Best Robot Lawn MowersA Justamanstanding project
Segway Navimow X390$4,999

Segway Navimow · 2.5 acres · Wire-free

Segway Navimow X390

A capable large-lawn RTK mower with a 50% slope rating, but it is rear-wheel drive and the second antenna is extra if one base station cannot cover the yard.

What it is

The Navimow X390 is the 2.5-acre model in Segway’s X3 series. It is a perimeter-wire-free robot mower that locates itself with Segway’s EFLS 3.0 stack (RTK plus visual odometry / V-SLAM) and uses a 300° RGB plus time-of-flight camera for obstacle detection.

Official US specs for the X390: 2.5-acre recommended mowing area, 50% (27°) maximum slope inside the work area and 25% (14°) at the boundary, 9.3 in cutting width, 2–4 in automatic cutting height, 12.8 Ah battery, about 100 minutes to charge and 240 minutes of mowing per full charge, 60 dB(A), IP66, and 43.9 lb.

Who it’s for

People with large lawns who want to skip burying a boundary wire and who can give the RTK antenna a reasonably open sky view — or who are in a Network RTK coverage area, where Segway says a local antenna is not required. It is a weaker match for very steep, wet hills better served by all-wheel-drive machines, and for tiny suburban lots where a cheaper vision mower is enough.

Standout details

  • Coverage: 2.5 acres recommended. Segway notes map storage up to about 1.2× the recommended area; actual mappable area depends on layout.
  • Navigation: EFLS 3.0 is described as RTK plus VSLAM and VIO. Object detection is 300° RGB+ToF. That is not spinning LiDAR.
  • Setup: Wire-free. The app can recommend charging-station and base-station placement. A second antenna is sold separately if one station cannot cover the whole property.
  • Drive and slope: Rear-wheel drive with a claimed 50% max climb and traction control. Boundary slope is a more modest 25%.
  • Connectivity: Bluetooth, Wi-Fi, and 4G. The X390 spec lists five years of included 4G. Alexa and Google Home are listed.
  • Other verified specs: 27.5 × 21.7 × 12.1 in; six blades; 3.3 ft/s max mowing speed on this model; weather-adaptive scheduling; GPS theft tracking.

Sources: Navimow X390 product page and X3 spec sheet, checked 26 Aug 2026.

Honest verdict

The X390 is one of the more complete large-lawn, wire-free RTK options with published numbers that match the marketing (2.5 acres, IP66, quiet). The caveats are mechanical and installation, not the spec sheet: rear-wheel drive on 50% grades, a boundary slope limit of 25%, and extra hardware if the yard needs two antennas. Pay the MSRP only if street pricing has disappeared; the official store was already below list when this page was written.