Smaller models from Kobalt offer high-value options for smaller lawns
Our recent best lawn mower reviews showed us a lot of what the market has to offer for both push and self-propelled lawn mower options. Kobalt offers two battery powered models for our competition. The 80V model finally won the cordless self-propelled category for its exceptional long run time, power and low noise level. The Kobalt 40V Cordless Lawn Mower performs similarly, but we found it to be a scaled-down version of the winner, aimed at homeowners with smaller lawns.
advantage
- Very quiet at 79 dB(A)
- Great value at $379
- steel deck
- easy to store vertically
shortcoming
- There is no battery level indicator on the lawn mower
- Short runtime due to smaller battery
Editor's note: Check out our best battery-operated lawn mowers article for our top picks.
Performance
cutting force
Cutting speed is important because the faster the blades spin, the easier it is for the mower to cut grass. As the grass gets thicker, the mower has to work harder to maintain the speed at the tip of the blade.
With battery-powered mowers, the brushless motor directs more power to the tip of the blade as the mower senses more resistance. So we looked at the tip speeds of all of our cordless lawn mowers — under light and heavy loads — to see which model performed best among cordless mowers.
To simulate normal weekly maintenance cuts, we tested the Kobalt 40V mower under a light load. Its 19-1/4" blade spins at 2780 RPM and translates to a 159.1 MPH blade tip speed. Sure, that's fast enough to cut through maintenance easily, but it's one of the slower models we've tested.
However, when we put the Kobalt 40V self-propelled mower under a heavier workload, we saw a 22.6 MPH increase in tip speed. As the mower feels more resistance, it increases power to 3174 RPM, or a blade tip speed of 181.7 MPH, for a moderately powerful finish.
If we only pull out the 40V class (36V/40V max), only Stihl can bring faster blade speeds when things get tough. It's a great company.
The cutting power of the Kobalt is standard on cordless lawn mowers. It handles your weekly cuts well and has the power to push extra days of growth. If you let your lawn grow much, you'll need to mow higher and back down, or cut off part of the lawn to get it back under control.
cutting area
While all this functionality is welcome, is it worth it if it costs you a fortune in terms of runtime? It really depends on the size of your lawn. In this particular case, you want to be able to mow about 1/4 of an acre on a single charge with the included 40V battery.
We got 32 minutes of runtime under maintenance load. If you're working on an overgrown lawn, that time can be shortened considerably. Set the drive to 2.5 MPH, or 11,293 square feet or 0.26 acres of cutting area. Uses only the batteries in the kit and is suitable for lawns 1/4 acre or smaller.
Of course, you can always buy extra batteries for longer run times.
noise level
Kobalt seems to be good at making quiet mowers. From a sound level standpoint, both models from the brand that entered our shootout performed very well.
The benefits of owning a quiet lawn mower are many. The quieter your lawn mower makes, the less you have to worry about damaging your hearing. That's why 79 dB(A) from the Kobalt 40V Cordless Lawn Mower is so good. 79 dB(A) is quiet enough that you won't even need ear protection according to OSHA standards.
Remember, this is a no-load test to see how much noise the mower is making by itself. Actual cutting, especially when the motor needs extra speed, creates more noise.
Even better, with the mower operating at this sound pressure level, you can run it early in the morning or late at night without disturbing your neighbors. I wish my neighbor — who thinks 6:45 am on a Saturday morning is the right time to start mowing — will hop on the cordless train.
feature set
adjustable self-propelled
Instead of using a pressure-sensing throttle, the Kobalt 40V mower opts for an adjustable lever throttle. The result is an easy-to-use, set-and-forget self-propelled drive method. Most of the time, we're happy when the mower does the tough work on its own, but when the system works like it does here, that's fine.
Some mowers start trying to move or even pace themselves. The better designs we've seen are on gas mowers, and the Kobalt's traditional approach has worked just fine for us.
steel deck
While some manufacturers opt for plastic decks, Kobalt uses traditional steel decks and 40V models. As Floridians who have to deal with a lot of sugar sand, we prefer steel because it is more resistant to wear and tear.
Height Adjustment and Range
The one-point cut height adjustment meant we only had to bend once instead of 4 times to adjust all four wheels. There are advantages and disadvantages to the single-point design. Overall, the Kobalt's steel deck keeps the frame strong, and we're glad to have that convenience. Some mowers use a single-point system to get loose.
When it comes to adjusting the cutting height, the Kobalt 40V mower gives you seven options ranging from 1.25 inches to 4.375 inches. This is a fairly broad range and should cover almost any grass species you have.
handle position
We all come in different shapes and sizes, so we appreciate when the mower lets us customize the handle position to accommodate different heights. The Kobalt 40V lawn mower gives us 3 working positions to choose from and an easy-fold handle that makes vertical storage a breeze.
discharge option
No matter what you want to do with your clippings, the Kobalt 40V lawn mower has you covered with mulching, bagging, or side discharge.
missing features
- No battery charge light on lawn mower
value
The Kobalt 40V self-propelled lawn mower delivers great value for money – the second best in its class. The only lawn mower that showed a better value (and a very slim margin) was the Greenworks 60V Lawn Mower.
It retails for $379 at your local Lowe's or online and comes with a 40V 5.0Ah battery and charger.
Of course, we look at factors other than price when considering value scores. Build quality and warranty also matter. We love the overall build quality of this Kobalt model, and the 5-year warranty that comes with this mower convinces us that Kobalt thinks they've put together a very solid mower as well.
Additionally, the Kobalt 40V line includes this lawn mower, chainsaw, blower, cord trimmer, hedge trimmer, chainsaw, and snow blower. If you decide to invest in the brand's 40V series of OPE tools, this mower offers an affordable option.
the bottom line
The self-propelled version of the Kobalt 40V Lawn Mower does a great job for homeowners who maintain their lawns. It doesn't have the cutting ability and runtime that some of the higher voltages have. But it makes up for it with quiet operation and a great price for bargain hunters.
Choose this if your lawn is 1/4 acre or smaller and you rarely go more than a week between mowings during peak growing season.
Kobalt 40V Lawn Mower Manufacturer Specifications
- Model: KMP 5040-06
- Cutting Tape: 19.5″
- Deck Type: Steel
- Deck Adjustment: Single Lever
- Cutting height adjustment: 7 positions
- Cutting height range: 1.38″ – 3.75″
- – Bagging machine included: Yes
- Brushless Motor: Yes
- Battery Amp Hours: 5 Ah
- Charging time: 2.5 hours
- Cutting range: 1/4 acre to 1/2 acre
- Drive Type: Rear Wheel Drive
- Assembled Weight: 65 lbs
- Discharge position: side and rear
- Warranty: 5-year limited
- Price: $299 at Lowe's