Israeli company Friendly Robotics makes the Robomower brand of robotic lawn mowers. These have excellent safety features and are the most popular robotic mowers in the United States. All Robomowers come with a two-year limited warranty: two years on parts and labor, one year on the battery (Robomower batteries are lead-acid, not Li-ion). The Robomower RM200 and RM 400 models can cut to a maximum height of 3.15 inches, the Robomower RL850 to 3.25 inches. Experts say that in hot climates, grass should be left at least 3 inches high to prevent lawn damage.
The Friendly Robotics Robomower RM200 (*Est. $900) is the least expensive model, designed to maintain small yards up to 2,700 square feet in size. You charge it indoors by plugging it into an outlet, and then carry the 39-pound mower to your perimeter wire's starting point. An optional remote control (*Est. $80) lets you drive the RM200 to its starting point rather than carry it. The Robomower RM200 robotic mower incorporates a rain sensor that lets it automatically shut itself down when precipitation is detected (both to protect the grass, which shouldn't be mowed when wet, and to minimize the chances that it will bog down in wet ground). The mower itself, like all robotic mowers, is weatherproof. The RM200 can handle slopes of up to 18 degrees, so it's best for flat lawns.
The Robomower RM200 is the least expensive robotic mower on the market. However, we couldn't find reviews for it. Even though it's sold online, user reviews are scarce.
Up a step from the RM200 is the Friendly Robotics Robomower RM400 (*Est. $1,000), which can mow lawns up to 4,300 square feet with up to an 18-degree grade. A charging station is included. Users can program the Robomower RM400 to leave the charging dock and do its job, then return -- without any lifting or remote-control guidance. If your lawn has narrow areas less than 6 feet wide, however, you'll need to guide the RM400 using the optional remote control. This robotic lawn mower is weatherproof, but its charging station isn't, so it must be kept in a dry place. Again, as with the RM200, objective reviews and even user reviews are practically nonexistent.
The Friendly Robotics Robomower RL850 (*Est. $1,600), like the RM200, plugs into a wall outlet and requires manual guidance at the beginning and end of each mowing session -- a remote control is included with this robotic lawn mower. Like the RM400, the Robomower RL850 is weatherproof. It has knobby wheels for traction and can handle a lawn of up to 10,700 square feet -- about a fourth of an acre -- and slopes of up to 15 degrees.
The Robomower RL850 is one of the few robotic mowers that gets coverage in reviews. It's clear that owners want to love it, and even those who ultimately give the RL850 a low rating admit that their lawn looks great -- when the mower is working. Several owners write long, detailed reviews explaining the litany of problems and repairs involving their RL850 mowers. But of the 30 reviews posted at Amazon.com, two-thirds are happy with the RL850. Most owners stress that it takes quite a while to get the Robomower set up -- that setting up the perimeter wire takes a long time, and even then, you may need to keep tweaking to get it right. Overall, owners say that the Robomower just isn't totally hands-off. One puts it well, saying that while it saves him work, it doesn't necessarily save him time.
LawnBott robotic mowers, made by the Italian company Zucchetti Ambrogio, are the quietest robotic mowers available. They use more sophisticated technology and continue to develop high-end features; online software updates are free. All LawnBott mowers work without manual assistance and automatically return to their base station whenever they need recharging; when recharged, they head back out to the lawn to finish mowing. They are also more expensive than Friendly Robotics Robomower models, and are harder to find in stores.
LawnBott mowers can detect the difference between grass and air, so they automatically lower blade speed when traveling across a paved area or an area where the grass has already been cut. This conserves battery power and lets them mow larger areas. When a LawnBott robotic mower encounters heavy grass that's harder to cut, it automatically alters its mowing pattern, working in a tight spiral, mowing harder until the resistance lessens.
The cheapest LawnBott model is the LB1200 Spyder (*Est. $1,400), which has limited availability in the United States. This model doesn't need a perimeter wire. However, your lawn must be bordered on all sides, so there needs to be a sidewalk, curb, planter boxes, gravel, bare dirt, etc. bordering the whole area you want to mow. You're just supposed to plop down the Spyder and watch it mow. The battery is rated to mow for about 2,200 square feet. We couldn't find any objective reviews on this model. But on Probotics.com, a retail website, editors say this isn't a good choice for patchy lawns, because the mower will only mow over living grass.
The Friendly Robotics Robomower RL1000 (*Est. $2,100) is the priciest Friendly Robotics mower, handling up to 17,200 square feet (more than a third of an acre). This robotic mower includes a charging station and, like the smaller, less powerful Robomower RM400, can be programmed to mow on a schedule. It leaves its charger without your guidance, does its mowing and returns to the dock when finished. If you've defined more than one area for the RL1000 to mow, however, you'll need to guide it to the other areas to get it started. Like other Friendly Robotics mowers, the Robomower RL1000 requires manual guidance (by remote control) in areas narrower than about 6 feet. It's best for flatter yards because it can only handle 15-degree slopes. Among the handful of reviews at Amazon.com, three complain that it broke down after three seasons -- right after the warranty period ended. Most of the other comments are similar to those about other Robomower models: Setting up the perimeter wire is a pain, but the quality of the cut grass is great.
The programmable LawnBott LB 2110 Professional (*Est. $2,300), is the only LawnBott that uses lead acid batteries rather than more environmentally friendly Li-ion batteries, and it handles slopes only up to 12 degrees. The LawnBott LB 2150 Professional (*Est. $2,600) upgrades to Li-ion power and can handle up to 27-degree slopes. The LawnBott LB 2110 and 2150 robotic mowers are designed for lawns up to about three-quarters of an acre. Owners can program them to handle three separate work areas, first mowing one, then recharging, then mowing the next. For 2009, the Professional models got a new chassis and more powerful wheel motors, along with redesigned wheels and treads for better traction. Retailer MowersDirect.com identifies these LawnBott models as best sellers, but there's no review posted for either of them. Nor could we find substantial user reviews.
The even more expensive LawnBott LB 3210 Evolution (*Est. $3,400) comes with standard spiked wheels, Li-ion batteries, and is self-programming. Owners tell the robotic mower the desired results (i.e. the height at which the grass should be cut), and the LawnBott LB 3210 Evolution continually reprograms itself to achieve them. It not only times its mowing schedule to maintain the preferred grass height, but optimizes its mowing pattern whenever it encounters a tough patch, going into a tight spiral until it encounters less resistance. The LawnBott LB 3210 is rated for lawn sizes up to 33,000 square feet, but adding a second Li-ion battery (*Est. $300) almost doubles its range to 1.25 acres. Alternatively, you can just buy the LawnBott LB 3250 (*Est. $3,700), which includes a pair of Li-ion batteries right out the box. Both 3200-series LawnBott robotic mowers are appropriate for hillier lawns of up to 27 degrees.
The bottom line? Because of their high prices, it's hard to make a great case for buying one. From the limited user reviews we found, it's clear that their geeky gadget appeal is a big selling factor. But especially for the more affordable models, they aren't trouble free. It takes time to set up the perimeter wire. And users report the same type of durability and repair issues we see for regular lawn mowers. Overall, most owners really want to like their robotic mowers, and pretty much everyone says they are a lot of fun: They enjoy sitting on the back porch and watching them wander around the yard. In fact, many owners give their robotic mowers names.