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We Bought the BLACK+DECKER 3-in-1 Battery-Powered Lawnmower – Here’s What You Need to Know

We have two tiny patches of grass that do not warrant a full-size lawnmower. A battery mower is ideal for this amount of grass so we went with this compact 3-in-1 mower by BLACK+DECKER. This review reveals what I like and don't like (it's not perfect by any stretch).

BLACK+DECKER 3-in-1 cordless lawnmower

UPDATE JUNE 14, 2022: We moved to a house with a larger patch of grass.  This BLACK+DECKER wasn’t doing the job so we upgraded to the CRAFTSMAN V20 Battery-Powered Mower.

We’ve used a landscaping service for years. We still do despite not having much grass in the front or backyard. They prune, mow and tidy our yard every couple of weeks.

In the interim, I like to keep what little grass we have trim. By little, I’m talking about 350 square feet of it in two small patches.

This is particularly true ever since we converted a boring patch of grass into a terrific grass patio lounge. Because that’s our main outdoor lounging area, we like to keep the grass looking decent.

Such small square footage does not require a full-size lawnmower. That’s more hassle than it’s worth. I certainly don’t want to mess around with cords. It takes more time unraveling the cord and setting it up than actually mowing the lawn.

That’s why I decided to go with a compact cordless lawnmower. In fact, the more compact the better.

When we saw the battery-powered cordless BLACK+DECKER 3-in-1 Lawnmower, Trimmer and Edger in our local Rona store (Canada’s Home Depot), we had to give it a shot.

I’ve now mowed our two tiny patches of lawn 4 times with this cordless lawnmower.

This is my review of the BLACK+DECKER battery-powered 3-in-1 lawnmower.

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BLACK+DECKER 3-in-1 String Trimmer/Edger & Lawn Mower, 6.5-Amp, 12-Inch (MTE912)


  • Weight: 13.1 lbs.
  • Best for up to 750 sq. ft.
  • Power source: Lithium battery (comes with two batteries)
  • Battery charges to 100% in 4 hours / to 60% in 2.5 hours.
  • Grass cut length options: 1.6 to 2.4 inches.

Mowing quality

Here’s a photo of the grass freshly mowed with this mower. Notice how it’s a bit blotchy, which isn’t great but for us, it’s good enough.

grass mowed with BLACK+DECKER cordless mower

The quality of the cut is mediocre. Because it’s not a blade but instead an edging string (whipper snipper) that cuts the grass, you don’t get that smooth cut lawn look.

You also have to pass over grass more than once quite often.

It does not handle long grass well at all. In fact, if long, it will fold it over which is then difficult to cut on a second pass. I experienced this the first time I used it.

To solve this problem I make sure I mow regularly. It’s so light and easy to haul out that I can mow everything inside 15 minutes so it’s not much of an imposition.

As long as you use it regularly (as in before your grass gets long), it cuts decently.

Adjustable Height

BLACK+DECKER 3-in-1 cordless lawnmower adjustable height indicator

You can cut at 1.6 and 2.4 inches. We go with the 2.4-inch grass height.

Ease-of-Use (super lightweight)

This is where this mower really shines. It’s so light (13.1 lbs.) that I can maneuver it with one hand. The entire thing is plastic which means it’s not all that strong but the benefit is it’s lightweight which I love.

The trigger has a safety switch that you have to push before it starts up. It’s a bit of a nuisance but someone with young kids, I appreciate safety measures.

Converting it to a trimmer/edger from lawnmower is super simple. You simply step on the pedal and the main component lifts up from the mower body. Converting it back to a mower is just as simple – you snap it back into the mower body.


BLACK+DECKER 3-in-1 String Trimmer/Edger & Lawn Mower, 6.5-Amp, 12-Inch (MTE912)

While the photo shows it being powered by a cord, it is battery powered.

The edger/trimmer is released easily by stepping down on the pedal as shown below:

BLACK+DECKER cordless lawnmower pedal for releasing the trimmer/edger

BLACK+DECKER cordless lawnmower pedal for releasing the trimmer/edger

Because it cuts with a string inside a mower body, it doesn’t cut very close to the edges. Every time I mow, I pull it out of the mower body and use it as an edger.

As an edger/trimmer it works great. It cuts cleanly, quickly and it’s hard to argue with battery-power because there’s no cord to mess around with.

No trimmings catch-bag

There’s no bag to catch the trimmings which means they end up on the lawn. We don’t really care but if you don’t like your trimmings on the lawn, this is not the mower for you. There are other battery-powered lawnmowers with catch-bags.


While it’s powered by a battery, it makes roughly the same amount of noise as an electric trimmer/edger. It’s definitely less noisy than a gas-powered lawnmower and most electric lawnmowers.

Battery duration

BLACK+DECKER 3-in-1 cordless lawnmower battery attached to the mower

I love that it comes with 2 batteries so that one is always fully charged. I’ve not yet run out of battery but then it only takes 10 to 15 minutes to mow both small patches. BLACK+DECKER says it’s ideal for up to 750 sq. ft. of lawn so I suspect you can mow that much grass on one charge unless the grass is long.

As for charging duration, BLACK+DECKER reports it takes 4 hours to charge to 100% and 2.5 hours to charge to 60%. For us this is more than adequate since we can mow all our grass with one battery charge. I just rotate the batters in the charger after each mow so I always have a fully charged battery available.

It comes with a charger as well (it better, right?).

Easy to Store

Because it’s small and light, you can easily hang this on the wall. Remove the edger portion from the mower body and it’ll easy store on the wall and the small mower body can be stashed on a shelf.


Assembly was a breeze. You do need a screwdriver for one screw, but that’s it. The rest of it twists and clicks together. It took me under 10 minutes from the time I started tearing the box open to firing it up.

What I don’t like

I have two problems with this mower.

Trimmings gum it up quickly

Trimmings gum up BLACK+DECKER 3-in-1 cordless lawnmower so that it doesn't stay snapped together

First, trimmings gum up the mower body including the snap area where the edger clicks into the mower body. Once this happens, it won’t snap shut until you clean out the trimmings from the mower body. This happens fairly quickly. What ends up happening is the trimmer comes out of the body while mowing. It’s annoying.

Cuts with a String (Whipper Snipper)

BLACK+DECKER battery powered mower and edger string (view underneath)

Second, and I knew this when buying it because it cuts with a string, and that is the quality of the mowed lawn isn’t great. Long grass folds over. The cut isn’t uniform. You simply don’t get the same lawn look as you do with a blade.

Will I keep using it or buy a regular lawnmower?

Yes, I’ll keep using it for the convenience factor. Our landscaping service comes every two weeks to give our lawn a better mow but for interim mows, it’s great. The best feature is how easy it is to use and for me this counts for a lot.


Can you use BLACK+DECKER battery-powered mower on a slope?

Yes. In fact, it’s great for slopes because it’s so light. Our lower patch of grass is very, very steep. I’d be nervous using a huge mower but this is a breeze to use on the steep section.

Does it cut thick/long grass?

It does but it doesn’t do a very good job. At best, you’ll have to go over it two to three times. The best thing to do is use it regularly or in between a regular mow (like we do).