The most useful questions to ask before buying a robot mower cover lawn size, boundary wire, slope limits, the charging outlet, app features, ownership costs and safety. Check each answer against the spec sheet, not the marketing copy, and most mismatches show up before you pay.
The short answer
- Size: buy a model rated for an area 20 to 30 percent larger than your measured lawn.
- Boundary: confirm whether you need a wire, and who installs it.
- Slope: check the rating for your steepest area, not just the best case.
- Power and app: confirm the outlet reach, Wi-Fi needs, and theft protection.
Questions to ask before buying a robot mower: how big is your lawn?
The first of the questions to ask before buying a robot mower is size. Choose a model rated for an area at least 20 to 30 percent larger than your measured lawn, according to Sunseeker’s UK buying guide. The buffer covers narrow gaps, beds and other obstacles that slow a mower down and reduce real coverage.
Ratings are set by the manufacturer, and they differ by model. Husqvarna says its Automower range handles lawns “up to 5000 m2 +/- 20%, depending on model and complexity of the garden.” That is about 53,800 square feet, a figure we calculated from the metric number. For larger lawns, Husqvarna suggests running two or more machines side by side.
Our reading is that a lawn with many trees, flower beds or narrow passages should be treated as larger than its raw area. Measure the usable grass in square feet before you choose a robot mower by lawn size. A map estimate is a fair starting point, but it does not show slope or obstacles.
Do you need a boundary wire or a wire-free system?
Boundary wire is the next of the questions to ask before buying a robot mower. Most mowers without satellite navigation need a boundary wire, and Husqvarna puts installation at about 2 to 5 hours, depending on the size and complexity of the lawn. Its guide says installation is not included in the recommended retail price, so ask the seller whether setup is part of the purchase.
Husqvarna describes three options. The wire can lie on the surface held down with staples, or it can be buried at a depth of 3 to 10 cm. Some models offer a virtual boundary instead, and its X-line models use on-board GPS to simplify installation.
| Option | Setup | Main limit |
|---|---|---|
| Boundary wire | About 2 to 5 hours (Husqvarna); a wire and peg kit cost GBP 70 to 100 extra in a 2020 Which? article | Needs careful laying and staples |
| Virtual or GPS boundary | Set up in an app, with no digging | Depends on the model and its navigation |
| Wire-free RTK or similar | Set up through the app, according to vendor pages | Depends on a clear satellite signal, so ask the maker how the model copes under trees and near tall buildings |
Wire-free claims need checking. Mammotion says its wireless models avoid digging and perimeter wires, but that is a vendor claim. Ask for the navigation type in writing, then ask how the model behaves under the trees in your yard.
Can it handle your slopes and grass?
Slope is another of the questions to ask before buying a robot mower. Check the maximum slope rating for your steepest area, because a model can handle a gentle lawn and still fail on a bank. Husqvarna lists most of its Automower models at up to 50 percent slope, and its 435X AWD at up to 70 percent (35 degrees).
The Husqvarna page is not consistent on this point. One section gives 70 percent for the mower generally, while the slope section gives 50 percent for most models. Read the specification sheet for the exact model you plan to buy, not the general page.
- Two limits. Sunseeker advises checking the maximum incline separately for open areas and for the perimeter, since the two limits can differ.
- Drive type. Mammotion says all-wheel drive is worth considering for gradients over 30 percent, which is vendor advice rather than an independent test.
- Clear the slope. On 50 to 70 percent slopes, Husqvarna recommends keeping trees and stones off the slope.
Grass and height matter too. Our reading is that a low cutting height suits fine turf, while a rough or uneven lawn needs a higher setting. Look for the cutting height range on the spec sheet, because the verified sources do not publish a range that applies across brands.
Where will the charging station go?
The outlet is easy to miss on the list of questions to ask before buying a robot mower. The charging base needs an outdoor plug socket close enough for the cable to reach, according to Which?, which advises checking the reach before you buy.
- Measure the cable path. Check the distance from the outlet to the spot where the base will sit on the lawn edge.
- Find a clear spot. Our reading is that the base needs open ground in front so the mower can dock cleanly; check the manual for the exact clearance.
