Last Updated on September 5, 2021 by Barry Gray
There are a few different kinds of DeWalt batteries, but the main categories are the three voltages: 12 volts, 20 volts, and 60 volts. They will last different lengths of time depending on what tools they’re used with and in what way.
Measuring battery duration is complicated, and it’s difficult to compare two very different batteries. First you need to understand how battery life is measured, and then you can dig into how long specific batteries last and what terms like “Flexvolt” mean. Then it’s helpful to have other tips like how to make batteries last longer.
How Do You Measure Battery Life?
Because battery duration depends on how quickly the energy is used, it’s measured in amp hours (Ah) which tells you how for how long the battery can deliver a certain amount of power. For example, a battery measured at 20 amp hours can provide 5 amps for 4 hours before you need to recharge it.
You might also see watt hours (Wh) as a measure of battery life. A watt hour is equal to the number of amp hours multiplied by the voltage of the battery. For example, a 20V battery with 100Wh has 5Ah.
That might seem confusing at first, but consider how you use batteries. A 20V battery will drain faster than a 12V battery because it’s using its energy more quickly, so just looking at amp hours isn’t always enough information.
What Does Flexvolt Mean?
DeWalt’s Flexvolt batteries are a newer, special lineup they’ve begun offering lately. The name is related to their primary feature: that they can change their voltage between two settings.
Changing voltage has two advantages: first, there are certain tools that are made to only work with a specific voltage. Having a Flexvolt battery means that it can power a wider variety of tools. But changing voltage can also help you make your battery last longer because a lower voltage will drain the battery more slowly.
Flexvolt batteries can come at a premium though. You should pay attention to the individual battery’s price, and compare that to the price of two batteries of different voltages.
DeWalt Battery Durations Compared
The durations of different DeWalt batteries are affected by factors like the battery’s size and voltage, as well as when the battery was released. Flexvolt batteries’ durations can also vary significantly depending on what voltage you use them on.
DeWalt 12V Max Batteries
The smallest main line of batteries that DeWalt sells right now is its 12V Max batteries. These are designed to power its 12V Max line of tools. They aren’t compatible with any of DeWalt’s other tools, so make sure you’re looking at the right battery before making a purchase!
The 12V Max batteries have a capacity of 3.0 Ah. That means that if you’re pulling one amp of electricity per hour, it will last for three hours, but if you’re using three amps per hour it’ll only last for one.
As you might’ve guessed, 3.0 Ah isn’t the largest capacity in the DeWalt lineup. That’s because this is a lighter, more portable battery meant for DeWalt’s most compact tools. The smaller battery might not last as long, but it’s easy to move and maneuver with.
DeWalt 20V Max Batteries
DeWalt offers more variety with its 20V Max lineup of batteries. While many of these batteries have the same 3.0 Ah capacity as its 12V Max batteries, there are also even more compact options in this lineup. 20V Max batteries come in 1.5 Ah, 2.0, 3.0 Ah, 4.0 Ah, 5.0 Ah, and 6.0 Ah varieties.
Obviously, these different battery capacities will have widely varying expected durations. Although they’re all compatible with the same tools, the batteries will have different applications depending on the kind of work you plan on doing.
On average, the batteries with lower amp hours will be smaller and lighter than the ones that have greater capacity, which is the tradeoff for the difference in duration. The 20V Max batteries can have other features like oil resistance and lanyards as well.
DeWalt 20V Max XR Batteries
DeWalt’s 20V Max XR lineup may seem similar to the 20V Max batteries, but it actually offers a significant difference in performance. The 20V Max XR lineup is not compatible with the same tools as the 20V Max batteries, and the tools in the lineup are typically more compact and have brushless motors.
20V Max XR battery capacities come in a wide variety of sizes, including 5.0 Ah, 6.0 Ah, 8.0 Ah, 10.0 Ah. Just as with the 20V Max batteries, the 10.0 Ah batteries in this lineup will be heavier than the 5.0 Ah batteries. But you’ll also notice that the smallest Max XR batteries are about as large as the biggest batteries from the other set.
That difference in amp hours is due to the Max XR batteries’ ability to store more power with less weight. That means that an 8.0 Ah battery can still be less than a pound, which puts it in the same weight class as some batteries that store much less power.
DeWalt 20V/60V Flexvolt Batteries
It’s a little trickier to talk about how long Flexvolt batteries will last. That’s because their durations will change dramatically depending on whether you use them with 20V or 60V tools. For that reason, we can look at how long they’ll last on purely the 20V and purely the 60V settings, and you can use that to estimate how long they’d last for you.
When they’re on their 20V settings, many of DeWalt’s Flexvolt batteries offer impressive durations. Their least expensive and most lightweight option can deliver up to 6.0 Ah, and there are other models that offer 9.0 Ah, 12.0 Ah, and even 15.0 Ah. Clearly, at the 20V setting this is an impressive and long-lasting lineup.
Of course, those numbers shrink down quite a bit when you set them to 60V. In fact, you can calculate it by yourself by dividing the original amp hours (or the number advertised on the package) by three. So the 6.0 Ah battery offers 2.0 Ah, and the others become 3.0 Ah, 4.0 Ah, and 5.0 Ah.
Those are still impressive amounts of power to provide to the large, energy-intensive motors that DeWalt’s 60V power tool lineup has. If you’re thinking about using those 60V tools, it looks like you’ll have to get the Flexvolt batteries anyways–they’re DeWalt’s only 60V batteries.
But they can also be good for people who only have 20V tools to give you the flexibility to upgrade in the future. They also have the most amp hours of any of DeWalt’s batteries, so if you need a long-lasting 20V battery, this might be your choice regardless of its Flexvolt features.
How To Make DeWalt Batteries Last Longer
If you’re using a power-intensive DeWalt power tool, you’ll want to make your batteries last as long as they can. But there are a few important steps to take when you’re handling your batteries to make sure you get as much power out of them as possible.
First, you should make sure to charge your batteries in a room temperature place in the shade. If you charge your DeWalt batteries in temperatures from 40°F-105°F, you’ll be able to charge them to their full capacity. But DeWalt batteries that are too hot or too cold, or that overheat from exposure to direct sunlight, don’t hold their full charge.
Next, you should also make sure that you give your batteries enough time to charge. Some DeWalt batteries take as long as eight hours to charge all the way, so you should check the energy gauge at the side of the battery to be certain that they’re fully charged.
You should also make sure to use the battery regularly. Batteries degrade when neglected for extended periods of time, so using them often will prevent that kind of decrease in condition. Even if you don’t really need to, try and get your battery down to 70% of its capacity on a regular basis.
Finally, don’t use the full battery before recharging it. That goes against the common wisdom for certain batteries, but DeWalt’s high-quality lithium-ion batteries actually fare better if you recharge them when the tool starts to slow down, rather than when the battery runs out completely.