Two-model comparison
Greenworks LM1934 or LM2104? Compare two 40V push mower kits
Greenworks LM1934 and LM2104 are both 40V, operator-pushed walk-behind mower kits with one included 5.0 Ah battery and charger. The short choice is not simply 19 inches versus 21: the LM2104 also has an explicitly listed collection bag and 3-in-1 clipping options, while the LM1934 page lists a narrower 2-in-1 mower for mulching and side discharge. Decide the clipping route and access before treating the wider deck as an improvement.
Start with gates and turns
The LM1934 cuts a 19-inch path; the LM2104 cuts 21 inches. An extra two inches can reduce the number of overlapping passes on open stretches, but it cannot compensate for a mower that will not clear a gate or turn between planting beds. Measure the complete mower at its widest point, not just the advertised cutting width. The product pages list different front-wheel sizes—7 inches for LM1934 and 8 inches for LM2104—with 10-inch rear wheels for each. Those wheel dimensions are useful identifiers, not a prediction that one mower rolls better on your ground.
If your route is narrow or winding, the smaller deck may be easier to place, but verify actual outside dimensions; the page does not state a total width for either assembled mower. If your lawn is mostly open and wide enough for both, the LM2104's extra cutting width may reduce pass count. Neither has powered drive, so the user provides all forward movement. If self-propelled travel is essential, these are both the wrong operating format.
Choose the clipping plan
LM1934 is documented as a 2-in-1 mower for mulch and side discharge. Greenworks does not list a bagging option on its exact LM1934 page. By contrast, LM2104 is listed as a 3-in-1 mower for mulching, rear bagging and side discharge, and its package page includes a grass collection bag. If gathering clippings is a hard requirement, LM2104 is the evidence-backed pick between these two. Do not substitute an accessory photograph, a bag from another Greenworks mower, or the fact that a machine can discharge rearward for proof that an exact bag fits the LM1934.
Bagging changes the work routine as well as the output: you empty the catcher and carry the collected material, and the mower manual says to clear clippings from the rear opening and deck after mowing. If you normally mulch, the LM1934 can meet that simpler routine while removing the bag as a package question. The exact fit and inclusion of any accessories should still be confirmed from the package code on the seller listing.
Do runtime ceilings fit your plan?
Both configurations include a single 5.0 Ah battery, and Greenworks' pages estimate about 150 minutes for charging. The LM1934 page gives up to 35 minutes and up to a quarter-acre; the LM2104 page gives up to 45 minutes and up to one-third acre. These manufacturer maximums are not equivalent to tested cut time or a guarantee that one charge finishes a yard. Grass density and moisture, height, mower pace, turns and rework affect results. If your lawn is near one of those claimed ceilings, the extra ten advertised minutes does not remove uncertainty. A second pack could change the day, but neither exact kit reviewed here includes two.
Greenworks also warns that an 8 Ah 40V pack will not allow the battery cover to close on either product page. Check the battery model and fit; the shared voltage label is not a substitute for confirming the pack will seat as intended. LM2104's page names the included battery a USB pack, while its manual says the mower has one active battery bay and a separate storage compartment.
Height and weight are not interchangeable facts
Both machines offer seven cutting positions. The LM1934 linked manual gives a 1¼–3¾-inch range, while its page also describes a 1⅜-inch minimum. The LM2104 manual gives 1⅜–3¾ inches, while the product specification table rounds that to 1.4–3.7 inches. Neither mower should be chosen on a precise lower-height cutoff without checking the manual supplied with the exact current configuration.
Weight is also uncertain rather than a useful tie-breaker. The LM1934 page lists 37 pounds but its linked manual says 40.3 pounds without the battery. LM2104's product page says 58 pounds and its manual says 61.46 pounds without the battery. The manufacturers do not reconcile these different figures. If lifting or transport is a hard condition, verify the actual mower weight with the seller or maker and compare it with the battery included; do not infer that the narrower body is automatically easier to lift.
A practical shortlist
Choose LM1934 when the 19-inch cut suits your access and mulching or side discharge is enough. Choose LM2104 when you want the wider 21-inch cut and an included bag for collection. Both remain push mowers, both require the operator to keep moving the machine, and both manuals warn against mowing wet grass or slopes over 15 degrees. For either one, remove the safety key and battery before maintenance, clean with a dry cloth or scraper, and do not hose down the deck. If those operating limits or a long recharge do not match your yard, compare another mower format rather than relying on a larger runtime claim.