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BLACK+DECKER CM2040 40V Lithium 3-in-1 Cordless Mower, 20"
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- Includes (2) 2.5Ah - 40V MAX Lithium Batteries for longer cutting time
- 20-inch wide cutting path
- 6-setting height adjustment from 1-1/2 inch to 4 Inch high
- 15 gallon nylon grass collection bag
- Note: Please refer the installation manual for using the clip and the user manual for charging the CM2040 battery
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From the manufacturer
What's in the box:
- CM2040 20" Mower
- (2) 2.5Ah - 40V MAX Lithium Batteries
- (1) Grass Bag
- (1) Charger
BLACK+DECKER Lithium 3-in-1 Cordless Mower
Packed with two 40V MAX lithium batteries, this 20-inch cordless mower has the power and runtime you need to tackle tough mowing. Features convenient 3-in-1 mulching, bagging, and side discharge. EDGEMAX provides up-to-the edge cutting.
- 20" 3-in-1 mower - mulching, bagging, or side discharging.
- Variable Speed Motor allows conserving the battery for greater efficiency and runtime.
- 15 gallon nylon bag allows checking fill levels.
- 6-setting height adjust- Single level easily adjusts the height of cut between 1 1/2"-4" to cut all types of grass in the US.
AutoSense Technology determines the thickness of grass and makes power adjustments accordingly. For thicker grass, the mowers kick into high power while in lighter grass, the mowers lower the power output to conserve battery life and extend runtime.
With convenient 3-in-1 mulching and bagging, the 20-inch also features EDGEMAX which provides up-to-the edge cutting.
40V MAX Lithium Ion Batteries
The mower comes with two batteries, for double the runtime. When not in use, the extra battery can be stored in a convenient compartment on the top of the mower. The extra battery also provides a backup that can be used with the system of 40V MAX Black+Decker lawn & garden tools.
Since 1910, BLACK+DECKER has been setting the standard for innovation and design of power tools, outdoor yard care equipment, and home products. The inventor of the first portable electric drill with pistol grip and trigger switch, BLACK+DECKER has evolved from a small machine shop in Baltimore, Maryland to a global manufacturing powerhouse with a broad line of quality products used in and around the home. When home owners have work to get done, they trust that BLACK+DECKER’s products will do the job efficiently and reliably.
|Cutting width||20 inches|
|Item Dimensions||21.88 x 16.81 x 34.88 inches|
|Item Weight||59.5 pounds|
|Manufacturer Part Number||CM2040|
|Manufacturer Warranty Description||2 year limited manufacturer's warranty|
|Shipping Weight||57 pounds|
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|Item Dimensions||16.81 x 34.88 x 21.88 in||20.66 x 29.2 x 19.5 in||16.13 x 26.88 x 18 in||23.1 x 44.7 x 17.4 in||22.2 x 37.4 x 24.1 in||17.7 x 48.4 x 42.9 in|
|Item Weight||59.5 lbs||42.5 lbs||56 lbs||65.3 lbs||90 lbs||33 lbs|
The BLACK+DECKER CM2040 40v Lithium 3-in-1 Cordless Mower features (2) 2.5 Ah - 40V Max Lithium Batteries for 30-45 min of mowing time. This mower offers mulching, bagging and side discharge for multiple mowing modes. The variable speed motor allows conserving the battery for greater efficiency and runtime. The EdgeMax deck design allows cutting up to the edge of fencing and flower beds, providing a clean and manicured lawn fast. This mower also features a 20-inch wide cutting patch, with a 6-setting height adjustment that allows choosing the height of cut between 1-1/2 Inch to 4 Inch. It has a 15 gallon nylon collection bag that allows you to check fill levels. This mower is backed by BLACK+DECKER's 2 year limited warranty. What's included: (1) Mower, (2) 2.5Ah - 40V Max Lithium Batteries, (1) grass bag and (1) manual.
