The 5-to-7-Year Robot Mower: Blades, Batteries, Winter Storage & the Real Parts Calendar
A robot mower doesn't usually die. It fades — ragged cut first, then missed strips, then a spring morning where the battery simply isn't there anymore. Almost every early fade traces to four neglected disciplines: blades, battery, contacts, and winter. This is the protocol version, with the real prices attached.
The task stack
Weekly in season (10 minutes)
- Flip and inspect (power off, battery isolated): clear wrapped grass and debris from the blade disc — a blocked disc is a standing line in manufacturer fault tables, not a rare event.
- Blade check: run a fingernail across a blade edge only if you must; better, look at the grass. Ragged, whitening tips on the lawn are the blade report card (see the blade protocol).
- Clean the sensors: camera lenses and LiDAR windows get a soft-cloth wipe. Sap and dust film degrade positioning before they stop it.
- Contacts: glance at charging contacts on mower and dock; early oxidation wipes off, late oxidation gets replaced.
Monthly / mid-season
- Full deck clean: brush out compacted clippings from the deck and wheel treads (packed wheels change traction and slope behaviour).
- Wire walk (wired owners): inspect exposed wire runs — gates, edging lines, aeration zones — and every previous splice. Breaks found in the walk are free; breaks found by the mower cost a Saturday (see troubleshooting).
- Firmware: apply pending updates in-season rather than in a spring panic, and note any subscription/connectivity status (4G and network-RTK terms vary by brand and model year — verify yours, don't assume).
The blade protocol
The razor-disc system most robots use cuts with small pivoting blades that cost almost nothing — and dull on schedule. Ragged grass tips are the #1 owner-discovered maintenance fact in this category: the mower keeps "working" while the cut quietly turns into tearing, which stresses the lawn and invites disease.
| Item | Typical price | Replace when / interval | Neglect symptom |
|---|---|---|---|
| Razor blade set (9–30 pcs) | ~$10–35 (OEM 9-packs ~$15–35; third-party bulk far cheaper per blade) | Every 4–12 weeks in season, by growth rate and debris load; replace the set, and the screws with it where the maker specifies | Ragged, whitening grass tips; longer mowing time for the same finish [AFFILIATE LINK: robot mower razor blades] |
| Fixed blade set (rotary machines, e.g. Lymow) | $29.99 | Seasonal inspection; sharpen or replace per manual | Tearing instead of cutting; disc/drive strain |
| Blade disc / carrier | Varies by brand | When bent, cracked, or chronically wrapped — inspect at each blade change | Vibration, scalping, recurring blockage |
Fitment discipline: blade patterns are not universal. Husqvarna and Gardena share patterns across much of their ranges; other brands use their own discs, hole spacings, and screw specs. A blade that "almost fits" sits wrong on the disc and cuts wrong — or worse. Match by your model's part number, and weigh third-party bulk blades honestly: they're dramatically cheaper per blade, which makes the 4–12-week cadence painless, but check screw quality and blade thickness against the OEM spec before committing a season to them.
The battery protocol
Batteries are the largest single line in the ownership stack (~$150–350 typical replacement; tracked-machine packs run far higher, to $699) and the part most often murdered by storage rather than use.
- Storage charge is a specification, not a vibe: manufacturers publish a storage charge level for their packs. Charge to it before storage — see the winter storage protocol for the full procedure. A winter at 0% in a cold garage is the documented death pattern: packs come back in spring unable to take or hold a charge.
- Temperature lockouts are information: brand error lists include "battery temperature out of range" for a reason — packs refuse charge/discharge outside their window. A mower that won't charge on a frosty morning may be protecting itself; warm it indoors and retry before buying anything.
- Know your replaceability before you need it: some packs are user-swappable in minutes; others are dealer jobs with labour on top of the part. This belongs in the purchase decision (it's eliminator #5 in the buying guide) and in your year-3 budget either way.
- Runtime is the gauge: track delivered runtime against rated once a season (spring recommissioning is the natural moment). A pack delivering ~60% of rated is telling you its replacement year. [AFFILIATE LINK: robot mower battery pack]
Parts-replacement intervals (planning table)
| Part | Typical price | Replace when / interval | Neglect symptom |
|---|---|---|---|
| Razor blades | ~$10–35 / set | Every 4–12 weeks in season | Ragged cut; longer cycles [AFFILIATE LINK: robot mower razor blades] |
| Battery pack | ~$150–350 typical; to $699 (large tracked packs) | 3–5 years (2–3 under storage abuse); at ~60% of rated runtime | Dead short of the dock; spring no-charge [AFFILIATE LINK: robot mower battery pack] |
| Boundary wire & couplers | ~$65 (Worx-class kit); couplers a few dollars each | As breaks occur; re-make aging splices proactively | "No loop signal" [AFFILIATE LINK: boundary wire kit] |
| Charging station / dock | $100–300 (charger adapters alone can run higher on specialty brands) | 5–7 years; failure or contact wear | Docked but not charging [AFFILIATE LINK: charging station dock] |
| RTK reference station (replacement) | $199 (documented for one tracked brand) | Failure/theft item — not a wear item | Total positioning loss |
| Tracks (tracked machines) / wheels & tyres | $139 / pair (tracks) | Wear-driven; faster on abrasive ground | Slope slip, turf tearing, "trapped" errors |
The annual cost, honestly totalled
One published category breakdown totals $219–$542 per year — battery amortisation $125–150, blades $12–32, wire repairs $17–100, misc parts $50–150, dock amortisation $15–60, software $0–50 — clustering around $300–400. It is a single-source estimate and we present it as indicative, not audited. The planning conclusion survives the caveat: over 5 years the parts tail is roughly $1,095–$2,710, which is why the buying guide treats parts channel and battery replaceability as purchase specs rather than afterthoughts. Against the baselines — a lawn service at $50+ per visit, or a walk-behind's fuel, oil, and blade sharpening plus your Saturdays — the robot's stack is competitive. It is not zero, and any content telling you it is zero is selling you the mower.
Winter storage (summary — full protocol is a standalone page)
Because this site launches in autumn, the short version lives here and the full protocol lives on its own page: clean and dry the mower, charge the battery to the manufacturer's storage level, store indoors off the cold floor, protect the wire ends, bring the RTK antenna in or secure it per the manual, and recommission in spring with a runtime check. Do not skip to spring and improvise — read the complete winter storage protocol and do it while the weather still lets you.
Mower already misbehaving? Start with symptom-first troubleshooting. Shopping for its replacement? The buying guide prices the 5-year picture, not just the sticker.