- Plan winter storage. Husqvarna says to store the charging station indoors over winter.
No source we read gives the footprint of the charging station, so measure the space before you buy and compare it with the dimensions in the manufacturer’s manual.
Do you need Wi-Fi and a phone app?
Apps are one of the questions to ask before buying a robot mower that buyers often skip. Most robot mowers are run from a phone app, which handles scheduling, location and coverage results. Husqvarna says its app connects by Bluetooth, Wi-Fi or cellular, but some features need an accessory, such as the Automower Connect kit.
Which? describes the trade-off clearly. Mowers without an app tend to be cheaper and simpler to maintain, but you must go into the garden to set the schedule on the onboard panel. Confirm which features come with the base model and which cost extra.
What will it cost to own over time?
Cost belongs on the list of questions to ask before buying a robot mower, alongside the price tag. Which? reported in 2020 that most robot mowers cost at least GBP 500 and that some cost more than GBP 1,000. Plan for the total cost over five to seven years, not just the price on the day you buy, as Sunseeker advises.
| Cost item | What the sources say |
|---|---|
| Purchase price | Most at least GBP 500, some over GBP 1,000 (Which?, 2020, UK prices) |
| Installation | Wire kit GBP 70 to 100 extra (Which?, 2020); some makers charge for installation (Husqvarna) |
| Battery replacement | Can cost more than GBP 100 in some cases (Which?, 2020) |
| Lifespan | Mammotion says a high-quality mower typically lasts 6 to 10 years (vendor claim) |
| Warranty | Mammotion lists a 3-year warranty on its wireless models (vendor claim); the Husqvarna and Sunseeker pages we read give no warranty terms |
Check the battery and warranty terms in writing before you buy. Which? does not award its Best Buy to mowers with non-replaceable batteries, so a replaceable pack is a useful test. Note that these are UK figures from 2020 and vendor claims, so read our guide to how much a robot lawn mower costs and confirm current US prices with the seller as of the day you buy.
Is it safe around kids and pets, and will it resist theft?
Safety is part of the questions to ask before buying a robot mower. A robot mower stops its blade when it is lifted or turned over, and Husqvarna recommends switching it off when small children or pets are on the lawn. That sensor helps, but it does not replace supervision, as our page on robot mower safety around kids and pets explains.
Theft protection is built into most models. Husqvarna says its Automower cannot be used without a personal PIN, and the PIN cannot be changed in the app. Its alarm and installation lock add protection, and X-line models add geofence tracking. Which? says an alarm sounds if the mower is moved past the perimeter wire, and almost all mowers have PIN codes.
- Noise. Husqvarna gives about 60 dB for its mower, against 95 to 100 dB(A) for petrol and ride-on mowers, according to the same page.
- Keep a record. Store the PIN with the warranty papers, since Husqvarna says the mower cannot be used without it.
Frequently asked questions
Is a robot mower worth it for a small yard?
It can be, but the price and installation often outweigh the time saved on a small lawn. Which? reported in 2020 that most models cost at least GBP 500, so compare that with your own mowing time and check the total cost over five to seven years.
Can I install a robot mower myself?
Many wire-based models can be installed by an owner. Husqvarna estimates 2 to 5 hours for the boundary wire, depending on lawn size and complexity, and installation is not included in its recommended retail price.
What is the most important of the questions to ask before buying a robot mower?
Check the slope rating for your steepest area, the lawn area the model is rated for, and whether it needs a boundary wire. Those three points decide whether the mower fits your yard at all.
Do robot mowers work in the rain?
Husqvarna says its Automower “mows in rain or shine,” which is a vendor claim. Check the water-resistance rating and the manufacturer’s weather guidance before relying on it in wet conditions.
Sources
- Husqvarna Automower FAQ (manufacturer): lawn size, slope, wire installation time, PIN and safety notes.
- Five questions you should ask before buying a robot lawn mower (Which?, 2020): UK prices, kit cost, outlet and battery advice.
- What to consider when buying a robot mower (Sunseeker): lawn size buffer, slope limits and total cost horizon.
- Things to consider before buying a robot lawn mower (Mammotion): AWD slope advice, lifespan and warranty claims.
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