Top customer reviews
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There are some things about this mower that I like. It's light weight, maneuverable, quite and easy to store. It's arguably better than some older battery-powered electric mowers. It's a good match for you if you have a very small lawn. Most everyone else is likely to become very frustrated by the flaws and limitations of this model, and even if you like it at first you'll probably change your tune when it breaks... and when you discover that the batteries have a short life, a high failure rate and are IMPOSSIBLE to replace.
- The life of the batteries is HEAVILY dependent on how hard the mower has to work to cut your grass. If you have a thick, healthy lawn and you've allowed it to grow even a LITTLE bit long you are likely to exhaust the battery in as little as 8-10 minutes... IF you can get the mower to cut your grass at all without constantly stalling.
It's possible to nurse the thing along, but here's what that means in practical terms:
- You'll need to set the cutting height much higher than is ideal, probably so high that you'll need to mow your lawn twice to get it properly clipped... or mow 2-3 times per week to make sure the grass never gets tall enough to stall the electric motor.
- Every time you hit a patch that's even slightly thick you'll need to raise the height, push the mower VERY slowly, or cut significantly less than a full 20" swath at a time.
- Even after I figured out how to nurse the thing along in thick grass it still stalls a lot. I'm not talking about 6" tall grass either; just ordinary healthy grass in a cool, sunny climate... like spring here in central Virginia where we typically get plenty of rain alternating with cool, sunny days. I suspect that many of the buyers who give this mower a good rating live somewhere hot and dry where grass is thin, dry and doesn't grow very fast.
- You'd THINK that when the mower DOES stall you could just back up a couple steps and switch it back on again. But it doesn't work that way. Black & Decker has designed this mower with complicated, clever electronic sensor system with a mechanical "safety" interlock. This too-clever system kicks in every time you stall the electric mower, and it's REALLY FRUSTRATING because there's a VARIABLE DELAY that prevents you from quickly restarting the mower. At first you think the "go-control" is just an electric switch. If the mower stalls it's like a circuit breaker pops, so you'd expect to just be able to flip the switch back on. But you actually have to hold an orange safety button down while you pull the switch, and then you find the switch has been temporarily disabled and doesn't work. You have to release the bar on the handle (the switch), release the safety button, press the safety button again, and pull the bar again... and sometimes repeat this several times until the motor finally starts spinning again. It can be REALLY irritating because the delay is VARIABLE and there's no rhyme or reason to how long you have to wait before you can restart.
- There also appears to be a thermal cut-out. If the electric motor OR the battery gets even a little bit hot the whole thing stops working.
Which brings us to recharging the batteries:
- They don't last long if your grass is thick.
- And you can't just pop them back in the charger for a few minutes: you have to wait for them to cool down first, typically a 20 minute delay before they even START recharging, then recharging takes a LONG time, like more than 90 minutes. You typically need to allow 2+ hours for each battery for cool-down and recharge. And then when the battery comes out of the charger it will be warm, so it has somewhat reduced power and lasts an even shorter time than usual.
- Oh, and don't think you can speed up the process by putting the batteries in the fridge. These are some very picky batteries: being chilly ALSO prevents them from starting the recharge cycle.
How long do the batteries last before you have to replace them? Not long, it would seem. One of mine started dying after being recharged less than 10 times. It was probably defective... but that leads to another HUGE issue: You CAN'T BUY REPLACEMENT BATTERIES. At least not the high-capacity 2.5AH that ship with the CM2040. They simply are not available.
That's a big problem. AH, "Ampere Hours" is a measure of how much electric energy a battery can store. 2.5AH really isn't very much power relative to the demands of an electric mower. That's why the 2.5AH batteries shipped with this model run down in as little as 8 minutes. But if you try to replace the standard batteries or buy a spare you CAN'T BUY the 2.5AH version. Instead, the replacements they try to give you (for $70!!!) are only 1.5 or 2AH. Either one of those is TOTALLY inadequate for this mower.
