too often. By following the manufacturer’s recommendations for proper charging and storage you will get many more hours of work accomplished.