Greenworks LM2108S 21-inch 80V self-propelled mower kit, SKU 2550402 review

The Greenworks LM2108S is a 21-inch, 80V self-propelled mower sold in several battery kits. This review is for the specifically documented U.S. configuration SKU 2550402: one 4.0Ah battery and a charger, not the two-battery LM2108S bundle or an 8.0Ah package that also uses the LM2108S name. That distinction changes what arrives, the maker's runtime claim, recharge time and price from seller to seller. Check the SKU and battery list on the carton or retailer page before treating another LM2108S listing as the same package.

What this exact 80V kit establishes

Greenworks identifies SKU 2550402 as LM2108S and internal model MO80L416. The 21-inch mower has a steel deck, brushless motor, rear-wheel self-propel drive, LED headlight and seven cutting-height positions. Greenworks publishes a 1⅜-to-4-inch range. The exact kit page claims up to 33 minutes of runtime and up to half an acre with the included 4.0Ah battery, and quotes 40 minutes to recharge that pack with the included charger. These are manufacturer maximums, not a promise for a particular lawn or a measured cut test. Grass height, density, moisture, turning, slope and how often the self-propel drive is used can all change the work finished before charging.

The product page and the manual do not describe the extra feature in exactly the same way. Greenworks markets this mower as 4-in-1, including “Turbo Leaf Pickup.” The operator manual describes the Turbo button as a temporary increase in cutting speed, from the standard 2,800 rpm setting up to 3,200 rpm; it lists mulch, rear bag and side discharge as the clipping functions. The manual does not establish a fourth, separate clipping route or a leaf-vacuum attachment. A cautious comparison should count three documented clipping routes and treat Turbo as a useful boost control, not a different bagging system. Turbo can also use the battery faster, so it is better reserved for patches that need the extra cutting speed.

Choose a kit around a real mowing routine

Greenworks says its 80V batteries work across that line, not its 24V, 40V or 60V tools. LM2108SA1 is the same LM2108S mower but a different kit: one 4Ah and one 2Ah pack plus one 2A charger. Its exact manual assigns left-bay power and right-bay on-board storage, so batteries are not used simultaneously; the 2Ah unit is a spare. Greenworks claims up to 55 minutes, half an acre and a 120-minute recharge, without clarifying runtime pack swaps or whether charging time applies to both capacities. Treat these as claims, not tests. They differ from SKU2550402's 33-minute and 40-minute figures. Do not add the battery labels into one system-capacity estimate.

Mulching avoids collecting a bag but works best when the grass is cut regularly and the deck is not overwhelmed by long, wet clippings. Rear bagging is available when collection is preferable; the manufacturer specifies a 60-liter catcher for this model family. Side discharge can be handy where collecting is unnecessary. Greenworks' operating guidance cautions against wet grass and says to empty the catcher after use. No mode turns the mower into a debris shredder: clear sticks, stones and toys before starting, and follow the manual's warning to keep people and animals away from the blade's discharge area.

The self-propel feature can reduce the effort of moving a 21-inch machine, but it does not make steep or slippery ground safe. The manual's limit is 15 degrees; Greenworks advises mowing across a slope rather than straight up or down. The manual describes separate blade and drive controls plus a variable-speed setting, so there is no need to propel the mower whenever the blade is running. If a specific trigger, palm-control or dual-toggle handle style is essential, the reviewed documentation does not use those questionnaire labels; do not assume this is the same control feel as an EGO Touch Drive mower.

Storage, maintenance and limits

The handles fold for storage, and Greenworks advertises a large reduction in storage space when folded. Measure the folded machine, battery, charger and handle position against the actual shed or garage. The 21-inch figure is the cutting deck width, not the complete mower's widest point. Greenworks lists the product at 75 pounds, but the exact listing does not state whether that figure includes the battery. Treat transport weight as unresolved if lifting or loading into a vehicle is a deciding condition. The page lists a four-year limited warranty for both mower and battery; review the current written warranty and exact package documents rather than extrapolating coverage from another kit.

Before cleaning, adjusting or inspecting the blade, remove the battery and safety key and follow the manual. The manual allows cleaning the mower carefully while keeping water away from the battery compartment; it says not to clean the battery or charger with water. Do not infer a weather-resistance rating from the 80V platform or product artwork. The mower is a poor fit if you must mow wet grass, need a verified transport weight, require a particular bagging blade, or expect one charge to finish a difficult half-acre lawn.

Who should consider LM2108S?

Shortlist this exact 2550402 kit if a steel 21-inch deck, self-propel drive, included single 4.0Ah 80V battery and three practical clipping routes fit the job, and if its 80V battery family is useful to you. Compare the 48V LM2112S when a two-pack Greenworks 24V system is a better match for tools you own; it includes two 5.0Ah batteries, quotes up to 60 minutes and has a three-year tool/battery warranty, but its manual and main product description establish only mulch, bag and side discharge. The narrower Greenworks LM2104 is push-only and 40V, but its exact 21-inch configuration also includes a 5.0Ah pack and bag. Decide by exact kit SKU, clipping modes, storage space, battery compatibility, and the written slope and wet-grass cautions—not voltage alone.

Manufacturer evidence: Greenworks LM2108S SKU 2550402 product page and its Greenworks-authored P0805346-00 operator manual. The alternate LM2108SA1 package page links its P0807261-01 manual.