One of our mantras at Obsessed Woodworking is “the right tool for the right job.” We’ve woven other words into that mantra, and today we weave another into it: the right battery for the right tool.” We don’t force tools designed for one task to perform another task for us; we follow the rule and stay true to the mantra.
It isn’t true that a battery is a battery. You don’t try to fit a D battery in a penlight that uses AAA batteries. It simply won’t fit. The penlight is designed to run on AAA batteries and doesn’t need the power of a D battery, and besides, it’s just too big. In the same respect, you don’t try to run a high-beam flashlight built for D batteries with a few AAA batteries, and again, they simply won’t fit.
In the woodworking shop, with our cordless power tools, we follow the same rule and make sure we choose the correct batteries for each of them. In today’s woodworking shop, we use lithium-ion batteries and choose the correct voltage battery pack to power any particular tool.
Lithium Ion Battery Packs
We know lithium-ion batteries, and we all have them in our shop. The technology is somewhat new to the woodworking industry and replaced nickel-cadmium batteries that were used to power our cordless tools.
They’re easy to charge and come with a 3 – 5 year lifetime. They are made up of cells that range from 1.2 volts up to 3.6 volts. They are grouped as 5 cells connected and wired in a series, and every group of 5 cells is wired in parallel to ensure an ample (pun intended) number of amp and watt-hours.
This is how the battery packs are able to keep a constant level of power for the tools until the charge has run its course and needs a recharge.
We also know that each power tool manufacturer makes their own battery packs and sources these cells from third parties. They design their battery packs to work only with their own family of cordless power tools, and in most instances, the battery packs are not compatible with any other brands’ power tools.
We say “in most instances” because there are workarounds, modifications, and adapters that can force a battery from one manufacturer to work with a power tool from another manufacturer. We don’t recommend this both for safety reasons (yours and your tool’s) and so as not to void the warranties that came with your tool and the battery.
Lithium Ion Battery Cells
As we noted, cells come in voltage ratings of 1.2v, 1.5v, and 3.6v. Mixing and matching these voltage ratings gives us the total voltage of the battery pack as it is assembled. Five cells each of 3.6v adds up to 18 volts, and it’s likely we all have an 18v battery pack to power our 18v cordless power tools.
In a recent post on these pages, we discussed DEWALT’s 20v MAX batteries and distinguished between the maximum possible voltage and nominal voltage. The maximum voltage, the power that generates the torque to turn our drills and saws, is in the abstract: turn the power tool on and just let it spin, and you are experiencing its maximum voltage, but start working with it, and the output drops to 18 volts, the nominal voltage.
In the case of 3.6v cells, their “on paper” maximum voltage is 4v, and 4 x 5 = 20 volts maximum. However, their nominal, or “real world,” voltage is 3.6v, and 3.6 x 5 = 18.
To give you an idea of the varying powers of batteries and your tools, here’s a quick guide:
- A voltage of 4 to 8 volts is sufficient power to operate a cordless screwdriver
- A voltage of between 12 – 18 volts will power your tools for around the house and common woodworking shop tasks
- A voltage of 20 volts and up is for heavy tasks, remembering that with higher voltage comes larger and heavier battery packs to run those larger and heavier cordless power tools
DEWALT Battery Packs
Now we turn to DEWALT and its various battery packs and voltage ratings. We’ve mentioned their 20vMAX batteries and made clear what that designation really means. Generally speaking, battery compatibility is based on the battery and the cordless power tool operating on the same voltage.
Remember, too, that battery packs are designed and built to fit the DEWALT brand line of power tools. The size, weight, and connection slots on both the power tool and the battery pack are built to fit. The battery communicates with the brushless tool motor to maximize efficiency and effectiveness in its operation.
The exception to these general statements is the DEWALT Flexvolt battery. It has the advantage of automatically adjusting voltage when more is needed for the task you are working on at the moment. Thus, it’s “flexible” in its voltage output – the power that generates the torque our power tools need to turn (drills, saws).
The Flexvolt battery platform is a new technology used by DEWALT for its power tool line, designed and built to be compatible with 20v and 60v models. This changes things slightly as to what battery you should have handy for your DEWALT tools and affects the answer to the question for this article slightly.
Is A 20v Battery In A 60v Power Tool Like A Square Peg In A Round Hole?
Sort of, but not always. Let us explain.
A 20v MAX battery pack would be that square peg if you tried to use it to power a 60v tool. It doesn’t generate enough power to run that tool. When you are wanting to use a large power tool like a joist drill, for instance, you need a battery with enough voltage to turn that drill. Joist drills require a lot more torque than an 18v drill that is creating a pilot hole or a pocket hole. For that task, you’d need a 60v battery pack.
We also want to mention that a 20vMAX battery would not fit a 60v power tool. That is on purpose. It just doesn’t generate enough juice to run the larger power tool. It’s too weak, and the compact battery size will neither fit nor work.
This is where the DEWALT FLEXVOLT battery comes in handy. A FLEXVOLT 20v/60v battery pack will work with both 20v and 60v tools in the DEWALT line of tools, whereas a 20vMAX battery will simply not fit. The FLEXVOLT battery will “flex” to answer the call for more power when used with a 60v tool like a joist drill and reduce power when used with a 20v tool.
We should also mention that a FLEXVOLT 20v/60v battery pack can be charged by both 60v and 20v chargers. Finally, we should also mention that FLEXVOLT batteries are larger and heavier than a straight 20v battery; they will work with any tool that uses a 20v battery and just “flex” the power down, but 20v batteries will neither fit nor work with 60v tools.
With that advantage comes a higher price point, though, as you might expect. It is convenient, though, and convenience can be valuable depending on the work you do. If your projects are small, common to a home woodworking shop as a hobbyist or enthusiast, you might not need to pay up for that convenience.
It is likely, though, that those in the construction business might find it a necessary convenience both for the tasks they need their power tools for and also to keep the work going as they switch from tool to tool on the job site.
Video Display of 20v and FLEXVOLT 20v/60v Batteries
Here’s a very quick video that shows these two battery packs and what voltage tools they will work with. You will see the difference in size and weight and see how they both fit 20v tools.
The answer to the question, then, is both yes and no, and we’ve just explained why both answers are correct.