I’ve been trying to mow my yard with the new 21.5″ deck Dewalt 2x20V brushless push mower (DCMWP233) since April, but Mother Nature hasn’t been cooperating. Up until a month ago, I had only been able to use it 4 or 5 times because of the drought. It has only been the last few weeks that I’ve really been able to test it under relatively normal circumstances.
I reviewed the previous version of Dewalt’s cordless mower back in 2018, and I’ll refer to some of the differences later in this post, but first let’s start with the relevant specs of this mower.
Dewalt Cordless Mower Features & Specs
- Push mower
- 21.5″ metal deck
- 21″ cutting width
- 1-1/4″ to 3-3/4″ cutting height
- Brushless direct drive motor
- Requires (2) 20V Max batteries
- Kit comes with (2) 10Ah batteries
- 75 minutes runtime (2x 10Ah at max cutting height)
- Mulching, bagging, and side discharge
- 2 position handle
- Folds for compact storage
- Two lever 6-position deck height adjustment
- 3 year warranty
One interesting feature is the auto sensing technology Dewalt uses for the blade speed. The mower senses when the grass is thicker and increases the blade RPM. As far as I can tell, there are only two speeds: low and high. This is presumably done to eke out more battery life. The mower stays in low speed when you are positioning it for the next row, or are in an area with sparser grass and high speed only when needed in thicker grass.
This push mower is regularly sold for $399, but I’ve see it marked down several times this summer. It comes with (2) 10.0Ah 20V Max batteries (DCB210), (2) 20V Max 1.25 amp chargers (DCB107), a collection bag, side discharge chute, safety key, and instruction manual.
Cable Management Issues
Right off the bat, I had issues with the handle pinching the cable as it’s being folded open from its storage position.
I later discovered a second way that I could pinch the cable in the handle when folding it down for storage. On Dewalt’s previous 2x20V Max mower, they had a similar cable pinching problem, so you’d think they would have found a better way to run the cable.
This mower has a new safety feature in addition to the safety key and strict starting sequence — a switch that doesn’t let you start the mower when the handle is folded closed. Above you can see the actuation lever that the handle presses into the switch body when it folds down.
I’m not sure if there’s a new safety regulation that covers this type of switch, but it seems redundant. It is pretty unlikely that you are going to accidentally press down the button on the handle and push down the bail accidentally when the handle is folded. And if you are worried about it, just remove the safety key.
Blade and Deck Size
Dewalt is calling this a 21.5″ mower. The mower deck measures slightly over 22″ on the outside and slightly under 21.5″ inside because there is a folded lip. The actual blade itself measures 20.75″.
I’m still not pleased about companies using deck size to sell their electric mowers while they use cutting width to measure their gas mowers, but Dewalt seems like they are meeting us halfway with this mower. They easily could have called this a 22″ deck, but yet they choose 21.5″ and put in a blade very close to 21″.
Stuart’s Note: We inquired about this, and apparently it has become the industry’s de-facto standard for cordless mowers to be advertised by their deck size. So, when comparing cordless mowers, you have to look up the blade size in order to make apples-to-apples comparisons between different models’ cutting widths.
As you can see in the above photo, the blade is made by MTD — which is no surprise because that’s who makes this mower for Dewalt (which is now owned by Stanley Black and Decker).
The blade has a very curious design. Only 1-1/2″ at the tips of the blade actually cut at the set height. The rest of the cutting edge leaves the grass 1/2″ longer.
What’s more is that the blade has a proprietary connection to the mower shaft. It does prevent you from installing the mower blade upside down (which I have in fact done on another mower), but at the same time I can’t find any local sources for compatible MTD or aftermarket replacement blades. I can only find a replacement blade on the MTD part website. This could be an issue if you damage you blade and can’t mow you lawn for a few days minimum.
Update: Home Depot also carries the replacement blade (online only so far), with part number DWO1DT233. The same replacement blade fits this mower (DCMWP233) and the new self-propelled mower as well (DCMWSP244).
As I mentioned before, the mower runs at two different speeds. I measured the noise at each speed level and found sound pressure levels to be 73.5 dBA for low speed and 77.3 dBA for high speed. It has been pointed out to me that dBC might be more appropriate for a lawn mower than creates noise on the low end of the audio spectrum, but this is the sound level meter I have and used for other reviews.
