Kobalt 40-Volt Cordless Electric Lawn Mower in Seattle— A Three Year Review
In 2017 I purchased a Kobalt 40-Volt Brushless Lithium-Ion 20-in Deck Width Cordless Electric Push Lawn Mower from Lowe’s. Since that time, I have used that mower exclusively to mow my lawn in the suburbs of Seattle. There are a number of pros and cons with electric mowers as compared with gas mowers, and after 20 years in this house, I have owned more than one of each. Also, my father sent me to lawn mowing classes — a real thing — when I was twelve, and I have mowed more lawns than I care to remember. After using this mower for three years, I am sharing my personal experience with it.
In the positive column, electric mowers do not need gas or oil. You do not have to worry about the gas turning to varnish if you leave it in the tank over the winter. They literally start with the push of a button, and they are pretty quiet when compared to gas mowers. I own an electric car and I am biased towards the benefits of electric power tools. This particular mower has rechargeable batteries that can be taken out and shared with a whole line of trimmers, saws, a leaf blower, etc., so you don’t just get a mower, you get a battery system.
In the negative column, I have to add those same batteries that are in the positive column. Mowing in the Pacific Northwest is a little different than it is in many of the other parts of the country. Growing up in the Midwest, I was taught to never mow wet grass. Here in Seattle, we famously get rain about nine months of the year, and the grass stays green all winter, so mowing dry grass is not a luxury that we enjoy very often. The mower came with a 5 Ah battery. If the grass is bone-dry, the mower is set to its maximum height, and I have mowed my lawn within the last week, then I can just get my lawn mowed with one charge. For comparison, I have a weird, pie-shaped, quarter-acre lot in a cul de sac. If the lawn is wet at all — which is most of the year — or if it has been more than a week since I last mowed — or both — then I need multiple batteries.
Each power tool, such as the chainsaw or string trimmer, comes with a 2.5 Ah battery and I have a few of these tools. I usually start my mowing with an arm-full of batteries. I do as much as I can with the big battery, and then try to finish with the smaller ones. The 40-volt mower does not seem to have enough power to deal with wet grass, so even though it only has a 20-inch cutting path, I have to overlap each pass by about half, so I am effectively using a 10-inch mower. The low power also means that it has trouble throwing wet clippings into the bag, so I get lots of clumps of wet grass falling out on the ground. I just tried to mow my backyard and did not quite finish before running three batteries flat.
The final issue is what happens when you drain a battery. If the battery voltage drops too low, the battery charger will not recognize the battery. I put them on the charger and the light will not come on. I took two batteries back to the store and exchanged them because I thought that they were dead. Then two more batteries died, so I have “killed” four batteries in three years. I did a little YouTube searching and determined that I was not alone in experiencing this problem. It is possible to raise the voltage of the “dead” batteries to a point where the official charger will recognize them again. I am not an electrician so if you undertake that experiment you do it at your own risk, but I will say that I found that it worked for me.
With all things considered, I do recommend an electric mower, but not this one. It simply does not have enough power for anything except a small yard that is completely dry. Lowe’s should remove it from sale in the Pacific Northwest as it is a $400 mower that is not able to mow one, slightly damp, suburban yard, and the charger is, in my opinion, defective.