Cordless impact drivers, just like the case with most battery operated power tools, are dependent on the voltage of their batteries. The higher the voltage of the battery that an impact driver has, the more powerful it will be.
It’s simple enough to just go for the tool with the higher voltage, but before you do that, you need to consider if you have the right size of tool for the job.
An impact driver with just the right size and weight can make you more productive in the workshop or the job site, and these considerations are just as important as the power that your tool can produce.
Impact Drivers, Batteries and Voltages
Before we go into the pros and cons of each voltage, let’s take a look at how the manufacturers label and market their impact drivers. Some major manufacturers offer 12-volt impact drivers, while others have a more extensive line of 18-volt tools. A handful of tool makers, including DeWalt and Porter-Cable, also make and market their line of 20 volt Max impact drivers as well.
You might be surprised to find out that there is not much of a difference between a 10.8-volt impact driver and one rated for 12 volts. The same goes for a tool that says 18 volts on the label, and one marketed as a 20-volt impact driver. The reason for that is because of how the battery packs that go with your impact driver are built.
Most battery packs that come with power tools are actually made of a set of smaller battery cells arranged in series. This arrangement adds up the voltage in those smaller batteries – so the more batteries you have in a battery pack, the higher the voltage, and the more powerful the tools you can power with it.
A battery cell has a baseline voltage of 3.6 volts, so this is the nominal voltage rating for a cell of this type. These cells also have a maximum voltage of a bit over 4 volts too, a fact that many manufacturers take advantage of when marketing their power tools.
12-volt impact drivers use battery packs that come with 3 cells, with a combined max voltage of around 12 volts. 3-cell battery packs like these also have a combined nominal voltage of 10.8 volts. That is how you get 10.8-volt impact drivers and 12-volt impact drivers – they both run on similar battery packs, and they give you similar performance.
The same goes for 18-volt impact drivers that use battery packs with five cells. The combined nominal voltage neatly adds up 18 volts in this case, with five 3.6-volt cells arranged in series.
The combined max voltage on the same five cells also add up to 20 volts, and that’s how you get battery packs and power tools rated for “20V Max”. Just like the case with 12 volt and 10.8-volt impact, both kinds of tools can give you similar performance.
12 Volt Impact Driver Uses
When you need a compact, lightweight and easy to use impact driver around the home, a 12-volt tool could be the best fit for your needs. A 12 volt (or 10.8 volt, depending on how the manufacturer labels their tools) is a good starter tool for occasional use.
They pack enough power to drive screws and bolts for most installation tasks. They are also handy to have for professionals that need to use an impact driver in a variety of awkward spaces.
For HVAC installers, or steel framers that do a lot of overhead work on top of ladders or up in the rafters of a roof, a smaller 12-volt impact driver lets them work longer with less strain. These are lighter and more compact and tend to charge a fully drained battery very quickly.
18 Volt and 20 Volt Impact Driver Uses
For jobs that need a bit more muscle, a larger 18 volt (or 20 volt) impact driver can be a more efficient choice. Not only do the larger cordless impact drivers provide you a bit more torque for driving fasteners or turning bolts, but they also give you more battery power to work with.
Their larger batteries let you work a bit longer on tasks (generally speaking) for those jobs that are more demanding. For building decks, installing fences, and other large projects, having that extra torque, voltage and battery capacity can make a lot of difference.
18 volt and 20-volt impact drivers also let you get more use out of your tool in the garage, where the rated torques needed can exceed the output of a compact impact driver.
For loosening stuck bolts and screws, the higher torque of an 18-volt impact driver can make the difference between being able to loosen that stuck bolt and having to do it by hand. The higher torque outputs of the higher voltage impact drivers also make them a more practical choice if you use a socket adapter, as well.
12 Volt Impact Driver Size and Weight
The smaller battery packs and compact profiles of 12-volt impact drivers make them some of the most compact and portable tools you can add to your toolkit. A typical 12-volt impact driver, without the battery pack, weighs less than two and a half pounds.
Put the battery in, and you still have a tool that weighs less than five pounds – perfect for carrying around on your belt, even when climbing ladders or scaffolding.
Without a hex shaft adapter, a 12-volt impact driver is also a very handy tool at just seven inches or so. Some compact models come in even smaller packages than that, with some under half a foot long. This makes them easier to use in tight spaces, or around awkward spots and corners.
18 Volt and 20 Volt Impact Driver Size and Weight
Both 18 volt and 20-volt impact drivers use 5-cell battery packs, and it’s a given that they are heavier than 12-volt tools. A typical 18-volt impact driver weighs six pounds or so, easily more than a compact impact driver.
Of course, most of these tools also come with larger motors and more features to take advantage of all that extra power. That translates to extra length and size to accommodate all the extra gearing. You will find 18-volt impact drivers measuring around a foot long, and even longer than that with an adapter or hex bit attacked.
12 Volt Impact Driver Torque
Compact 12-volt impact drivers can give you anywhere from 1,200 to 1,600 inch pounds of torque, which is plenty for a lot of driving and turning tasks around the house.
With that kind of turning power, you can already drive long screws into hardwood with a tool weighing less than six pounds. The amount of torque you can get out of a model depends on a few factors, too.
Cordless impact drivers with brushless motors can put out more power at a better efficiency compared to conventional motors – the trade-off is that they are significantly more expensive to own.
18 Volt and 20 Volt Impact Driver Torque
The larger 18 volt and 20-volt impact drivers deliver more torque than the smaller 12-volt models, as can be expected. An entry level 18 volt model will give you more than 1,300 inch pounds of torque, which is not that much more than a compact impact driver. A good 18-volt model, however, can easily put out 2,000 inch pounds and more, which is plenty of turning power for any but the toughest of tasks around the home.
At this torque range, it becomes practical to use socket adapters and use your cordless impact driver for some tasks that may call for an impact wrench. Having this much torque on your impact driver expands the range of tasks you can do with your tool, which makes it a more worthwhile investment.
12 Volt Impact Driver Cost
12 volt impact drivers are affordable tools overall, and they make for a good entry level investment if it is your first time adding an impact driver to your toolbox.
You can get one for as low as under 45 dollars, and you already get a capable tool that can put out 1,000 inch pounds of torque – more than plenty for driving screws and fasteners around the house. Another good thing when it comes to 12-volt impact drivers is that you can get a whole kit, including batteries, charger, and case, for under 100 dollars.
18 Volt and 20 Volt Impact Driver Cost
18 volt and 20-volt impact drivers pack plenty of power, but also represent a significant investment on your part. You can get an 18-volt impact driver for as low as under 60 dollars, and some of the better ones will set you back around 75 dollars or so.
Once you get into the kits, it gets even more expensive – expect a basic set with battery and charger from a good brand to go for no less than 150 dollars new. If you do need the running time and power that an 18 or 20-volt impact driver set can give you, then it’s all money well spent.
