DeWalt 20V Max FlexVolt Advantage Hammer Drill Review DCD999

dewalt flexvolt advantage hammer drill
PTR Review
  • Pro Rating 9.4

The DeWalt FlexVolt Advantage hammer drill is competitive with a 5.0Ah battery and crushes the competition with a FlexVolt pack. It's an interesting dynamic between weight and performance, but I think it works in DeWalt's favor. Stick with the 5.0Ah pack for most of your drilling and driving, then pop that FlexVolt battery in for your high demand drilling.

Overall Score 9.4 (out of 10)

DeWalt FlexVolt Advantage Hammer Drill Pulls More Power and Crushes the PTR Test Track

The DeWalt 20V Max Hammer Drill with FlexVolt Advantage doesn’t look much different from the DCD997 hammer drill we’ve been using for the past couple of years, but what you can’t see promises to make a world of difference.


  • Super quick on the PTR Test Track
  • Impressively faster work with high demand accessories using a DeWalt FlexVolt battery
  • 3 speeds
  • Tool Connect chip ready
  • LED light controls on the foot


  • You have to use a heavy battery to get the best performance

Be sure to also check out our article on the Best DeWalt Drill

DeWalt FlexVolt Advantage Hammer Drill Design

We’re going to run this drill through the PTR Test Track—3 times, in fact. But first, let’s take a quick tour of the drill’s features.

There’s a general design that doesn’t stray far from DeWalt’s top-end offerings. You see it in the standard hammer drill, its Tool Connect version, a Power Detect model, and now, a FlexVolt Advantage option.

You switch between the three gear modes on top of the drill and LED light controls now appear on the foot.

Bare, the DeWalt FlexVolt Advantage hammer drill weighs 3.6 pounds—just a couple of ounces more than the Tool Connect model we’ve been using. The battery you choose takes over from there.

  • Bare Tool: 3.6 pounds
  • 2.0Ah Battery and Tool: 4.4 pounds
  • 5.0Ah Battery and Tool: 4.9 pounds
  • 6.0Ah FlexVolt Battery and Tool: 5.9 pounds

But it’s what’s inside the housing that makes this drill so compelling. FlexVolt Advantage technology is an electronic system that senses the battery you’re using. When you slide a FlexVolt battery in, the electronics tell the motor to boost the performance in a major way.

dewalt flexvolt advantage hammer drill

How much more? DeWalt tells us to expect better than 40% more power when using a FlexVolt battery.

DeWalt FlexVolt Hammer Drill Test Track Performance

We started with a 2.0Ah battery, switched over to a 5.0Ah pack, and finally, ran the track with a 6.0Ah FlexVolt battery. If you’re not familiar with the PTR Test Track, here’s what it entails on a 2×4 stud:

PTR Test Track

  • Drywaller’s Gambit: 20 drywall screws
  • Low Voltage Pull: 10 x 1/2 twist bit holes
  • EMT Bend: 10 x 3/4-inch spade bit holes
  • Pex Pull-Through: 10 x 3/4-inch auger bit holes
  • Deadbolt & Lockset: 1-inch hole saw and 2 1/8-inch hole saw

Five bit changes and adjustments to what gear you’re in are a must, adding a practical component (and the possibility of human error) into the test.


Even with our initial tests out of the box, we didn’t think there was any doubt the DeWalt FlexVolt Advantage hammer drill is much faster with a FlexVolt battery. What we need to know is how much faster and where these runs showed up on our PTR Time Trials leaderboard.

Running the DCD999 with a 2.0Ah battery, the total time was 3:36. The time to beat is 2:34 (DeWalt’s DCD997), so it’s about a minute short and good enough for 6th place overall.

The 5.0Ah battery improved things significantly. It beat the 3:00 minute mark and came in at 2:57, just sneaking into 4th place over Makita’s XPH07.

Now for the FlexVolt battery. It crushed the PTR Test Track with a blistering 2:19, taking over first place by 15 seconds!

That’s impressive, but it’s not 40% faster. Actually, it’s 36% faster than with the 2.0Ah battery, so it is close.

How About a Little More Objectivity?

Here’s the thing—the test track is fun, but it’s not scientific since there’s so much room for human error. So let’s highlight the toughest part of the course—the two hole saws.

The 2.0Ah battery needed 11.37 seconds to finish the 1-inch hole. The FlexVolt battery gave the drill enough power to make it through in 4.35—a massive 62% faster.

And it gets even better with the larger hole saw. With the 2.0Ah pack, we needed 38.62 seconds to get through. But it was just 6.17 seconds with the FlexVolt battery. That’s 84% faster! 2-⅛” hole saw shots

1-Inch2 1/8-Inch
2.0Ah Battery11.37s38.62s
5.0Ah Battery8.33s21.38s
6.0Ah FlexVolt Battery4.35s6.17s
DeWalt FlexVolt Advantage Hammer Drill Hole Saw Results

We need to keep in mind that DeWalt’s claim is about increased power, not speed, so our percentages are relative. But I think we can all agree that the performance boost we gain is huge.

These tests also show us that the harder the task, the more you gain from the FlexVolt Advantage technology. That’s something to keep in mind as you’re deciding what drill to buy.

DeWalt FlexVolt Advantage Hammer Drill Price

Let’s talk about price. You can pick up the DCD999 as a bare tool for $179 or in a kit with a 6.0Ah FlexVolt battery for $279. There are several combo kits available as well.

We recommend taking a look at the DCK2100D1T1 kit for $399.

  • DCD999 FlexVolt Advantage Hammer Drill (with side handle)
  • DCF887 Impact Driver
  • 6.0Ah FlexVolt Battery
  • 2.0Ah Compact Battery
  • Charger
  • Kit Bag

The Bottom Line

The DeWalt FlexVolt Advantage hammer drill is competitive with a 5.0Ah battery and crushes the competition with a FlexVolt pack. It’s an interesting dynamic between weight and performance, but I think it works in DeWalt’s favor. Stick with the 5.0Ah pack for most of your drilling and driving, then pop that FlexVolt battery in for your high-demand drilling.


  • Model: DeWalt DCD999
  • Max Speed: 2000 RPM
  • Blow Rate: 38,250 BPM
  • Power: 1219 UWO
  • Length: 8.4 inches
  • Weight: 3.6 pounds bare
  • Warranty: 3 years

Learn more at DeWalt’s website.

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I just purchase the DCD999 to use most exclusively with my K Drill ice auger. I can’t use speeds 2 or 3 as it shuts the drill off. I didn’t know this until I did extensive research on the web. I thought something was wrong with the drill. Maybe there is???


does the tool connect chip enable anti kickback as it does with the 997?


It is $399 for the kit, not $299


I have the DCD996, DCD998, and DCD999 and I personally think the DCD998(power detect) has more power than the DCD999(flexvolt advantage). But to be honest the DCD996 has more than enough power for everything I’ve ever done. However the newer drills do have a significantly more power.


So is it switching to 60V with the flexvolt battery?

Would love your thoughts, please comment.x