DEWALT DCF845B Review: a compact 20V impact driver that hits hard for its size

I’ve been using the DEWALT 20V MAX XR Impact Driver (DCF845B) for a while now on random house projects, some deck work, and a couple of car jobs. I’m not a contractor, but I do enough DIY that a cheap drill/driver combo wasn’t cutting it anymore. I wanted something that could actually drive long screws into studs and structural lumber without smoking or stalling every five minutes.

I bought the bare tool version because I already had a couple of DEWALT 20V batteries from an older drill. That’s important: this thing comes as tool only. No battery, no charger, and not even a bit. If you’re new to the DEWALT ecosystem, keep that in mind, because a battery and charger can easily add a good chunk to the total price.

First impression out of the box: it feels compact and surprisingly light, but not like a toy. The 3-speed selector and the triple LED light on the front are the first things you notice. Compared to the basic impact drivers I’ve used before, this one looks more thought-out for actual daily use, not just the occasional Ikea build.

After a couple of weekends driving deck screws, lag screws, and some pretty stubborn Torx fasteners, I can say it’s not perfect, but it does the job very well for most tasks. It has plenty of torque, decent control, and the size makes it easy to use in tight spaces. If you already own DEWALT 20V batteries, it’s a pretty solid upgrade from the cheaper or older impact models.

In terms of price, the DCF845B sits in that mid-to-high range for impact drivers, especially if you look at what you actually get: just the bare tool. If you already own DEWALT 20V batteries and a charger, the value is pretty good. You’re basically paying for a compact, brushless, 3-speed impact driver that has more torque than the older models and the ATOMIC version, without paying for a full kit you don’t need.

If you’re starting from zero, though, the story changes. You’ll need to add at least one battery and a charger, and ideally a set of impact-rated bits. That can push the total cost quite a bit higher. At that point, some competing brands or bundled kits might look more attractive on paper. Ryobi, for example, often sells full kits with batteries and a bag for roughly the same price as this bare tool plus one DEWALT battery. But from my experience, the DCF845B has more punch and feels more compact and balanced than many budget options.

Where it earns its keep for me is the combination of size, power, and control. The three speed settings and the smooth trigger mean I can use it for delicate jobs and heavy jobs without swapping tools. I don’t need one driver for cabinets and another for framing. That saves time and hassle, which has value even if you’re just doing weekend projects.

Overall, I’d rate the value as good, not mind-blowing. It’s not the cheapest impact driver out there, but you’re paying for a tool that feels like it’ll last and that actually has the torque and features they advertise. If you’re already in the DEWALT 20V ecosystem, it’s an easy choice. If you’re not, you should compare full system costs (batteries, chargers, other tools) before jumping in.

The design is typical DEWALT: black and yellow, fairly chunky-looking, but once you pick it up, it’s actually quite compact. The tool itself is around 5.1" long and weighs about 2.2 pounds without a battery. With a 2Ah battery, it still feels light enough to use overhead without your arm dying after a dozen screws. Compared to the smaller ATOMIC version, this XR is only slightly larger but noticeably stronger, which is a good trade-off in my opinion.

The 3-speed slider at the base is one of the things I use the most. Speed 1 is for delicate stuff or when you don’t want to strip screws, Speed 2 is the general-purpose setting, and Speed 3 is basically “send it” mode. I like having a physical switch instead of going through some weird electronic mode button. You can feel the difference between each mode, especially when driving longer screws or working with metal fasteners.

The triple LED ring around the chuck is honestly more useful than I expected. It lights the work area evenly, not just from one side. In dim corners, under sinks, or inside cabinets, you can clearly see the screw head without your own hand casting a big shadow. There’s no separate on/off for the light, it just comes on with the trigger, which is fine.

Controls are simple: variable-speed trigger, forward/reverse/lock switch, and the speed selector. No silly extra modes or screens. One minor downside: there’s no bit holder on the base, and no bit included. Would have been nice to have at least one basic PH2 or T25 in the box. The included belt clip is handy and can be mounted on either side, which I actually use a lot when I’m up on a ladder.

This is where you need to pay attention: the DCF845B is bare tool only. No battery in the box. The whole experience changes depending on whether you slap a small 2Ah compact pack on it or a bigger 5Ah or 6Ah pack. I’ve used it mostly with 2Ah and 4Ah DEWALT 20V MAX batteries I already had from another kit.

With a 2Ah battery, it stays very light and nimble, which is great for overhead work or working inside cabinets. For typical house jobs (assembling furniture, putting up shelves, a few dozen screws at a time), a single 2Ah pack is fine. I can usually get through a decent afternoon of mixed tasks without draining it completely. But if I start driving lots of long deck screws or structural screws, I can see the 2Ah pack dropping pretty fast.

On a 4Ah pack, the tool feels more balanced for heavier work and obviously runs longer. I did a small deck repair job with around 100–120 3.5" deck screws and some lag-style screws, and the 4Ah battery handled it without needing a swap. The trade-off is weight: it’s still manageable, but you do feel it more in the wrist after a while, especially if you’re not used to heavier tools.

