Are DeWalt and Milwaukee Batteries Interchangeable?

DeWalt and Milwaukee are two of the leading power tool brands. Each offers an extensive range of high-quality power tools, along with an array of batteries and chargers to keep your tools charged up and ready to go.

If you’ve already got - or you’re planning to buy - power tools from both DeWalt and Milwaukee, you may have questions about whether the batteries are interchangeable.

The short answer is sometimes, but the recommendation is to match the battery to the manufacturer! This battery compatibility guide will dig deeper into why that’s the case, along with some potential caveats! Here’s what we’ll cover:

• Understanding DeWalt and Milwaukee battery systems
• Compatibility issues
• Attempting to use DeWalt batteries in Milwaukee tools and vice versa
• Adapters and aftermarket solutions
• Manufacturer warranties and policies

Understanding DeWalt and Milwaukee Battery Systems

First, we’ll introduce the battery systems used by each power tool manufacturer.

DeWalt Battery Overview

DeWalt has four cordless power tool systems, all of which are explored in more detail in our guide to whether DeWalt batteries are interchangeable. To summarise:

• DeWalt XR FlexVolt Batteries: These batteries switch automatically between 54V and 18V as required by the tool, offering enough power for jobs that would previously rely on corded tools.
• DeWalt Powerstack Batteries: These batteries offer 50% more power than comparable cylindrical cell batteries and double the lifespan.
• DeWalt XR 18V Batteries: DeWalt’s biggest range, featuring over 250 products suited to hundreds of different applications. The batteries offer up to 5Ah for high runtime.
• DeWalt XR 12V Batteries: These batteries are lightweight, compact, and powerful. They're great for jobs with limited access and offer high levels of versatility.

Milwaukee Battery Overview

Milwaukee has three cordless power tool systems, as follows:

• M18™ 18V Batteries: A system with more than 250 tools with a selection of battery sizes. All M18 tools fit all M18 batteries.
• M12™ 12V Batteries: A system with over 100 tools, all of which are compatible with all M12 REDLITHIUM batteries.
• MX FUEL™: A range of heavy-duty tools and batteries, with full compatibility within the system.

Key Differences Between DeWalt and Milwaukee Batteries

Aside from the obvious difference (Milwaukee tools and batteries are red, DeWalt are yellow), there are some functional differences between the batteries.

• Compatibility: There is no compatibility between Milwaukee battery systems, while DeWalt offers some inter-system compatibility.
• Price point: Milwaukee tools and batteries come in at a slightly higher price point than DeWalt.

Compatibility Issues

If you’ve got Milwaukee and DeWalt tools, you might be tempted to switch the batteries around. This can be a tempting option if you need to use a red tool with a flat battery and have a charged yellow battery handy, but you need to be aware of the issues.

First up, physical fit is the main determinant of whether DeWalt and Milwaukee batteries (or any batteries from different tool brands) are interchangeable. If the battery physically won’t fit in the tool, then you can’t use it.

Battery packs are designed with unique connectors and locking mechanisms, designed partly to hold the battery in place and make sure it provides power, and partly to prevent interchangeability.

You also need to be aware of voltage mismatch. Batteries from different manufacturers (and their different systems) may have different voltages, and using a battery with higher voltage than the tool is rated for can cause potentially irreversible damage to the motor and other components. Voltage mismatch can also cause performance issues, where batteries are unable to provide enough power required for the tool to function correctly.

Next up, battery management systems. Manufacturers use sophisticated systems to monitor performance, reducing the risk of batteries overheating, overcharging, or over-discharging. Using a battery in another manufacturer's tool means it may get too hot, too charged, or too flat - all of which can permanently damage the battery.

If you decide to go for it, there is an increased risk of fire from overheating or electrical shorts. For these reasons, manufacturer warranties are often voided when you use another manufacturer’s battery.

Attempting to Use DeWalt Batteries in Milwaukee Tools and Vice Versa

Search on Google for information about DeWalt and Milwaukee battery interchangeability and you’ll find plenty of discussion where people have tried with varying levels of success to interchange the two. Below we’ve rounded up some of this information.

However please note: the following is given for informational purposes only, and SGS Engineering cannot accept any responsibility for damage to tools if you attempt to interchange batteries. Please refer to manufacturer information.

Using DeWalt Batteries in a Milwaukee Tool

A user from the Milwaukee Tools subreddit discussion gives the following insights:

• DeWalt batteries in a Milwaukee tool will over discharge the DeWalt batteries.
• You’ll have no thermal protection, so stick to low powered tools.

Using Milwaukee Batteries in a DeWalt Tool

The same Reddit user gives the following information about trying things in the opposite direction:

• DeWalt tools will stop working with Milwaukee batteries around 15W.
• You will have no thermal protection here as the DeWalt tool won’t know if the Milwaukee battery has overheated.

Adapters and Aftermarket Solutions

If you’re still keen to try interchanging batteries, you might want to explore adapters and aftermarket solutions. These are third-party products designed to facilitate the use of batteries by other manufacturers in Milwaukee or DeWalt tools.

However, there are risks here too that you need to be aware of:

• Adapters can be unsafe, as there is no way to know whether the manufacturer is reputable, or whether the adapter will work as advertised.
• The connectors in the adapter are unlikely to align perfectly with a tool or battery, meaning increased risk of damage, overheating, or overcharging.
• Manufacturers warranties will more than likely be voided if you use a third-party adapter.
• Service centres may refuse to repair tools that have been used with third-party adapters.

In short, we’d probably advise against this course of action.

Manufacturer Warranties and Policies

While they don’t make for particularly gripping reading, referring to manufacturers' warranties and policies is the best course of action when deciding how to use and power your tools.

These documents are designed to protect you, the user, by guaranteeing that the product will perform as advertised, for the specified warranty period. And, if this is not the case, the warranty provides assurance that it will be repaired or replaced at no additional cost to you.

Using a battery made by anyone other than the manufacturer adds a variable to the equation that the manufacturer has no control over, meaning they can no longer predict how the tool will behave. Therefore, the warranty is voided to protect the manufacturer from liability for problems, damage or injury caused by factors beyond their control.

So, while it might seem tempting to save some money by using another manufacturer’s battery, or even a third-party product, the potential cost of having to replace a damaged tool that’s no longer covered by warranty is likely to be much greater. And that’s not to mention the risk of fire, electrical surges, or other health and safety risks.

DeWalt and Milwaukee Batteries are not Directly Interchangeable

As an owner of Milwaukee and DeWalt tools, you know how it feels to use a high-quality power tool to do a job properly. You’ve obviously put in the research and made an informed purchase as well, so it makes a lot of sense to protect your tools as much as possible by using the right batteries wherever possible. It’s always better to charge a flat matching battery than risk using a charged non-matching one. And it’s always better to buy a new battery made by the same manufacturer than to use another manufacturer’s battery.

If you’ve still got questions about batteries and tool compatibility, whether for Milwaukee, DeWalt or any other tool brand, please feel free to get in touch with our team. We’ll be happy to answer your questions and connect you with the battery and/or tool you need to get your job done.