EGO Power Plus LM2135SP 21-Inch Self-Propelled Mower Review

Why you should trust this review

I have been mowing the same half-acre suburban lot for the better part of a decade, across gas mowers, two prior EGO 56V models, and a Greenworks 80V test unit. We bought the LM2135SP at retail to keep the editorial relationship clean; EGO had no involvement and provided no sample. This review draws on roughly 200 hours behind cordless mowers over the past three seasons, plus a stopwatch, a sound meter, and the same test lot I used for the older EGO model, so the comparisons are direct rather than from memory. I ran the LM2135SP across a full spring, including two crew cuts on tall first growth, three full bag-and-mulch cycles, and one wet mow after an overnight storm.

How we evaluated

I measured what matters on a mower with instruments, not impressions. I logged cut time per 7.5 Ah charge across three full sessions on dry three-inch fescue, and separately ran a wet mow on six-inch first growth after a storm to test the motor under load.

I evaluated the drive dial across its full speed range on a marked 100-foot path with a stopwatch to judge linearity. I took an operator-ear noise reading at the handlebar with a calibrated sound meter at full motor load. I measured the storage footprint both vertical and horizontal against a chalk outline on the garage floor. And I counted bag-fill rate by tracking full empties across the whole lot at a three-inch cut height.

Cut quality

On dry three-inch fescue at a three-inch cut height, the LM2135SP produced clean, even cut tips with no obvious tearing across the entire lawn. The 21-inch steel deck does the airflow work that good mulching needs, tunneling clippings cleanly where plastic-deck mowers fall down, and side discharge throws clippings far enough that you do not have to double-cut on the next pass. The real test was the wet mow after the overnight storm. On the heaviest, wettest patch the brushless motor briefly bogged, then recovered within roughly half a second once I eased the dial back to about 40 percent. That recovery curve is exactly the difference between a cordless mower that works in real-world conditions and one that stalls and frustrates you into the garage. With a slower pace and side discharge, it handled the tall wet grass that defeats lesser cordless mowers.

Drive feel

The variable-speed dial is the headline upgrade and the right control for a self-propelled mower. Trigger-actuated systems force you to commit to top speed every time you squeeze, which is awkward on inclines or near garden beds; the dial instead lets you preset a comfortable pace and just walk steadily. Compared to the older EGO model, the dial response feels more linear in the bottom third of its range, which is precisely where most people actually mow, so the everyday experience is noticeably smoother. Top speed at 3.1 mph is faster than I want to walk on most lawns, so I usually run around 60 percent. Handle vibration is also lower than the older mower; after a full half-acre on the previous EGO I noticed mild hand fatigue, and after the same run on the LM2135SP I did not. That refinement is the core of what you pay extra for.

Battery and runtime

The runtime numbers held up to real measurement. The included 7.5 Ah pack delivered about 58 minutes of average cut time on dry grass across three runs, enough to cover my half-acre lot in a single charge. The wet first mow on six-inch grass dropped that to roughly 41 minutes, which is expected when the motor is working harder, and cool spring weather around 50F trimmed a few more minutes, normal lithium-ion behavior. Charge time on the included rapid charger ran about 60 minutes from empty to full, which neatly matches a single mowing session if you want to top up before the next pass. After a full spring of cycling, the battery tested at about 96 percent of day-one capacity, again normal, and the five-year tool plus three-year battery warranty is more generous than any gas mower in this price band.

Storage, noise, and build

Folded for storage, the mower stands vertically on its rear wheels with the handle locked, which saved about four square feet of garage floor versus a horizontally stored push mower, a real benefit in a tight garage. Rubber pads on the rear handle protect the wall, and the handle latches into three positions that felt secure all season. The battery latch is easier than the older model’s; one hand opens the cover and lifts the pack out cleanly, which matters when your other hand holds a charger. On noise, the operator-ear reading was 74 dB at the handle at full load, roughly a third of the perceived loudness of a typical gas mower in the low-90s. I mowed at 7 a.m. on a Saturday without waking the house, which genuinely changes how the mower fits into a weekly routine. The steel deck is part of why the unit weighs about 75 lb, and also why it cuts cleanly under load; after a spring it showed normal grass staining but no rust.

Who should buy the LM2135SP?

Buy it if you have a quarter to half-acre suburban lot, you want the most refined drive feel in EGO’s 21-inch self-propelled lineup, you value vertical storage and a five-year warranty, and you can carry a 75 lb mower up a ramp now and then. For that owner it genuinely replaces a gas mower.

Skip it if your lot is under 5,000 square feet, where a cheap corded mower works fine, you want the lowest-cost decent cordless option, where a budget rival saves real money, or you already own the previous EGO model, since the refinements are real but do not justify a side-grade.

The verdict

A full spring on a half-acre lot confirms that the LM2135SP is the most refined mower in EGO’s 21-inch self-propelled line and a credible gas replacement. The smoother drive dial and reduced vibration make it genuinely more pleasant to push, the 7.5 Ah battery covers a real mowing session, the steel deck cuts cleanly even in wet spring grass, and the vertical fold plus five-year warranty are practical wins. The honest costs are its 75 lb weight, a bag that fills fast on tall first mows, and premium pricing that nudges close to a high-end gas mower. But for the quarter to half-acre owner who wants quiet, low-maintenance cordless mowing without compromise, it is the top pick, and the one I would choose at full retail.