There’s no battery gauge on the tool itself, so you rely on the indicator on the battery (if your pack has one). That’s a minor downside compared to some newer designs that integrate more feedback, but not a deal-breaker. My advice: if you’re buying into the DEWALT system just for this tool, budget for at least a 4Ah battery and a charger. The driver itself is efficient thanks to the brushless motor, but if you pair it with a tiny battery and push it hard, you’ll be swapping packs more often than you’d like.

Out of the box, the DCF845B feels solid. The housing is mostly metal with some plastic parts, and nothing feels loose or cheap. The chuck locks bits in firmly; I haven’t had a bit fall out on me yet. The forward/reverse switch has a nice click and doesn’t feel mushy. After several weekends of use, including a couple of accidental drops from about waist height onto plywood and concrete, it still works like day one and there’s no obvious play in the chuck or housing.

The brushless motor should help with long-term durability. Brushless generally means less wear and less heat, especially if you’re driving a lot of screws. I’ve pushed it pretty hard driving long screws into treated lumber, and while it gets warm, it hasn’t gotten to the point where I felt I needed to stop for cooling. No burning smell, no weird noises, which is always a good sign.

Now, to be fair, there are some mixed stories with DEWALT quality control in general. I saw one buyer mention a defective DEWALT cut-off tool right out of the box (not this driver, but same brand), which tells me that even big brands let some duds through. My own DCF845B had no issues out of the box, no wobble, no spindle play, and the LED lights and speed selector worked perfectly. If something was off, I’d notice it pretty quickly, especially chuck wobble or power loss.

For now, I’d say the durability feels pretty solid based on a few months of mixed use. The casing has a few scuffs from normal work, but nothing more. If you’re planning to use it daily on a professional crew, I can’t speak for multi-year abuse yet, but given the XR line’s reputation and the brushless motor, I’d expect it to hold up better than the cheaper brushed models. Just keep in mind: it’s still an electronic tool – don’t leave it soaking in rain or full of drywall dust without cleaning it.

On paper, this thing delivers up to 1,825 in-lbs of torque and 3,400 RPM. In practice, it feels strong enough for pretty much any household and light professional work. I’ve used it to drive 3" and 4" deck screws into pressure-treated lumber, lag-style structural screws into studs, and some stubborn Torx screws on a door hinge. On Speed 2 it handled all of that without bogging down. On Speed 3, it just hammers them in fast, almost too fast if you’re not careful.

One specific example: I had a T25 Torx screw that was half-stripped and stuck in an old door hinge. On Speed 1, it didn’t move at all. Switched to Speed 2, and it powered through and tightened it further, to the point that my bit finally gave out before the driver did. That tells me the torque is there; you just need decent bits that can keep up. It’s definitely not lacking power for its size.

The variable-speed trigger is smooth enough that you can feather it for more precise work, like installing cabinet hardware or smaller screws into softer wood. I usually keep it on Speed 1 or 2 for that, and it’s easy to avoid overdriving or stripping screws once you get used to it. If you jump straight to Speed 3, it’s very easy to sink screws too deep, so there’s a bit of a learning curve if you’re new to impact drivers.

Noise-wise, it’s an impact driver, so yeah, it’s loud. Not the worst I’ve used, but don’t expect quiet operation. For concrete or masonry, you’ll still want a hammer drill; this is not the tool for drilling into brick. But for wood framing, decking, furniture assembly, and basic auto work (like small bolts with the right adapters), the performance is more than enough. I’d say it’s strong enough for serious DIY and light pro work, but if you’re driving big structural fasteners all day, every day, you might want to pair it with bigger batteries and maybe a heavier-duty model.

In the box, you get exactly what the listing says: the impact driver and a belt clip. That’s it. No battery, no charger, no bag, no starter bit. It comes in a simple DEWALT cardboard box, nothing fancy, but it’s fine for storage if you don’t have a tool bag. If you were expecting a kit, you’ll be disappointed, but this is clearly aimed at people who already have the 20V MAX system.

The model is the DCF845B, part of the XR line, which is DEWALT’s more “pro” range with brushless motors. On paper you get up to 1,825 in-lbs of torque, up to 3,400 RPM, and 3 speed modes. There’s also the "Chip Ready" feature, meaning you can add a tracking chip (sold separately) and use their TOOL CONNECT app to track it on a jobsite. For a home user like me, that feature is pretty useless, but I can see why a company with lots of tools might care.

One thing I noticed right away is they list the maximum chuck size as 0.5 inches, but this is a ¼" hex quick-release chuck impact driver, not a drill. So don’t expect to jam a regular 1/2" drill bit straight in there. You’ll need hex-shank bits and drivers. If you’re moving from a regular drill/driver, factor in that you may need to buy a half-decent bit set too.

Overall, the presentation is very no-nonsense: it looks and feels like a professional tool, but the way it’s sold (bare tool, minimal extras) makes it pretty clear they assume you know what you’re buying. For someone starting from scratch, the lack of bits or a basic kit is a bit annoying, but not a deal-breaker if you plan ahead.