The Segway Navimow Terranox — every video, spec and install, on one page

Coverage, battery and runtime — nothing else. The CM120M1 is rated to 3 acres on a 20 Ah pack (145 minutes a charge, about 0.37 acres per charge); the CM240M1 is rated to 6 acres on 25 Ah (180 minutes, about 0.5 acres per charge). Same 17-inch deck, same 4WD, same VisionFence and NRTK navigation, same app. List price $5,499 and $6,999; confirm current commercial pricing and lead times with us.

Neither. It steers by EFLS NRTK — network RTK corrections over its cellular connection, fused with 360° vision and visual-inertial odometry — so there is no perimeter wire to trench and no reference antenna to survey in. The catch is the word 'cellular': the corrections need signal at the lawn. Where there isn't any, Segway's Signal Enhancement Antenna is supported and a local correction source does the job — that's what kept our Pine Creek mountain install precise. Our free map estimates the cellular coverage at your address before you buy.

Yes — under the conditions of the rating. Segway's own footnote says the 72-hour figure includes charging and was measured on a flat, obstacle-free lawn: 180 minutes mowing plus 180 minutes charging per half-acre cycle, four cycles a day, three days straight. It's an honest ceiling, not a planning number. Skip the overnight dew hours and one CM240M1 realistically covers about an acre a day; the calculator on this page runs it for your acreage.

In a realistic 12-hour dry window — roughly 10am to 10pm on a Mid-Atlantic summer day — the CM240M1 completes about two of its 6-hour cycles at 0.5 acres each, about 1.0 acres a day; the CM120M1 lands near 0.9. On spec-sheet 24/7 conditions it's double that, but that means mowing through dew, which we don't recommend for the turf.

Its all-wheel drive — four driven wheels with dual independent steering motors — is rated to 40°, about an 84% grade, the same figure as the residential X4 but on a heavier chassis with more suspension travel. On a Pine Creek Valley mountain property it held terrain that had been sticking two Mammotion Lubas. A slope rating still assumes traction: wet grass, thin turf and what sits at the bottom of the hill get assessed zone by zone on the site visit.

Price both. Two 120s give you two docks, two independent machines and full redundancy on the same six paper acres — often the better configuration on split sites, campuses or anywhere a road or building divides the turf, not the compromise. The principle either way: two units at roughly half load beat one unit pinned at 100% on pass time, failure tolerance and turf quality. On 2–3 acres the same question is two X450s against one Terranox, and that comparison is on this site.

Bigger than the rating math suggests. A mower rated right at your acreage has to run nearly every available hour, leaves no margin for rain days or the spring flush, and wears faster — most robot-mower problems we see start with undersizing. On our 3-acre Chester, MD install we put the 3-acre CM120M1 on a lawn that strictly needs less, so it mows the whole property daily with capacity to spare. Size for your lawn's worst week, not its average week.

No. Commercial grade describes the machine, not the customer. Five, ten or twenty acres of home turf is the same mowing problem a campus has, and the same duty cycle, 4WD and NavimowFleet software that hold a corporate campus hold a big rural property. A 20-acre homestead pencils out as a fleet of five or six units, planned the same way. Under about two acres it's overkill — a Navimow X450 or LUBA 3 does that job for far less.

Every four weeks in season, on a calendar, not when they look dull — dull blades raise motor load, which cuts area per charge, which costs you acres a day. Swap complete pre-loaded cutting discs rather than twelve individual blades: a two-minute change instead of a twenty-minute chore, so it actually happens. The disc will also take extra blades — about 33% more cutting edges — which is the first upgrade we suggest on thick, fast-growing turf.

Blue means everything is good — it has the positioning accuracy it needs. Yellow means satellite signals aren't coming through properly: positioning quality has degraded, usually from tree cover, terrain shadowing or interference. Red means it cannot operate — positioning has been lost to the point where safe, accurate mowing isn't possible. On a wide-open lawn you may never see anything but blue; on a mountain property the lights tell you about your sky view zone by zone.

It's IP66 with a rain sensor and a weather-forecast hold, so rain and dew are a non-event for the machine, and at 68 dB(A) it's quiet enough to run beside occupied buildings after dark. We still schedule around the moisture window — roughly 10am to 10pm here — because wet mowing clumps clippings, packs the deck, dulls blades faster and spreads fungal disease with the mower as the vector. The machine survives dew; the turf shouldn't have to.

Segway covers the mower and charging station for two years and the battery for one; as an authorized dealer and service center we handle claims here. The NRTK & Connect+ cellular plan that carries the RTK corrections is bundled for 1 year on the CM120M1 and 2 years on the CM240M1, then renews at $59.90 a year.