18V Vs 20V MAX Battery Drills: Performance Comparison

When deciding between an 18v and a 20v drill, particularly in popular brands like DeWALT, it’s important to understand their power and performance nuances.

In practical terms, the choice between 18V and 20V models involves more than just comparing voltage numbers. It’s crucial to consider how these drills perform in real-world applications.

Battery Voltage Comparison – 18v vs. 20v Drills

Battery Type	Nominal Voltage	Maximum Voltage
18v Battery	18 volts	Up to 20 volts
20v Battery	18 volts	Up to 20 volts

• Nominal Voltage refers to the standard operating voltage under typical usage conditions.
• Maximum Voltage is the highest voltage the battery can reach, usually at full charge before use.

This chart illustrates that while both 18v and 20v batteries have the same nominal voltage, they are marketed based on their maximum voltage capacity. It highlights the fact that the practical difference in voltage between these two types of batteries is minimal, despite the different labels.

Lithium-Ion Batteries On Paper

It used to be nickel-cadmium batteries were the thing, but that all changed with the fairly recent lithium-ion battery technology development.  We now use them on our cordless tools:  they are easy to recharge and contain battery cells of 1.2 volts, 1.5 volts, and 3.6 volts.  

Groups of 5 cells are connected and wired in a series, and in the case of cordless tool battery packs, every group of 5 cells is connected through a wire in parallel.  This ensures the battery will have a high number of amp hours and a good volume of watt-hours.

Some simple math tells us that 5 cells, each of which is 3.6 volts, add up to 18 volts.  The cordless drill I used yesterday is an 18v tool, certainly powerful enough for all of my household and woodworking shop uses, and it is powered by a battery pack that has 5 cells of 3.6 cells wired together to give me the voltage the cordless drill needs.

All cordless power tool manufacturers source the cells from third parties and assemble them in battery packs.  The battery slots on the power tools and the branded battery charger are made such that they fit the branded battery pack well and tightly, resulting in a power tool that is effectively and efficiently powered for use.

In addition, branded battery packs are manufactured to communicate well and smoothly with the motors in the branded power tools.  This enhances the efficiency of tool operation.

Lithium-Ion Battery Cells

As we calculated, a string of 5 cells, each of which is 3.6 volts, has a total of 18 volts and powers 18v tools.  But this is where the “on paper” and “on the field” comes in.  

Each individual battery cell has a maximum voltage, its full potential, of 4 volts.  That’s the “on paper” number.  Again, simple math tells us that 5 cells in a group times 4 volts each is going to equal 20 volts.  This represents the potential or maximum voltage of the batteries.

However, batteries aren’t used “on paper”: we use them in the real world.  Each cell has a real-world or what is referred to as a nominal voltage rating of 3.6 volts, and the math has already told us that 3.6 times 5 is 18 volts. This nominal voltage is what we get from the battery when we pull the trigger and use our cordless tools. 

Then, we need to understand maximum and nominal voltage, one on paper and one on the cordless tools we use.  In fact, these are just words, words that are used in marketing and labeling “on paper.”

The only difference that matters, then, is the manner in which manufacturers label and promote their batteries and not the actual way in which the batteries perform.  However, promotions of 20V Max batteries are limited to the United States; outside of the US and Europe, companies are required to use the nominal voltage rating of batteries and not the maximum voltage rating.  

Sure, 20V sounds like more than 18V, and on paper, it is.  But, “the proof is in the pudding,” to use another old expression – the truth of something being judged on actual experience with it, on its results rather than its potential.

Yet, some will argue that 20V batteries are more powerful than 18V batteries, and they can “feel” it in the use of their cordless power tools.  They will have paid more for the battery and the cordless tool they use the battery with, under the belief it will give them more juice and more torque (the turning power) of the tool.

I know my 18V drill is equally powerful whether I’m using a 20V Max battery or an 18V battery.

Understanding DeWALT’s 20v Max Battery Technology

DeWALT’s approach to battery technology, particularly with its 20v Max line, showcases a blend of innovation and marketing strategy.

The 20v Max platform, including the FlexVolt system and Battery Stack batteries, represents DeWALT’s commitment to providing versatile and powerful solutions for cordless tools.

For instance, the Battery Stack 20V Max is designed for longer run times and cooler operation, offering a compact design with efficient power delivery.

DeWALT’s FlexVolt batteries are engineered to power both their 60v and 20v tools, demonstrating the brand’s focus on flexibility and performance. While the 20v Max battery is marketed with an initial voltage of 20 volts, it’s important to understand that this is a maximum value, with the actual working voltage aligning with the standard 18 volts in practical use.

While unique to DeWALT in the U.S., this marketing approach aligns with the industry’s trend of highlighting maximum potential to showcase power capabilities. However, the real-world performance of these batteries remains consistent with the nominal voltage standards, ensuring reliability and efficiency in various applications.

Don’t take our word for it, either.  Go here to see for yourself.  

Which Should You Buy – 20V Max or 18V Drills?

When selecting between 20V Max and 18V drills, several key factors should guide your decision:

1. Cost: Consider your budget and the value you get for the price. While DeWALT is known for its quality, remember that higher cost doesn’t always equate to better performance for your specific needs.
2. Torque: The drill’s torque, or turning power, is crucial. More torque translates to more efficient and effective performance, especially for demanding tasks.
3. Weight: Evaluate the weight of both the drill and its battery. A lighter tool reduces fatigue and enhances comfort during extended use, which is vital for both professionals and hobbyists.
4. Features: Additional features like settings, lights, indicators, and ergonomic design can significantly improve the user experience. Sometimes, a well-equipped 18V drill might serve your needs better than a basic 20V model.

Task Type	18V Drill Suitability	20V Drill Suitability
Light DIY Projects	Highly Suitable	Suitable
Home Repairs	Very Suitable	Suitable
Heavy-Duty Professional	Suitable	Highly Suitable
Precision Woodworking	Very Suitable	Suitable
Construction Work	Suitable	Highly Suitable
Furniture Making	Very Suitable	Suitable

Ultimately, the choice between a 20v Max and an 18v drill should be based on how well the tool fits your specific project requirements and personal preferences rather than solely on battery voltage.

Advancements in Battery Technology: Impact on 18v vs. 20v Drills

The progression in battery technology, particularly the shift from nickel-cadmium to lithium-ion batteries, has been a game-changer in the power tool industry. This advancement is central to the discussion of 18v versus 20v drills. Modern lithium-ion batteries offer improved efficiency, longer life, and more consistent power output, directly enhancing cordless drills’ performance.

In the context of the 18v vs. 20v debate, it’s important to understand that while marketing often highlights the maximum voltage (20v) for impact, the real-world performance of these batteries aligns more closely with their nominal voltage (18v). This means that the perceived power difference between 18v and 20v drills may not be as significant as it appears on paper.

The advancements in battery cell technology and electronic control systems within these drills have led to more efficient power usage and better overall tool performance. This means that whether you choose an 18v or a 20v drill, you are likely to experience similar levels of efficiency and effectiveness in most typical applications.