Are Milwaukee M12 & M18 Batteries Interchangeable? Breaking Down Brand Compatibility

Replacing flashlight batteries is straightforward, often involving a simple switch with any available AA battery pack. However, the scenario becomes more complex with power tools, especially those in woodworking shops.

This article delves into the compatibility of Milwaukee battery packs, specifically the M12 and M18 variants, with other prominent brands such as Ryobi, Makita, Bosch, Craftsman, Ridgid, Dewalt, and Bauer (Harbor Freight).


No, Milwaukee batteries aren’t interchangeable with other brands. M18 batteries are designed for M18 tools, and M12 batteries are specific to M12 tools. Using Milwaukee batteries in other brands will void the warranty of the battery and tool.

It’s important to note that these power tools operate on lithium-ion batteries, emphasizing the intricacies of brand compatibility and interchangeability.

Milwaukee Batteries

Milwaukee 48-11-1828 Genuine OEM M18 3 Amp Hour 18V Lithium Ion XC Extended Capacity Battery with Redlink Intelligence and Extreme Weather Performance

Milwaukee is a well-known company that manufactures power tools and the batteries that power them. 

It is known for its M12 and M18 power tools in particular.  They are also known for the power, runtime, and speed that exceed many other lithium-ion batteries that power them.

The major difference between these two designations is related to size and weight:

  • CP batteries. These lightweight, compact batteries (CP) run with 5 lithium-ion cells.  They will power both M12 and M18 tools and have a fast charge time, making them a good choice for simple repetitive tasks that require a light power demand and lighter tools.
  • XC batteries. These are a step up with extended capacity (XC) and carry 10 lithium-ion cells.  These, too, are available to power both M12 and M18 tools and offer a longer runtime and power level, suitable for tools that require high performance, like jigsaws, circular saws, and hammer drills.
  • HD batteries. As you might guess, these high-demand (HD) batteries have the most number of lithium-ion cells at 10.  They are intended exclusively for the M18 tools and provide the best performance for high-demand use, such as rotary hammers and chain saws.

These batteries are designed for specific Milwaukee tools and their best performance purposes.  The battery you choose for your M12 and M18 Milwaukee tools.

What Is The Difference Between Milwaukee and Milwaukee Fuel?

On Sale
Milwaukee 48-11-1850 M18 Redlithium 5.0Ah Bat Pack
  • REDLINK Intelligence: Provides optimized performance and overload protection using total system...
  • Fuel gauge onboard: Displays remaining runtime for less downtime on the job
  • M18 red Lithium 5.0Ah Bat pack

We’re back to walking about Milwaukee tools here.  The simple answer to this question has to do with the difference between brushed and brushless motors.

  • Brushed motor. Not to be too technical here, a brushed motor contains a configuration of wound coils that act as a two-pole electromagnet. 
  • Brushless motor. Unlike the brushed motor, the brushless motor uses a permanent magnet as its rotor.

What, you ask?  It’s not important to understand the role magnets play in a motor for the purposes of this question.  It is enough to say that the difference between Milwaukee M18 tools and Milwaukee M18 Fuel tools.

Milwaukee M18 tools are brushed motor tools, and Milwaukee M18 Fuel tools are brushless motor tools.  Milwaukee M18 Fuel tools take advantage of the brushless technology.

Milwaukee 2 PC M18 FUEL Auto Kit - 1/2" Impact Wrench and 3/8" Impact Wrench

All of Milwaukee’s Fuel products are based on advanced innovations, including the Powerstate Brushless motor, RedLithium battery packs, and Redlink Plus hardware and software. 

Brushless motor tools are characterized by reduced maintenance, heat, noise, and improved efficiency.  Brushless motor tools are considered high-end tools and can be relied upon for long-lasting, peak performance in your woodworking shop and on the job site.

Brushless motor tools are also more energy-efficient because no energy is lost by friction from brushes rubbing together; they are also smaller, lighter, and longer-lasting.

Interchangeability of Milwaukee Batteries

This is an easy question to answer.  M18 batteries will not work with M12 tools.  Size and power determine that.  M12 batteries are only compatible with M12 tools, and M18 batteries are only compatible with M18 tools.

You can use any M18 battery with any M18 tool, and the same for M12 batteries and M12 tools.

Do Milwaukee Batteries Work With or Fit Other Brands?

This question has a qualified yes answer. 

For instance, with a Milwaukee to Ryobi One+ 18v Battery Adaptor, you can use your M18 battery with a Ryobi 18v tool. 

There is also battery compatibility between Dewalt and Milwaukee batteries in some instances.  And, Makita 18v batteries will work with Milwaukee 18v tools.

It is important to remember, though, that Milwaukee Fuel batteries are designed to work with brushless motor tools.

Do Milwaukee Batteries Have a Lifetime Warranty?

Do Milwaukee Batteries Have a Lifetime Warranty

While Milwaukee batteries will be replaced or repaired in the event of defective materials or workmanship during assembly, they do not carry a lifetime warranty.  The warranty is for 5 years or 2000 charges, whichever occurs first.  This is measured from the date of purchase, so be sure to keep your proof of purchase.

One additional aspect of the Milwaukee warranty is for the first 1000 charges or 2 years of the warranty when the battery will be replaced free of charge for a defective battery.

Milwaukee tools have shown to be among the most innovative, reliable, and best-performing cordless power tools and battery packs.  The M12 and M18 batteries are designed to be most effective with Milwaukee tools. Keep this in mind when considering both your tools and their batteries.

On Sale
Milwaukee 48-11-1850 M18 Redlithium 5.0Ah Bat Pack
  • REDLINK Intelligence: Provides optimized performance and overload protection using total system...
  • Fuel gauge onboard: Displays remaining runtime for less downtime on the job
  • M18 red Lithium 5.0Ah Bat pack

Last update on 2024-06-14 / Affiliate links / Images from Amazon Product Advertising API