As you might know, the difference between Dewalt 20V Max and 18V is essentially marketing in nature, rather than relating to electrical power. There is no functional difference between 20V Max and 18V!
18V is the nominal voltage for 5x 3.6V Li-ion batteries connected in series. 20V Max takes into account 5x 4.0V, which is the average maximum voltage at full charge with no load applied.
In other words, if you have a Dewalt 20V Max 5Ah battery from the USA and a Dewalt 18V XR 5Ah battery from Europe, they are – for all intents and purposes – the same exact battery but with different labels.
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Cover the labels, and you shouldn’t be able to tell the batteries apart.
If there’s no difference where did “20V Max” come from, and why?
More than 11.5 years ago, back in June 2011, Dewalt announced their then-new 20V Max cordless power tool system.
At the time, Dewalt said there were still 63 million 18V stem-style batteries still in the field, and that they would continue to support the 18V platform for a long time. (10 years later, in September 2021, Dewalt finally discontinued their 18V cordless power tool system.)
Dewalt marketing representatives emphasized that, in order to avoid confusing customers and tool users, “20V Max” would create distinction between their 18V primarily NiCad-based cordless power tool system, and the modern line centered on the new slide-style battery
“20V Max” comes from the maximum off-the-charger voltage, with 18V being the battery packs’ nominal voltage.
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One year earlier, in June 2010, Dewalt launched their 12V Max cordless power tool system. Dewalt was not the first brand to use such nomenclature.
Bosch switched over from 10.8V to 12V Max starting in mid-2008, with their second generation PS20 cordless Pocket Driver.
From a Bosch July 2008 press release:
The new [12V Max] terminology, which replaces 10.8V, is meant to reduce confusion in the marketplace by clearly identifying tools that are rated at maximum voltage (i.e. 12V) rather than nominal voltage (i.e. 10.8V) by using the “Max” designator.
Makita launched their first 12V Max cordless power tools in late 2010, converting over from 10.8V as Bosch had done.
From Makita’s November 2010 press release:
The change to “12V max” is consistent with lithium-ion battery voltage ratings that have been adopted in the marketplace since Makita first launched 10.8V Lithium-Ion products in 2008.
Here’s a summary in chronological order
2006 May: Bosch announced 10.8V PS20 Pocket Driver
2007 October: Milwaukee announced a “12-Volt Sub-Compact driver” (2401-22)
2008 July: Bosch switches to 12V Max terminology
2008 July: Makita announces first 10.8V tools
2008 October: Milwaukee announced M12 Hackzall (2420-22)
2010 June: Dewalt announces 12V Max cordless power tool system
2010 November: Makita switches to 12V Max terminology
2011 June: Dewalt announces 20V Max cordless power tool system
With 12V Max already adopted in the USA by Bosch, Makita, and Dewalt, the plan for Dewalt to go with 20V Max for their new 18V-class Li-ion cordless system made perfect sense.
However, “20V Max” was only in use in North America. In Europe and elsewhere, the new cordless lineup was given “18V XR” branding.
I should add that Dewalt eventually brought the XR – extreme runtime – branding to the USA to describe their premium 20V Max brushless cordless power tools and higher capacity batteries.
The popular opinion is that “20V Max” sounds better than 18V, where consumers might perceive 20V Max as delivering higher voltage or more power than 18V. It is also widely believed that “Max” branding is not widely used outside of North America due to other regions’ advertising and consumer protection regulations.
In recent years, some brands have eliminated the “Max” part of their cordless system branding. For instance, Bosch has renamed their compact cordless power tools as simply “12V” in Europe. Bosch still uses 12V Max in the USA.
Whether Dewalt “20V Max” was created for market distinction, user perception, or other reasons, it was in line with emerging standards.
Today, there are 12V Max, 20V Max, 24V Max, 40V Max, 60V Max, 80V Max, 120V Max, and other such cordless power tool systems.
18V still remains popular, although mainly with legacy systems. New cordless systems tend to be given “Max” voltage branding.
For example, Makita uses 18V to describe their core cordless system, and went with 40V Max to describe their new XGT cordless system.
Some brands, such as Dewalt, tend to be explicit and clear, requiring nominal voltage disclosures in all marketing materials. Others, such as Harbor Freight’s Hercules and Bauer brands, simply describe their cordless systems as 12V or 20V.
Most users should be accustomed to this by now.
I have found there to be far less confusion between 12V Max and 10.8V, or 20V Max and 18V than in earlier years.
However, occasional comments and questions, such as a recent reader statement that said “US batteries give you 2 more volts” make it clear that there is still some confusion or misunderstanding.
I have posted about Dewalt 20V Max vs. 18V twice before:
2011: Dewalt 20V Max = Dewalt 18V XR Internationally
2016: Dewalt 20V Max = 18V Nominally
This seems like one of those questions that needs to be revisited every couple of years.
Nathan
Nice – thank you for the time to put some history to it. Time does fly.
Stuart
Thanks! (In case you missed it, I also just added a historical timeline to the post.)
