Are 18v And 20v DeWalt Batteries Interchangeable? (Solved!)

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DeWalt is known worldwide for its wide selection of power tools. Plus, they offer several batteries in the 18v and 20v categories. But are those batteries interchangeable?

Yes, DeWalt’s 18v and 20v are somewhat interchangeable, but minimally. You can use 20v batteries on 18v tools, but not the other way around. The same is true with the chargers for those batteries, as well. All of this is only possible if you have DeWalt’s battery adapter, as the 18v and 20v systems have different connectors.

This guide will unpack everything you need to know about DeWalt’s 18v and 20v systems and where they’re heading in the future.

Let’s get started.

Are 18v And 20v DeWalt Batteries Interchangeable?

Yes, in some cases, DeWalt’s 18v and 20v batteries are interchangeable. But, unfortunately, that’s only true to a very limited extent. The company has not made its tools and batteries universal across the board, so crossing that gap isn’t as straightforward as most people would hope.

Let’s suppose you’d like to enjoy some interchanging between DeWalt batteries and tools. DeWalt has made that somewhat possible, though you’d need first to purchase an additional attachment available only for their 18v tools. 

Unfortunately, the 18v and 20v batteries have very different terminals on them. So, you can’t connect the 20v battery to an 18v tool without the attachment.

At first glance, it can seem a bit confusing as to why DeWalt would make it so difficult to use tools and batteries from within the same brand. However, there are a few crucial things to understand about this brand.

You see, the company is gradually phasing out its lineup of 18v products. They’re doing this to transition towards their more recent 20v batteries and tool models.

As that transition goes on, DeWalt has offered its 18v tool owners a little bit of a lifeline in the form of a neat little adapter.

DeWalt’s Adapter

A lot of tradespeople and regular users grow attached to their tools. So, it’s unlikely that DeWalt users will abandon their 18v tools and replace all of them with newer 20v models.

DeWalt probably understands this, which is why they introduced their 18v to 20v adapter.

Don’t let the name fool you, though. This adapter’s ‘adapting’ only goes one way: it allows you to use newer 20v batteries with older 18v tools.

In a way, DeWalt is extending the usefulness of the 18v tools that people already own. 

Sooner or later, the 18v batteries you might already have will become worn out. Those batteries must be replaced, but what can you do if DeWalt doesn’t make 18v batteries anymore?

The only solution for when that day comes is to buy a new 20v battery and use the adapter to plug it into your 18v DeWalt tool.

Charger Limitations

Unfortunately, the one-way interchangeability above isn’t limited to batteries and tools. Even the chargers are also experiencing the same transition away from 18v towards 20v.

Simply put, users can only use 20v chargers moving forward. The 18v and 20v batteries are compatible with 20v chargers, but not the other way around.

In other words, no, you cannot charge the newer 20v batteries using the older 18v charger that you might already own.

Even in the standard adapter kit sold by DeWalt, the charger they include is their 20v charger. Plus, the adapter will not fit into DeWalt’s 18v chargers, to begin with.

Other Compatibility Issues

Still, there’s another crucial thing that you must be aware of. Earlier, we mentioned that DeWalt allows for limited interchangeability between their 18v and 20v systems.

Well, even with the adapter kit, you can expect to face a lot of compatibility limitations.

For example, the adapter kit cannot combine its premium 20v batteries with compact drills. Plus, several other DeWalt batteries won’t work with this setup either.

So, before you invest in the standalone adapter or the complete adapter kit, be sure to do your homework. You don’t want to end up with an adapter kit that you can’t use with your existing DeWalt tools!

DeWalt Doesn’t Make 18v Tools Anymore

The situation of DeWalt phasing out their 18v tools isn’t just a rumor among tradespeople and DIY-ers anymore. In September 2021, the company released a press statement stating that they were no longer making their 18v batteries in crystal clear terms.

According to DeWalt, they’ll still have enough supply of those batteries until March of 2022. So, perhaps you can get your hands on them to power your 18v tools before then.

But let’s suppose you’re the kind of user who keeps their tools around for decades or longer. Well, you can still do that. But with this news from DeWalt, you’ll eventually have to upgrade to the 20v battery and adapter to keep your tools going.

18v and 20v DeWalt Batteries; What’s The Difference?

Long before the news came out that DeWalt was phasing out their 18v batteries, both of these options were readily available for consumers to buy. Even back then, the debate of which one was better than the other split DeWalt fans down the middle.

No matter which side you were on, there were plenty of other Dewalt users who would swear that you were wrong.

Some believed that DeWalt’s 20v system was superior, while others defended the 18v for being more efficient.

But here’s the funny part: 18v batteries and 20v batteries are exactly the same on the inside. So what’s the big deal here?

Well, it’s all about nominal and maximum voltage ratings.

Nominal vs Maximum Voltage Ratings

There are two ways you can express a battery’s maximum capacity: their nominal and maximum voltage ratings.

With that in mind, here’s why both 18v and 20v DeWalt batteries are actually the same:

  • Nominal voltage rating: Both 18v and 20v batteries have 5 cells with a nominal rating of 3.6v each. So when you add them together, you get a nominal value of 18v.
  • Maximum voltage rating: Both 18v and 20v batteries have 5 cells with a maximum rating of 4v each. So when you add them together, you get a maximum value of 20v.

So, in reality, the 18v and 20v batteries are exactly the same on the inside. At first glance, the only difference seems to be the method they choose to express the batteries’ voltages. 

Other Differences

To be fair, there have always been a few other differences between DeWalt’s 18v and 20v batteries.

The most evident difference, and likely the first one you’ll notice, is the connector. The 18v and 20v DeWalt batteries have very different connectors that prevent them from being used directly with both systems.

That’s why the adapter is an absolute necessity if you want to use 20v batteries on 18v tools.

Besides that, the different connectors also prevent the 18v or 20v chargers from being used interchangeably.

Final Thoughts

Through this guide, we’ve seen some interchangeability between DeWalt’s 18v and 20v systems. But, unfortunately, it only goes one way: you can use 20v batteries in 18v tools, but only with the required adapter.

But is that interchangeability worth it? Well, if you’re not ready to give up your 18v DeWalt tools, then yes. But, on the other hand, using the adapter will keep those tools helpful to you for a very long time.

However, if you’re in the market for an upgrade, or if this is your first time buying DeWalt tools, you’d be better off investing in the 20v system moving forward.

One response to “Are 18v And 20v DeWalt Batteries Interchangeable? (Solved!)”

  1. […] instance, if you have a DeWalt Power drill and it requires a 20v battery, your options are buying a DeWalt 20v battery or something off of […]

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