Further supporting that this is probably the wrong scale, even though the SPL meter says it is quieter than the Ego LM2101, I cannot comfortably listen to music using over-the-ear headphones using the Dewalt mower, while I can with the “louder” Ego.
Still, this is quieter than any gas mower. People have walked by and commented that they are amazed at how quiet this mower it, just about every time I used it.
Charging and Battery Runtime
Dewalt supplies two 1.25A chargers with this mower to charge the two included 10Ah batteries. If you do the math, 10Ah / 1.25A = 8h charge time if the batteries are fully drained. So if for some reason you can’t fully mow your “up to 1/2 acre” property on one charge, you’ll have to wait 8 hours to finish mowing.
There is no external battery gauge on this mower to tell you the charge state of the batteries, there is only a warning light that is supposed to come on when the batteries are low. I only saw the battery warning light come on after I stopped the mower, which I did because I noticed the mower speed audibly slowing.
The lack of a battery gauge is kind of annoying, but on the previous Dewalt mower I found the mower battery gauge and the gauge on the batteries did not match anyway.
The battery compartment is large enough to fit the 9Ah FlexVolt batteries I have, which means the 12Ah ones should also fit. I’m not sure if the larger 15Ah FlexVolt batteries will fit though.
I found that my yard (a little less than 1/4 acre) isn’t large enough to fully exhaust the batteries. In a span of a few weeks I ran the battery down after 82 minutes. I mowed my entire yard in 44 minutes one time, and spot mowed 38 minutes over a period of 3 weeks because my grass wasn’t growing consistently in the drought. Now that we have been getting consistent rain, I have found that I can mow my entire yard twice using the included batteries. This actually meshes with Dewalt’s claim that the mower is “perfect for properties up to 1/2 acre.”
I have also tried mowing with 9Ah FlexVolt batteries and I really can’t tell any difference between the two sets of batteries.
Side Discharge, Bagging
The mower comes with a detachable side discharge chute. To attach it, you lift up on the spring-loaded plastic cover on the right side of the mower and hook the tabs of the chute under the hinge bar. When you let the spring-loaded cover back down it holds the chute in place.
Once I discovered that the mower performed better using the side chute than mulching, I started using the side chute more. Unfortunately because of the drought this summer, I don’t have any really thick wet grass to test how well the mower throws or if it spreads the grass evenly.
To install the bag, you lift the spring-loaded rear lid of the mower. There’s no plug to remove, because the plug is built right into the lid. With the door open, the bag drops into place on a nice curved “track.” Then the rear lid swings down and seals over the bag to keep it in place.
Once again the cable likes to get in the way. I had to move it many times to get the bag to drop into place.
Even when the mower is running in low speed, it throws the clippings into the bag pretty well. It’s impossible to see, but there is only a small area in the back that where the grass isn’t filled as high. It’s not perfect, but more acceptable than some other mowers I’ve owned that filled the front of the bag first and prematurely blocked the clippings from entering the rear of the bag.
I like the new bag design. It has a single-piece plastic bottom. The previous Dewalt mower had a fabric-over-plastic bottom. With the old design, dust would accumulate between the layers, and so the empty bag gets heavier and heavier over time with no easy way to remove the dust.
First off, it is really hard to photograph grass, but I think I was able to capture it well enough to get my point across.
This is the worst mulching cut quality, at the lowest blade height, I’ve seen from any mower. Above is a section of my lawn after cutting at height 2. It may look like I didn’t overlap the rows enough, but I assure you I overlapped the cuts by several inches at least. After discovering this, I pulled out my Ego mower, set it to the same height, and mulched — while it wasn’t perfect it was way better.
Most of my yard is thin bladed fescue, and I’ve always had issue with my grass flopping over. Even with a prosumer Toro, once I raised the deck to the upper 50% of cut height, it would leave some grass uncut. I noticed this somewhat with the previous Dewalt mower and my Ego when I started raising the deck, just like the gas mower. But this Dewalt mower, in default mulching mode on height 2, is leaving significantly more of my lawn uncut.
After further testing I discovered that cutting with the side discharge chute or with the bag attached, the mower cut the grass significantly better. So it is just the mulching performance on thin grass that is terrible.
We’re going to need to step back here and discuss mulching. I’ve been mulching my lawn ever since I bought a mower with no side discharge chute. Several mowers now don’t even have the option of not mulching if you are not bagging. This mower is set up out of the box to operate in mulching mode, with no instructions on why you’d want to use each mode. Most people don’t think about how they are going to set up their mower, they pick a setting and use it like that every week.
