When DeWalt’s first 12” double-bevel sliding compound miter saw came on the market, one of the guys on my crew bought one immediately. The price tag on the DWS780 was tough to swallow at first, but its versatility has paid for itself throughout the years. Since then we’ve purchased a new version which had some nice upgrades, and we still have the original. Tools of the Trade asked us several months ago to test out DeWalt’s latest iteration of the saw, the DHS790AT2: a cordless version that’s identical in specs to the DWS780 except it runs on a brushless motor powered by either 2 FlexVolt 60V Max batteries, or a power adapter. This kit we tested comes with 2 FlexVolt batteries, a dual-port fast charger, and 120V Max corded power supply. This part is a real game changer: a cordless saw that functions exactly as the corded DWS780, and has the capability of being cordless or corded.

Real-World Testing
The first challenge my guys put this saw to was building a playhouse for a local charity event. We had to build the structure in a field away from a reliable power source, which required using as much cordless equipment we could put our hands on (because, well, we didn’t want to have to listen to a generator if we didn’t have to). Most of the frame work for the playhouse was either full-dimension rough-sawn lumber or Douglas fir 4x4’s. DeWalt says that on a set of fully-charged batteries, the saw can make 250 cuts in 2x4s. We didn’t keep careful count, and we were cutting slightly heavier material than a standard 2x4, but we were pleasantly surprised by the saw’s runtime. One of my guys even commented halfway through the day, “This thing is like the Energizer bunny: it keeps going and going...” The batteries did eventually drain fully, but we made an awful lot of sawdust beforehand.

We do a lot of timberwork, so we also work with larger 6x material. Again, we got through a lot of lumber with two fully-charged batteries. But what we really liked about this saw is the fact that it can also be plugged in as well. So if you’re desperate and there’s power available, you can convert back to AC while the batteries charge. We had to do this a couple of times and though it required we move the saw temporarily, it was nice to have the option. With regard to battery life, we learned that if you put two batteries in that are depleted to different levels, the saw will only run to the battery with the least amount of charge left. The dual-port charger reportedly charges both batteries in 90 minutes, which seemed accurate to us.

The saw has the same features as the DWS780: 11 detents for setting the miter angle, and several options for setting positive stops for bevels, has a vertical cut capacity of 6-3/4” on base and 7-1/2” nested crown. The overall depth of cut for larger material is 4-7/8” so you can get through most of a 6x6 in one cut. One thing that we have been wanting in a miter saw but haven’t seen yet is the ability to fine-tune an angle even after it’s locked; locking an angle in even between the detents and then micro-adjusting it would be nice – but that’s getting a little picky and more of an issue around miter saws as a whole. The miter detent override lever is a nice feature – we used it often when running trim. Bevel adjustments on this saw are also nice and include the ability to go just beyond 45° to about 50°, which is great on things like outside corners when doing crown. The bevel adjustment comes with two “pawls” that swivel out on each side – one for 22.5° and the other for 33.9°; according to the handbook the pawls are preset from the factory for use with typical crown in North America (52/38) but you can reverse the pawls too for non-typical 45/45 crown. We cut crown both on the flat and nested – and found the saw accurate in both positions. In fact, we preferred cutting larger crown on the flat and the saw performed well in this scenario. Typically we’re cutting pre-primed pine and poplar. We had no deflection issues with the poplar, though didn’t cut anything harder than that. The corded DWS780 has done well for us with hardwoods, so I assume this saw would as well.

The saw has the capacity to cut up to 16” wide material. It requires removing the fences and adding a sacrificial 1 ½” platform to the saw’s table. We didn’t test this out – but it’s a good feature to have. We were also impressed with the saw’s dust-collection, which performed well for us – in both corded and cordless modes. The saw comes equipped with DeWalt’s FlexVolt 60T blade. DeWalt says that the blade is designed specifically for this FlexVolt saw to garner more runtime – it’s specially coated and sized – so you’re supposed to get more runtime out of it than if you used a traditional blade. We can’t comment on whether that’s true or not – because we didn’t try it. But we were happy with the blade’s performance and cut quality, as well as the saw’s overall runtime. It was cutting square to the fence right out of the box, though we had to adjust the bevel stops slightly – which was easy to do.

One small gripe we had was the depth-stop. We had to make a lot of shallow cheek cuts in 6x6s. This required that we lengthen the depth-stop screw close to its limit. When the depth stop arm was flipped out, however, the screw missed it. Our work-around required us to clamp a block to the area just above the depth-stop. Making shallow cuts in a 6x6 isn’t a common task, so it’s not a deal-breaker for us. But I thought I should mention it for those of you who do similar work. We felt like it didn’t have the same range as the depth stop on the corded version.

My only other criticism relates to the saw’s light, which projects a shadow line of the sawblade onto the work surface. This isn’t a new feature – it’s on previous DeWalt miter saws. On the corded model we own, there’s a switch for keeping the light on all the time. There’s a switch on the cordless version too, but it only keeps the light on for about 30 seconds. The light comes on when the trigger is pulled as well, but you have to lower the blade down to the work surface to get an accurate read. Because the saw has a good amount of kick, if you’re not careful you can accidentally catch the material before you’re ready to cut. We wished there was a switch on the front of the saw’s handle that made the light go on as soon as you pressed your palm up against it. This way you can have the light on without having to press a button or engage the motor – and you’re not depleting the battery by keeping it on all the time.

Bottom Line
The saw is available in three configurations: the DHS790AT2, which we tested, comes with two batteries, a dual-port charger, a corded power supply, dust bag, blade wrench, and 12” blade and sells for $800. That’s a big investment, but if you’re already leaning towards the FlexVolt line or are already invested in 20Vmax tools, and you need a saw this size, it’s definitely worth considering. The DHS790T2 comes with everything except the corded power supply and sells for $750. The DHS790AB kit comes with the power adapter, but not the batteries or charger and sells for $649. You can buy the corded power supply for $50 online. By comparison, the DWS780 sells for $600. Even if you don’t want to pony up the $800 for the full kit, if you’re thinking about the DWS780, it makes sense to splurge the extra $50 so you have the ability to go cordless down the road if you want to.