Home lawns are here to stay, especially in the rainier parts of the country. In the drier West, home lawns are smaller, but there are still plenty of them. So no matter where you live, it is likely you'll need some type of lawn mower now or in the future.
Most Americans use some variation of the walk-behind, rotary power mower. Despite many improvements, mower design hasn't changed in nearly 60 years: a gasoline engine spins a metal blade that cuts the grass.
Although manufacturers have made heroic efforts to clean up gasoline engines (the newest mowers don't pollute nearly as much as older ones), they remain among the dirtiest tools gardeners use. According to one study, one older lawn mower pollutes as much as three cars. Add to this some increasingly restrictive state and federal emissions regulations, and you have a demand for innovation.
Corded electric mowers always had their champions, but the limitation of cord length precluded broad consumer acceptance. Corded mowers also included the dangerous potential for cut cords.
Enter the new cordless electric mowers. These mowers are far quieter than the gasoline-powered ones. Also, battery-powered mowers start with a switch, not a pull-cord, and there's no balky engine to coax to life.
We were impressed by an extensive study that compared gasoline to cordless electric mowers. Funded by the EPA, the Electric Power Research Institute (EPRI), and the Edison Electric Institute (EEI), researchers found that 90 percent of the home gardeners they enlisted to test cordless electric mowers would recommend them to a friend or relative.
Perhaps the best feature of these mowers is their minimal environmental impact. Even after accounting for power-plant emissions, replacing gas mowers with electrics results in a 99 percent reduction in carbon monoxide, hydrocarbons, nitrogen oxides, and methane, and a 38 percent reduction in carbon dioxide.
Have you ever felt a twinge of guilt when your gasoline-powered mower first roars--those of us with nearby neighbors have. Or have you waited until you knew your neighbors were up and about before mowing the lawn? Gas mowers run at some 90 decibels (ear-protectors are recommended for operators), and normal conversation about 75 decibels. Electric mowers, operating in the 65- to 85-decibel range, make being a thoughtful neighbor a whole lot easier.
Although the typical lawn won't pose any problems for these mowers, assess your situation before investing. Cordless electric mowers are best for flat lawns that are smaller than 10,000 square feet and composed of cool-season grasses such as Kentucky bluegrass, fine and tall fescues, and perennial ryegrasses.
These mowers can also be hard to push up sloping lawns. Although they're not heavy in comparison to standard mowers, only the Ryobi among the cordless electric rotary mowers is self-propelled.
The more power required, the less time batteries last. For example, if your lawn is lush and thick, or if you let it grow tall before mowing, assume batteries will last for 5,000 square feet or so. If your lawn is easier to mow, most cordless electrics can handle up to 10,000 square feet of lawn.
If you have Bermuda or St. Augustine grass, and prefer a short, manicured cut, the McLane 20-EC is your best option. Battery-powered and self-propelled, it is also the only reel-type mower in this group.
Cordless electrics use only $3 or $4 of electricity a year, about what you spend using a toaster for the same period. Gasoline mowers cost $20 to $30 a year in gas and oil. Tune-ups cost from $50 to $200. Even when you also figure the cost of battery replacement every 5 to 7 years, cordless electrics can still cost one-third less than gas mowers in annual expenses.
Batteries and Power. Cordless mowers gener come with one to three 12-volt, lead-acid batteries (12-, 24-, and 36-volt models). The two Lawnboy cordless electric mowers have 6-volt batteries. But the actual voltage (or power) delivered to the motor depends on amperage. For example, a 12-volt mower with high amperage can mow longer than a 36-volt mower with low amps.
Power is a function of battery type, blade and deck design, and power transfer. All manufacturers exploit computer-aided design techniques to optimize blades' weight and shape and decks' contours. Toro and Black & Decker claim that their cordless mowers have more torque than a 5-horsepower gas engine.
Ryobi, Toro, Black & Decker, and Sears build the recharger into the mower, which simplifies recharging: You simply plug the mower into the wall with an extension or provided cord.
It takes between 12 and 24 hours (overnight) to fully charge most mowers, though a 3-hour charge will give you about 20 to 30 minutes of cutting time. Expect the batteries to last about 5 to 7 years. Ask dealers about the cost of replacement battery packs; costs vary from $60 to $200 each.
Batteries might lose power when they're stored for a long time. To store most models during winter where temperatures fall below 40oF., charge the battery overnight, then disconnect the mower from the charger until the next mowing season (up to 6 months). If temperatures generally stay above 40oF. where you live, leave the battery connected or plugged in year-round. However, check the owner's manual for specific storage directions.
Run time. Manufacturers' "run time" numbers are only estimates. How long a machine will run depends on the height and texture of the grass, moisture levels, and the terrain. Cutting relatively dry lawns takes a lot less energy than cutting lush, wet turf. Also keep in mind that all but two of the cordless electrics listed in the chart are push-types, not self-propelled.
As a general rule, if amperage is equal, 12-volt batteries provide 30 to 40 minutes of mowing time; 24-volt mowers last 40 to 75 minutes; and 36-volt mowers run for up to 90 minutes.
Recharging systems vary by model. Some mowers come with a separate recharger, a device that stays plugged into an outlet, into which you place the battery pack for recharging. For instance, the Yard-Man 798 comes with two 12-volt batteries, but the mower works with only one at a time. One battery stays on the recharger while the other one is in use. Two others, the Snapper BP1800 and the Husqvarna 43RC come with a similar, separate recharger, but the second battery pack is not included. To improve battery longevity, keep the blade sharp, and avoid low cutting by raising the blade on adjustable models.
Weight. Most of the models in the chart weigh between 46 and 85 pounds (not including the 140-pound McLane 20-EC). Battery-powered mowers weigh less than typical gas-powered mowers, but only two, the Ryobi BMD2418 and the McLane, are self-propelled. Even the comparatively light 75-pound electric feels heavy if you're pushing it up a hill.
Swath. The deck sizes vary from 16 to 20 inches on the mowers in our chart. Only the Sears Craftsman at 20 inches comes close to a typical gas-engine mower. This means that if you mow your lawn in about 40 minutes with a 21-inch gas-powered mower, it will take perhaps another 5 to 10 minutes with a narrower one.
Special features. Almost all of the models available as the article is written in January, 1997, come with rechargers included in the purchase price. Mowers without rechargers must be plugged into a wall when you have to recharge their batteries. Most have power gauges that show the charge level, so you know how much power (and mowing time) may be left before the battery needs another charge.
Decide which features make sense for your lawn and preferences. And if cleaner air and quieter mowing are also priorities for you, the cordless electrics may be the way to go when you buy your mower.
Article published on June 23, 2008.