The first CM2040 I received had only one battery (the other was missing from that box), and as mentioned above the single battery I received went defective within a couple days. While I waited for a replacement mower from Amazon (they were good about it as always, but see more about that below) my grass was growing, so I thought I'd buy a spare or two. No luck. I've pretty well established that the 2.5AH batteries SIMPLY ARE NOT SOLD as spares or replacements. B&D and Lowes both told be there IS no such part.
So how long will a lower-capacity battery last? As little as 6 minutes. Worthless.
A FEW MORE PROBLEMS
- The CM2040 was received with two little plastic cable clips broken. They are probably 50 cent parts and they would fit in an tiny envelope. But they are important, so I called Amazon to request replacements. "Sorry, we can't get replacement clips. We'll have to send you a new mower." Great customer service from Amazon, but WHAT A WASTE to ship and second 50# mower (and ship back the first one) just to replace a couple cheap, wimpy 50 cent plastic clips!
- The first mower was also shipped with only one of the 2 batteries. The replacement took care of that... but as mentioned above, by the time the replacement mower arrived I'd already had the single battery that came with the first mower FAIL.
Also in the first few days of use:
- The plastic knob on the height adjustment lever fell off.
- A plastic part on the mower's battery connector broke off, leaving the contacts exposed.
- The next time I inserted the battery in the mower one of the now-exposed contacts bent and broke, totally disabling the mower.
- The left front wheel had started to wobble and looked like it was about to fall off.
- The grass catcher basket was already starting to fit poorly and no longer had a snug fit, causing clippings to blow out around the edges.
Bottom line? I'm keeping the replacement because I really WANT to like this mower. But I have to go buy a new gas mower. The CM2040 is just too wimpy to be my only mower for a normal-size lawn. And I think it's rather obvious that if I use it frequently it won't last very long at all. I will use it only for a few areas where its light weight an easy handling make it easier to use than a gas mower.
Initial pros: lightweight, easy starting.
Initial cons: battery life, incomplete grass cutting
As I began to experiment with the batteries and equipment more and more, I came to realize the battery gets really hot powering the mower. When it's depleted it has to cool before it will recharge. I tried various methods to speed up this process ... even wrapping it up and putting it in the freezer for about 40 minutes. It seemed to speed up the cool down process, but now I just put the battery in the shade to let it cool down. Since the two 2.5 amp batteries and the one 2.0 amp battery I have are all interchangeable, I now begin by using a 2.5 battery with the trimmer and trim first. The trimmer doesn't heat the battery up like the mower, so when I'm finished with edging and trimming the front and backyards, that battery is immediately put back on the charger and begins charging. Then I'll grab the remaining 2.5 battery and put in the mower, and use the 2.0 when the first battery dies. Usually I'll throw in a few breaks during the work, and by the time I need the first battery I put back on the charger is sufficiently charged to complete the yard (including the blowing).
Now back to the incomplete cutting of the grass problem. I examined the grass still sticking up and found blade marks on the grass. So, I knew the blade was contacting the grass - just not completely cutting it. After a bit more thought I removed the battery and starting key so the mower couldn't energize, and flipped it over. Problem identified. Very dull blade, and I do mean VERY DULL. Looked like it had never been sharpened. Absolutely no danger of cutting yourself with that blade.Took it off, sharpened it, and put It back on. Works much better now. I've noticed it still misses a few blades of grass, but not any different than the previous gas mowers.
Final observations ... This mower isn't nearly as powerful as a gas mower. However, it is sufficient to cut this thick San Augustine grass. I actually like the finished look now ... the light weight of the mower doesn't leave the deep wheels tracks like the heavier mowers and tends to leave a nice smooth finish to the lawn. Using this mower with the other BD equipment I have and the additional battery has made this a workable situation for me. However, if you are in a big hurry and/or have a bigger yard, then you'll find this mower with its batteries to be a bit of challenge.