A lot of consumers try to vilify Dewalt for the “20V Max” terminology, but from what I could tell, they simply extended a trend that had already emerged and was quickly adopted by their competitors.
MM
I’m sure there is something of a marketing angle to it, as 20V max sounds more impressive than 18v, but speaking from personal experience I very much appreciate the name being clearly distinct from the old 18V Ni-Cd system:
When I started working I had only corded tools. I became familiar with many of the Ni-Cd lines which belonged to co-workers or the companies I worked for. I liked the 18V Milwaukee and Dewalt a lot but I couldn’t afford those and ended up with 14.4V Dewalt for my personal use. It wasn’t great but it was adequate for my purposes. Fast forward several years to around 2012 or so and I now found myself needing new cordless tools for my own business. I knew I wanted to buy something other than 14.4V NiCd–they performed OK, but it was clear that line played second fiddle to the main 18V line and I didn’t want to make that mistake again. So what to buy? I needed tools fast but I didn’t really have the time to do a ton of research. My previous job had a lot of 18V NiCd Dewalt and those performed great, maybe I should go with those, I thought? But when I started looking for new tools to buy the name “20V max” stood out for being so clearly different from “18v”; it was obvious that it was an entirely new better platform. And that was attractive to me, if I was going to buy multiple new tools I’d rather invest in a new system which had potential for the future, not an old-and-dying system that is on its way out. If instead I had seen “18v” and “18v XR” listed for sale I might not have caught onto the difference without having spent a lot more time researching, and that was time I didn’t have.
Melbourne Presswood
Has it occurred to you a purely resistive circuit will generate 23% more power at 20 vdc than at 18vdc. It’s not just marketing, it’s performance! The relationship is exponential relative to different voltages.
Stuart
In electrical power comparisons, you’re assuming that current draw remains the same, which might not be the case. Where are you getting 23% from? 20V is 1.11% greater than 18V .
In any case, it’s moot because 20V Max batteries and tools do NOT operate at 20V, they operate at a nominal voltage of 18V.
Take a Dewalt 20V Max tool and battery from the USA and a matching Dewalt 18V tool and battery pairing from the UK, Europe, Australia or similar. The performance should be identical. With no change in performance, the differences are in the branding/marketing.
Nate
Nicely done. Sorry to say that I perpetuated the European regulation thing in a comment response. Your Bosch 12V reference here was very educational. I do appreciate that DeWalt distinguished their 18v NiCad from the Li-Ion stuff with branding.
Stuart
There could very well be or have been regulations.
RussBroom
Yes, I have a strong feeling that this kind of marketing malarky would be illegal under EU regulation.
You only have to look at the confusion it’s created to understand why!
Kevin McCormick
Very helpful.
Doresoom
I still get comments on YouTube and from friends in person expressing how they prefer 20V tools over 18V tools for the extra power. Whether or not DeWalt meant to confuse customers intentionally with their marketing, it definitely has that effect.
One thing I very much disagree with in DeWalt’s branding is that they use max voltage to calculate watt hours. For example their 12V max 3Ah batteries say 36Wh instead of the true 32.4Wh. Milwaukee, Bosch, and Makita all use 10.8V for their watt hour calculations, even though they use 12V as the platform label.
Stuart
The Watt hours rating using 20V in lieu of 18V confuses me too, but is at least consistent. This tends to be a technical inclusion; I have never seen a cordless power tool brand advertise batteries with respect to watt-hour ratings.
Big Richard
That is not entirely true anymore. I don’t know when exactly they switched, but I have M12 batteries that use the 12v max voltage to calculate Wh. And they are genuine, they are not knock offs. Look at some newer M12 batteries if you have any.
MM
I just looked at some of my M12 batteries, purchased at HD in early 2021, and they use the 12v figure. For example the XC4.0 ah batteries say 48wh on the bottom, the 2.0’s say 24wh.
Doresoom
Interesting, I’ll have to take a look at some of my newer M12 batteries. The older ones were definitely using 10.8V for watt hour calculations. I’m a little disappointed in Milwaukee for switching. Seems like a case of “those other guys are doing it, so now we will too.” Like the ridiculous “reach” vs “standout” specs that happened with tape measures in the last few years.
MM
I just realized that I do have one quite old M12 battery, it is a 1.5ah that came bundled with an inspection camera. I never use it since I have so many other M12 batteries and I don’t want to bother with its low capacity when a 2.0 or 3.0 compact is the same size. I don’t recall exactly how old this tool but I’ve had it for at least 8 years. I dug out the battery, and curiously, it does not say the amp rating anywhere on it. It is, however, marked 12V, the part number (48-11-2401), and 16 wh. So in that case they took the 10.8 volt figure and actually rounded the result (16.2) down.
Big Richard
You are right Nate, the older M12s definitely used 10.8v. It’s odd because I can’t imagine they would have switched to match “the other guys”. As Stuart mentioned, brands don’t advertise by Wh, so why switch? We may never know.
