Can I Use A DEWALT XR Battery in 20v Tools?

We all look for angles to work to our advantage, both in life and in the woodworking shop.  We say that in the better sense of the words, too.  This is especially so, though, in the world of marketing and advertising.  How can we phrase something that makes it seem special or better, or more desirable?

Key Points:

  • DEWALT XR batteries are for use with tools that have a brushless motor
  • They are more compact than other battery packs and carry longer-lasting power at 5ah capacity
  • They are, of course, compatible with DEWALT 20v and 18v XR cordless power tools

To an extent, this is what goes on in the world of cordless tool battery packs.  An example of this is the marketing of 20v tools and the batteries to be used with them.  It is highly probable that most of us have 18v cordless power tools in our woodworking shop.  The prospect of getting a little extra juice to power them might seem appealing, but is it real?

We’ve written of this in past articles, most recently on the difference between an 18v and 20v drills.  Some of these concepts are applicable to today’s topic and this article.

Lithium-Ion Batteries

Lithium-Ion battery technology, fairly new in the industry, replaced nickel-cadmium batteries that were used to power our cordless tools.  

They are easy to charge, have a 3 – 5 year lifespan, and contain cells that range from 1.2 volts to 1.5 volts to 3.6 volts.  Groups of 5 such cells are connected and wired in a series, and every group of 5 cells is wired in parallel to ensure the battery will have a good number of amp hours and watt hours.  This is how a battery pack is able to maintain a constant level of power for our tools, at least until it is time to recharge it.

Each power tool manufacturer makes their own battery packs, sourcing these cells from third parties.  They design their battery packs to work only with their own family of power tools, and in almost every instance, the battery packs are not interchangeable with another brand’s power tools.

We say “in almost every instance” because there are adapters (which we advise against using) to allow some compatibility, as well as physical modifications to a battery pack to make it fit with another brand’s power tools (which we also advise against doing).

Lithium Ion Battery Cells

As we noted, cells come in voltage ratings of 1.2v, 1.5v, and 3.6v.  Mixing and matching these voltage ratings gives us the total voltage of the battery pack as it is assembled.  Five cells each of 3.6v adds up to 18 volts, and it’s likely we all have an 18v battery pack to power our 18v cordless power tools.  

As we have noted in past writing on the subject of battery packs, it’s important to understand what a brand means when it refers to its battery packs as 20v MAX batteries.  When we see a listing for a 20v MAX battery, we ask ourselves if we can use it safely with our 18v tool.  What does that 20v MAX rating actually mean?

It’s the difference between an “on paper” rating and an “actual” rating.  In the “on-paper” world, each 3.6v battery cell has a maximum voltage output, which represents its full potential, of 4 volts.  With a group of 5 cells, that adds up to 20 volts.  In other words, when it’s simply running the tool, the maximum voltage output (power) is 20 volts; but that changes the moment we actually start doing something with it – something like drilling, driving a screw, etc. 

Then, the real voltage output is 18v.  The math tells us this:  5 x 3.6v = 18v.  This is called the battery pack’s nominal voltage.  The initial battery voltage, simply turning the drill on, is 20v; the actual, or nominal, voltage is the 18v we use to power our 18v cordless power tools – drills, circular saws, etc.

DEWALT Battery Packs

It is the DEWALT brand that markets the 20v MAX battery packs to go with its cordless power tools.  It also offers other batteries for its cordless power tools.  Information supplied from the DEWALT website includes:

  • 20V MAX battery packs are for its brushed motor power tools and followed by its 18v battery packs
  • 20V XR battery packs use enhanced component parts in them; according to DEWALT are more compact battery packs and made specifically for their brushless motors.  The XR designation refers to what DEWALT stands for, “eXtreme Runtime, and claims the XR battery packs will last longer than non-XR battery packs.  If a DEWALT tool has an XR stamp on it, that means the tool has a brushless motor.  Brushless motors tend to control energy transfer (battery to tool) more efficiently, and DEWALT claims this allows a user to do more with the same amount of charge.

There is another DEWALT battery pack designation, ATOMIC, but we will save that for another article.

Brushed vs Brushless Motors for Power Tools

While this, too, might be better addressed in another article devoted specifically to the subject, there is a difference between the two types of motors used in power tools.  The difference may or may not be important to you, and it depends on the projects you most often undertake in your woodworking shop.

Basically, the difference goes as follows:  brushed motors have coils in their centers, and these coils rotate around magnets that are a permanent part of the motor, and brushless motors have no such coils, instead having a permanent magnet in their centers that rotate around the coils.

Brushless motors will have a higher degree of efficiency in their performance.  Because of the difference in what moves around (coils or magnets), there is a lower chance of mechanical wear and tear.  They are more expensive to manufacture, and this increases the cost to consumers for power tools that have a brushless motor.

What does that mean for you and me?  If our shop work is on more serious projects that involve the use of cordless power drills, for instance, a brushless version would make a lot of sense.  You’ll get higher speeds and more power and likely require less maintenance.  A piker who engages in more simple and occasional projects probably wouldn’t notice the difference.

Battery Compatibility in the 20V Power Tool Line

DEWALT 20V Max Cordless Drill / Driver Kit, Compact, 1/2-Inch (DCD771C2), Yellow

We know that battery compatibility depends on the voltage.  This means both the battery and the power tool must operate on the same voltage.

DEWALT XR battery packs are 5.0 amp hour lithium-ion battery packs (5ah battery).  The 5ah battery will give you a longer-lasting experience and more bang for the buck, even though you pay more bucks for the battery and the brushless motor-powered tools to use it with than brushed tools.

The important thing, though, is that they are compatible with the entire line of 20v MAX tools.  As we wrote earlier, we also know that 20v MAX tools have a nominal voltage of 18v, and the DEWALT XR batteries are compatible with the DEWALT line of 18v XR tools, also.  

A Video Point Of View on the DEWALT 20v MAX XR Battery

It’s a quick video, about 1 minute, but you’ll get to see an XR battery.  Notice its size, too, in the hand of the videographer and on the power drill.  

The short answer to the question is yes, you can use the XR battery with 20v tools. You now understand what that really means – some of it is marketing and advertisement-speak, and some of it is a real-world application with longer-lasting battery power, according to the DEWALT claims.  

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