Mulching recirculates the grass under the mower so it gets cut up into tiny little pieces, hopefully small enough so they don’t clump. In a mulching mower, the blade is designed so that air flows up around the outer perimeter of the deck to pull grass to the top of the deck. Then the grass falls back down in the middle to get cut again. When you use side discharge or bagging, the grass gets pulled up and then directed towards the outlet, getting cut only once.
I believe the reason I’m seeing better performance is that when you have an outlet, there is stronger/more directed air flow that helps pick up the grass, vs the more turbulent airflow when mulching that doesn’t lift the grass as well.
I think there are two issues: the cutting speed and the blade design. The mower is hardly ever kicking into the high speed cutting mode, which would generate a little more lift and more cuts at the same walking speed. Second, looking at the blade design, very little of the blade is actually cutting at the finished height. It is getting cut at an intermediate height first and then this shorter grass may be getting knocked over easier, missing the final cutting height.
When I mulch cut a section of my grass that is mostly thicker grass and weeds, but still a little sparse and I get a pretty consistent cut. Meaning, users with thicker lawns will probably see better results.
I understand that the blade design and dual cutting speeds are done to extend the battery life, but I think they over-emphasized the battery economy in this case. The problem is that this mower has been so optimized for battery life, the mulching just doesn’t have a strong enough lift for thinner grasses. But then again, if the grass is so thin that mulching doesn’t work well, you probably don’t need to be mulching in the first place.
Why is this an issue? People are going to get upset when the mower doesn’t perform equally well on all parts of their lawn or under changing conditions. Most users are going to set the cutting height and the mowing mode one time (except maybe for bagging). Once they get the mower set to where it performs to their liking, they’ll never think about it again. Who is going to waste precious cognitive power trying to figure out what the proper settings are for each time they mow the same lawn, when they could be daydreaming about new tools instead?
I did not actually measure the temperature of the batteries because I never had an issue with them overheating. At their worst, the 10Ah batteries were barely warm to the touch.
I did stall the mower a few times, not that it was really the mower’s fault. I don’t always clean up the sticks in my yard and a few times one would get jammed and stop the blade. When this happens, I just let go of the mower, restart it, and keep on mowing.
I do not understand why Dewalt got rid of the single lever height adjustment in favor of the two lever height adjustment: one for the front and one for the rear. While this is still better than having adjustment levers for each wheel, the single lever is very nice for people who mow their backyard on a lower setting than the rest of their yard, such as for dog poop to be more visible.
I wish Dewalt would have made the running speed adjustable — after all, most gas mowers have a throttle speed. Hypothetically, such a lever could offer several speed settings between the mower’s out-of-box low and high running speeds. The mower could still sense the cutting resistance and automatically boost the running speed, but you would still be able to speed it all the way up to mow problem areas or slow it down when you wanted to maximize battery life.
Before I summarize my observations and thoughts about Dewalt’s new cordless push mower so far, I’d like to restate the major limitation with this review. My area of the country was under drought conditions for most of the summer, and so I don’t feel I was able to fully test the mower under normal summer conditions with healthy well-hydrated grass.
It’s a given that a battery-power mower is not going to have the same cutting ability or lift as a gas lawnmower, especially one that has been optimized for battery life. That said, I’m still pretty disappointed with the mulching cut quality in my yard. The cut quality while using the bag or the side discharge chute was good, I found it to be closer to the Ego LM2101 or previous Dewalt mower while mulching. Bagging performance was also adequate with grass clippings and a few early leaves.
This mower is priced to compete. At $399, not only do you get over an hour of runtime, but you get 2x 10Ah batteries. If you were to buy similar batteries separately, it would cost you somewhere between $300 and $350. Even a pair of 9Ah Flexvolt batteries will cost you over $300. So basically you are getting high-capacity Dewalt batteries and having a lawn mower thrown in for a few extra dollars.
Should you buy this mower? Again it’s a hell of a bargain if you take the batteries into account and you don’t try to mulch a sparse, thin grass yard. I did not have a good experience using the mower on thin grass in mulching mode, but as long as you bag or use the side discharge shoot, or have a thicker variety of grass that doesn’t need much lift to be cut, it may be worth looking into.
Dewalt also has a self-propelled version of this mower that’s currently priced at $479 via Home Depot.
Thank you Dewalt for providing the test sample used in this review.