Segway Navimow i105N Robot Lawn Mower

An eighth-acre mower that still needs an antenna sited well

The i105N is the smallest of the Navimow i Series and the N suffix means the United States and Canada version. Navimow's own specification table gives the recommended mowing area for the i105N as one eighth of an acre, with an area capacity of 60 to 100 square metres per hour, which it converts to 0.015 to 0.025 acre per hour. Typical mowing time is about 90 minutes per full charge and charging takes about 60 minutes.

Wire-free does not mean nothing to install. The box contains a GNSS antenna, an antenna installation kit, a charging station and kit, a power supply, a 10-metre extension cable and ten pegs to secure it. The antenna is the part that decides whether the mower works: Navimow says it must sit at least 2 metres from houses, trees and walls, on flat non-hardened ground, upright and never on a slope, with the sky directly above it unobstructed.

If full openness is impossible, Navimow's instruction is to keep the southern sky clear in the Northern Hemisphere. An Antenna Extension Kit for wall or roof mounting is sold separately, and Navimow warns that whenever the antenna's location changes, the existing map cannot be used and you have to map the lawn again. It also warns that roof-mounted antennas of any sort need lightning protection.

Twelve zones, one-metre channels and two kinds of boundary

Mapping is done by guiding the mower from the app, with an Assist Mapping mode in which the camera finds clear lawn edges and the mower drives them itself. Navimow asks you to keep the phone active, not switch apps, and stay within 6 metres of the mower while Assist Mapping runs.

You can create up to 12 zones on a map, each with its own name, mowing direction and schedule, joined by channels. A channel that the mower must pass through has to be wider than 1 metre, about 3.3 feet, and Navimow also says to create a channel manually if the charging station is more than 1 metre from the lawn edge. Off-limit islands, which Navimow calls BioLife islands, have turning angles no smaller than 90 degrees.

There are two boundary types worth understanding before mapping. A standard boundary keeps the mower inside the line while it mows the edge. A ride-on boundary lets the mower ride on the edge to trim right up to a path or paving, but Navimow requires the height difference between the grass and the non-grass area to be less than 1 centimetre. There is also a VisionFence-off zone, an area where the mower switches its obstacle camera off so it will cross a stone path or a utility cover instead of avoiding it.

Cutting height is a knob on the mower, not a slider in the app

This is the detail that surprises people used to app-adjusted mowers. Navimow's instruction is to turn a knob on the top of the mower so the arrow points at the height you want, and it states plainly that the mowing height applies to all mowing zones. For the i105N the range is 2 to 3.6 inches, shown on the dial as 2, 2.4, 2.8, 3.2 and 3.6 inches.

Note that Amazon's details table lists a maximum adjustable cutting height of 2 inches and a minimum of 3.6 inches, which has the two values the wrong way round compared with the manual. The manual's figures are the ones to use, and the European version of the same machine has a different range, 2 to 6 centimetres, so do not read European reviews for this spec.

Cutting width is 18 centimetres or 7.1 inches, which matches the listing. The blade disc changes rotation direction repeatedly during mowing to even out wear. The mower weighs 10.9 kilograms, 24 pounds, measures 545 by 385 by 285 millimetres, and is rated IP66 for the body, the charging station and the power supply.

Slope figures, weather behaviour and what the camera does

Navimow's specification table lists a maximum incline at the boundary, a maximum incline inside the working area and a minimum angle for a cutting area, with the values 30 per cent, 10 per cent and 90 degrees. The table extracts as separate label and value columns, so we are not going to assert which percentage belongs to which row. Plan a sloped lawn around the lower figure and ask Navimow which limit applies where before buying for a bank.

There is no rain sensor in the usual sense. What Navimow provides is Weather Adaptive: the mower reacts to real-time weather information and either stops the current task or delays upcoming ones, and you choose its behaviour separately for rain, snow, hot weather, frost and strong wind. That is a data-driven feature, so it depends on the mower being connected.

Obstacle avoidance comes from a camera Navimow calls VisionFence. The manual's sensor list gives an HD camera with a 180-degree diagonal field of view, alongside an IMU sensor, a lift sensor and wheel encoders; the Amazon bullet says a 140-degree field of view, so the two disagree. Extra camera settings include channel obstacle avoidance and an Animal friendly mode that keeps the mower away from pets and small animals such as hedgehogs.

Anti-theft only works with the 4G module and a live service

Read this before you count on theft protection. Navimow's safety section describes a PIN code, a mower-lifted alarm and a geo-fence alarm with an adjustable radius and real-time location on the map, and then states that the anti-theft feature can only be used under a 4G network and that your 4G service must not have expired.

The 4G connection comes from Navimow Access+, an IoT module listed under accessories sold separately, fitted inside the mower with a 2.5 millimetre Allen wrench and activated from the app. The Amazon listing says the same thing in two places: locating your mower in case of theft is optional with Access+, and the 4G module for anti-theft tracking is an optional add-on.

The other safety features do not need 4G. A safety lock, engaged by holding MOW and HOME for more than three seconds, keeps the mower inoperable until the PIN is entered, and a child lock stops the buttons responding while the app still works. Navimow also recommends connecting the mower to a supply circuit protected by a residual current device with a tripping current of no more than 30 milliamps.

Blades every month or two, and a real winter routine

Navimow says to replace the blades and screws every one to two months with regular use, to replace all three blades and their screws at the same time, never to reuse screws, and never to use an electric screwdriver on the blade disc. The approved blade model is HA002E, and the screws are tightened to 1 newton metre. The box includes nine spare blades and bolts, which is roughly a season's worth at that interval.

Weekly inspection and maintenance by an adult is the stated expectation. Cleaning is a soft brush, cloth or garden hose, never a high-pressure washer, never alcohol, petrol or acetone, with particular attention to the blade fender, the wheels, the camera lens and the charging port. Navimow also notes that wet grass sticks to the blades and that Navimow advises against mowing in heavy rain or on a soaking lawn.

Winter storage is spelled out step by step: pull the mower off the station with at least 85 per cent battery, power it off, disconnect the power supply and antenna, remove the blades with gloves on, wash and dry the mower, then store it indoors somewhere cool and dry. The charging station is unscrewed and its position marked with the supplied silicone pegs, because in spring the station must go back within 5 centimetres of last year's position or the map will not fit. A stored battery should be recharged every 120 days, and Navimow states that battery damage from over-discharge is not covered by the limited warranty.

On warranty, Amazon's note says a full three-year warranty. The manual's North American limited warranty section does not print a period in the text we read, but it does set out the terms that matter: coverage starts at the later of the purchase date or the first activation, blades are treated as disposable and are not covered, and if you return a unit for service you pay the shipping and carry the risk of loss both ways. Keep proof of purchase from an authorised Navimow dealer and the serial number.