Btw, if we wanna confuse things even more, DeWalt uses the nominal 18v to calculate Wh on their PowerStack batteries. 😮
Stuart
It’s possible that shipping, TSA, or other agency guidelines factor into watt-hour ratings.
I would suspect that, for such purposes, it’s best for Watt-hours to directly match stated voltage and amp-hour specs.
Let’s say one has 3x M12 or 12V Max batteries, each at 3Ah.
That would be 10.8V x 3Ah x 3 = 97.2 Watt-hours, or 12V x 3Ah x 3 = 108 Watt-hours.
If there’s a restriction set at 100 Watt-hours, enforcement might look at the voltage and charge capacity claims rather than the watt-hour rating, leading to discrepancies or unexpected actions.
Big Richard
Touche, the FAA regulations for lithium batteries on planes was one thought I had behind the change.
neandrewthal
100%. The Wh ratings are patently false. While you can certainly measure 20V or more, there is no scenario where you can get the rated Wh from these batteries., except maybe if you ignited them.
Morgan
Craftsman C3 19.2 baby!
Stuart
You previously said you retired all of your C3 cordless power tools years ago!
Morgan
haha! oh for sure I have. Way too deep down the red hole of Milwaukee now – even into MX.
I’m just pokin’ fun of the 19.2v advertising scheme
Stuart
In NiCad batteries, 15 cells x 1.2V = 18V. To my knowledge, 19.2V was simply 16 cells x 1.2V. I’m not sure what they when C3 started transitioning to Li-ion.
Jared
One other thing I think is worth mentioning in the context of the 20v/18v marketing is Dewalt’s decision to continue selling 18v Ni-cd tools and batteries alongside the new 20v line for quite awhile, followed by offering a 20v Max to 18v adapter. That is different from how some manufactures discontinued their Ni-cd tools when they released their lithium 18v lineup.
If you simply stop selling 18v Ni-cd tools and batteries, you don’t need to worry that your customers will be confused by how two 18v tools from the same manufacturer can be incompatible. On the other hand, if you make an effort to be backwards compatible and have two separate 18v-class tools being sold at the same time… might be nice to use the 18v/20v Max nomenclature to communicate the difference.
Eric
From what I understand, Dewalt’s lithium ion battery management is in the tool, but there’s an official adapter for lithium ion battery use on the old 18v NiCd tools. Does that adapter then need some sort of protection circuitry instead of being a simple physical adapter?
MM
I don’t know if that adapter has any circuitry inside it or not, however the adapter is designed to mechanically exclude certain batteries. We were just discussing this in a separate topic. The 5ah Power Stack battery and at least some of the Flexvolt batteries will not fit that adapter without modification. So my guess is that there is no protection circuitry in the adapter and instead they’re achieving that same goal by preventing you from using any battery powerful enough to overload the adapter.
Matt
I’m still rocking 18v Dewalt tools from the mid 2000s utilizing the adapter for 20v batteries. Who’s with me?
Mopar4wd
I do too plus I still have some 18v batteries working. My employer, still has dozens of 18V drills and batteries. They have started converting to 20V max but right now its still 50/50.
Hélder Mota
Eu compreendo que ainda aja confusão entre 20 V Max e 18v porque eu vivo nos Açores e temos é o sistema 18v XR o único que mudou foi de 10.8 V para 12v. O primeiro berbequim c/percussão que comprei foi o DCD777 de 14.4 V brushless da dewalt mas acho que as ferramentas de 14.4 V foram descontinuadas não sei o porquê. Comprei em 2013 julgando que ia exister continuação desta linha 14.4v o que tem de bom é que ainda funciona tudo muito bem
Translation via Google:
I understand that there is still confusion between 20V Max and 18v because I live in the Azores and we have the 18v XR system, the only one that changed was from 10.8V to 12v. The first hammer drill I bought was the 14.4V brushless DCD777 from dewalt but I think the 14.4V tools have been discontinued I don’t know why. I bought it in 2013 thinking that there was going to be a continuation of this 14.4v line, the good thing is that it still works very well.
Mike
Yeah, I think the 20V smoke and mirrors was another ‘differentiator’ to soften the blow to XRP (stem) users…..
Howard Twissell
Hi guys I am old and ancient but still like to pick up the tools. What is confusing me Is can and will an 18v xr de Walt run the 20v router. Sorry for being dumb , to much tech to keep up with
Stuart
Yes, it should. A Dewalt 18V XR li-ion battery from Europe will run a Dewalt 20V Max cordless router from the USA. The vise versa is true.
Howard twisell
Thankyou sir
Terry Estep
Can one charge the 20volt dewalt battery on the dewalt 18 volt charger?
Stuart
If it’s designed to charge 18V XR batteries such as the slide-connect-style battery shown in the post, then yes.
MAc
Can use 20V battery with 18V gear?
Stuart
Modern Dewalt 18V XR tools with slide-style batteries (typically) work with Dewalt 20V Max battery packs.