20V Max or 18V battery, which one is more powerful?
“When I switch from an 18V system to a 20V system, there is a significant difference in power.” Ah, if only I had a quarter every time I heard that… No matter how many times I jump into someone’s conversation and explain it to them, the 18V vs. 20V Max debate continues. But let me clear the air and assure you, they’re essentially the same. Yes, I mean it.
I wish I could end it there, but people persist in claiming that a 20V Max system is more powerful than an 18V because 20 is greater than 18. Sigh.
Internal 18V and 20V: The Story Behind the Scenes
Seriously, though, I love discussing this topic, so let’s dive in. In the US, leading manufacturers such as Bosch, Milwaukee, Ridgid, Ryobi, and Makita all operate on 18V battery platforms. On the other hand, DeWalt and Porter-Cable use their 20V Max systems. You may wonder how we can prove that they’re the same. Well, all it takes is a voltmeter to gather some quantifiable data and a quick look inside the battery to uncover the truth.
20V Max has the Same Battery as 18V Battery
Inside the battery pack, you’ll find individual battery cells. In both 18V and 20V Max systems, these cells are always arranged in series of 5. Then, each group of 5 cells is connected in parallel to increase the battery’s amp-hours and overall capacity, measured in watt-hours. If you want a more detailed explanation, be sure to check out our feature on Voltage vs. Amp Hours.
Each battery has two voltage ratings: a nominal voltage and a maximum voltage. When a battery is fully charged, it produces a higher voltage than when it begins to discharge, even if the difference is minimal. This is actually a chemical property of the lithium-ion system. Each cell in these batteries has a nominal voltage of 3.6 volts and a maximum voltage just over 4 volts.
- 3.6 volts (nominal) x 5 cells = 18 volts
- 4 volts (maximum) x 5 batteries = 20 volts
And that’s it. That’s the only difference between 18V and 20V Max batteries. It’s merely a matter of whether the company uses the nominal voltage or the maximum voltage as the rating.
20V vs. 18V: The Battle of Marketing
This brings us to some interesting points. First, many European countries have stricter regulations on how companies advertise their products. In most areas, tools are sold based on their nominal voltage. Hence, you’ll find 18V high power tools and 10.8V tools in those markets. From a marketing perspective, higher numbers on a tool make it appear more powerful. However, applying the nominal voltage label indicates the range where the battery is primarily designed to operate.
For some reason, the 20V Max vs. 18V debate seems to be specific to the 5 battery pack platforms. Everyone focuses on advertising their 12V series (3 cells) rather than their 10.8V series. Moving to OPE (Outdoor Power Equipment), we encounter 40V systems (10 cells) that have replaced the 36V platforms from a few years ago. So, before you develop a negative impression of DeWalt or Craftsman power tools, know that this marketing strategy is prevalent across the industry.
20V MAX is the Same as 18V Nominal – Proven by DeWalt
The crux of the entire debate might lie in visiting the DeWalt 20V MAX website and noticing the asterisk. On the DeWalt 20V Max page, you’ll find an asterisk next to each mention of 20V MAX. Further down the page, you’ll see the following clarification:
“20V MAX* – 20V initial maximum measured at no load, 18V nominal”
When you examine DeWalt and Craftsman tools, you’ll notice the 20V MAX* labeling on their packaging. The asterisk and the word “MAX” refer to a document that explicitly states the voltage rating is the maximum value. Is this a marketing tactic? Yes. Is it misleading? Not if you seek explanations when you see something marked with an asterisk.
- Barry Bonds, single-season home run king* – known to have used performance-enhancing drugs
- Double Chocolate Fudge Brownies, bake 25 minutes* – 18 minutes at high altitude
- 20V MAX* – 20V initial maximum measured at no load, 18V nominal
Conclusion: Setting the Record Straight
So, to reiterate, 18V and 20V MAX systems operate on the same voltage. Let me say it once again: an 18V battery and a 20V MAX battery deliver the exact same voltage. However, it’s worth noting that the internal details of each cell may vary from brand to brand, and even within the same brand. Technology and chemistry are ever-advancing. Therefore, DeWalt’s 20V MAX tools are indeed more powerful than their original 18V counterparts, thanks to improved electronics, motors, and batteries. Nevertheless, both systems provide the same voltage for your tools.
If my word isn’t enough, take DeWalt’s word for it!