Roborock RockMow S115 Robot Lawnmower

The long-runner, for a big flat lawn.

The S115 covers 1,500 m² — call it a third of an acre — and it stays out longer than almost anything else here: 150 minutes on a charge, beaten only by the flagship Z150. On a large, reasonably level lawn that means fewer trips back to the dock and a job finished sooner.

The tidiest edges we sell

Every machine in the range can cut to within 3 cm of a wall, a kerb or the edge of a bed using Roborock's PreciEdge module. On the S115 that module is included — on every other model it is an extra you buy separately. On a big lawn with a lot of boundary, that is the difference between a finished job and an hour with the strimmer afterwards.

How it gets about

Satellite positioning with camera backup: centimetre accuracy in the open, and it switches to reading what it sees when it goes in under trees. It will work through a 70 cm gap, and stereo cameras pick out obstacles and route around them rather than bumping in.

Cutting height runs from 20 to 60 mm and adjusts electrically from the app — down for the first cut of the season, back up in July, without going out to the machine.

When the weather turns

It senses rain coming, takes itself home to the dock and waits it out. IPX6 rated, so after a wet fortnight you can hose it down rather than picking grass out of it by hand. Come winter, bring it in, give it a clean and a charge, and it is ready in March.

Where it is not the right answer

It is rear-wheel drive and rated to 45% slopes. That is plenty for a lawn with a gentle fall on it, and not enough for Monaghan drumlins. If your ground is steep, soft or properly uneven, the Z115 covers the same 1,500 m² on four-wheel drive and will climb 80%. We will say so if that is you.

The numbers

• Covers up to 1,500 m² at 125 m² an hour
• Cuts 22 cm wide, 20–60 mm high, adjusted electrically, three blades
• 6 Ah battery — about 150 minutes mowing, about 65 minutes to charge
• Full-band RTK with camera backup · rear-wheel drive · slopes to 45% · climbs 4 cm
• 3 cm edge cutting, PreciEdge module included
• Up to 15 zones · 60 dB · IPX6 with rain sensing · 13.6 kg
• Alarm and PIN lock; the 4G tracking module is sold separately

Come and see it

There is usually a machine running on the demo lawn. Bring the size of your garden and whether it is flat or hilly, and we will put you in the right one — including when that is the cheaper one.