LawnMaster CLMF4821A Cordless Lawn Mower 21in - Brushless Power

Our review of the LawnMaster CLMF4821A finds it best suited to homeowners with small to medium yards who want the convenience of cordless mowing without gas upkeep. The single biggest reason to consider this mower is its combination of brushless power and a four-battery kit that delivers up to about 48 minutes of runtime in typical light-to-moderate use, making it a practical choice for yards up to roughly 1/2 acre. Assembly is quick and tool-free, the controls are straightforward, and the 3-in-1 cutting options mean it handles mulching, bagging, or side discharge with no extra parts to buy.

Key Features

• Brushless motor: Provides up to 3400 RPM for consistent cutting performance over thick grass without gas or oil maintenance.
• Four-battery kit: Includes four 24V MAX 4.0Ah batteries and a dual charger so you can swap and charge to maintain extended runtime during a mowing session.
• iPower Technology display: Shows cutting mode and battery level so the mower manages power automatically and helps prolong battery life.
• 3-in-1 function: Offers bagging, side discharge, or mulching options so users can choose the best finish for their lawn and season.
• Adjustable cutting heights: Six positions from 1.4in to 3.4in let you quickly adapt the deck height for turf health or seasonal needs.
• Compact storage: Folding push handles and an upright storage profile reduce footprint for small garages or sheds.

Who It's For

The CLMF4821A is well suited to owners of small to medium yards up to about 1/2 acre who value cordless convenience and a quieter, low-maintenance alternative to gas mowers. If you need simple operation, quick assembly, and the flexibility to bag, mulch, or side-discharge clippings, this mower covers those bases while remaining relatively lightweight for carrying and transport.

Buyers with very large properties, long continuous run requirements, or those who expect heavy commercial use should look elsewhere for longer single-battery runtime or higher-capacity power systems. Also, if absolute maximum runtime per single battery is critical, note that customer reports on battery life are mixed and actual runtime varies with grass conditions.

Pros & Cons

Pros

• Powerful brushless motor that cuts thick grass effectively without gas or oil.
• Includes four batteries and a dual charger for extended mowing sessions and quick turnaround.
• Three cutting modes and six height positions deliver flexible lawn finishing options.
• Lightweight design and folding handles for easy assembly, transport, and storage.

Cons

• Battery life reports are mixed, so runtime can vary significantly with real-world conditions.
• Designed for up to 1/2 acre; not ideal for larger properties or continuous commercial use.

Specifications

Our Verdict

The LawnMaster CLMF4821A is a practical, value-minded cordless mower for homeowners with yards up to roughly 1/2 acre who want brushless performance without gas maintenance. Its four-battery kit and 3-in-1 deck give flexibility for most residential needs, and the compact foldable design saves storage space. If your priority is quiet, easy-to-maintain mowing and versatile cut options, it represents a sensible choice; those needing longer continuous runtime should consider higher-capacity systems.

Frequently Asked Questions

How long will the batteries run?
Runtime is stated as up to about 48 minutes with the included batteries, but actual time varies with grass length, terrain, and cut settings.

Can it bag, mulch, and side-discharge?
Yes, the mower supports 3-in-1 function: bagging into a 15-gallon bag, mulching, or side discharge.

Is assembly difficult?
Assembly is simple and tool-free for most users; many owners report it takes only a few minutes to set up.