Can You Use DeWalt Flexvolt Batteries On 20V Tools?

The vast majority of DeWalt's power tool offerings these days run on battery power. The brand has been largely cordless for some time now, embracing a few different battery types to keep its tools going. The similar DeWalt 20-volt Max and 20-volt Max XR are two of its most prominent types, alongside those in the DeWalt Flexvolt line. As the name implies, this series of batteries is designed for flexibility while on the job. That means that they can be used in a range of tools, including those that require vastly different levels of power.

DeWalt's Flexvolt batteries have some kick to them, managing to power the brand's 60-volt tools with ease. Of course, that's not to say that they can't dial things back a bit should you need them to. The "flex" in Flexvolt means they can adjust accordingly, functioning just as well in your 20V DeWalt tools as your 60V ones. You don't need to lift a finger beyond inserting the battery into the tool either, as the switch between voltage levels is done automatically. These batteries will last you while on the job, too, with them coming in 6Ah, 9Ah, 12Ah, and 15Ah varieties at the time of this writing.

While it may sound like the Flexvolt system is pretty perfect, it does have a drawback. The issue isn't so much with batteries as it is with the Flexvolt-branded tools.

Given their ability to reach up to 60 volts, it only makes sense that specific tools are advertised alongside and sold with DeWalt Flexvolt batteries. These tend to be heavier-duty ones, such as 60V brushless chainsaws, rotary hammer drills, and similar pieces in need of such power. While the tools likely meet the needs of those using them, they do have a hidden negative to them that users have taken notice of. Unlike Flexvolt batteries, which can work in standard 20V and 60V tools, standard 20V batteries don't work with 60V Flexvolt tools. In fact, the design of these tools prevents such a connection from happening — something that has led to some chatter online.

"Flexvolt can only accept Flexvolt batteries. The tools have tabs on the battery slot to prevent 20v batteries from being used," explained Redditor u/panther-eagle4 in a thread on this compatibility issue. Others in the thread expressed frustration and confusion over this aspect of Flexvolt tools, but some were quick to explain why this is the case — and it's not due to DeWalt trying to get folks to buy all-new tools and batteries. Simply put, a 20V battery lacks the capability to power a 60V tool, and Flexvolt tools can't adjust to lower voltages. That ability stems solely from Flexvolt batteries. Thus, you'll need 60V or Flexvolt batteries to get your 60V Flexvolt tools running.

With all of that said, DeWalt does have a line of Flexvolt tools that work with 20V batteries. They reside in another subset of tools that's worth discussing in the Flexvolt tool and battery-swapping conversation.

Naturally, DeWalt didn't situate itself into the lineup of the major power tool brands on the market without innovation. This continuous attempt at improvement led to the Flexvolt line in the first place, and, as established, it's not perfect. As great as the batteries are at powering 20-volt and 60-volt tools alike, the tools needed some progress in the backward compatibility department. As a result, DeWalt went back to the drawing board. The brand now offers the masses the Flexvolt Advantage assortment, so folks can get some use out of their 20V batteries — those with and without Flexvolt technology.

The Flexvolt Advantage line consists of 20V tools that get the most out of Flexvolt batteries, increasing power dramatically compared to when standard 20V batteries are in use. Still, while it's recommended that tools with Flexvolt Advantage technology are used with Flexvolt batteries, they are indeed compatible with regular 20V batteries, making them pretty versatile. The only downside is that the Flexvolt Advantage tool lineup is pretty limited at the time of this writing. So, if you're looking to make the swap so you can get the most out of your tools and batteries, you have some waiting to do until your full DeWalt arsenal is equipped with Flexvolt Advantage tech.

The DeWalt tool and battery systems and their compatibility can get a bit convoluted, not to mention that some non-DeWalt tools work with DeWalt batteries. Hopefully, the brand will streamline things a bit more in the future to further allow users more swapping between their tools and batteries.