HOMEDeWalt’s 21-Inch Mower Just Dropped $150 at Ace7 min read

Why Two Batteries Instead of One

The 2x20V MAX designation refers to the way this mower generates its power. Rather than relying on a single large-format battery — the kind you’d find on some 40V or 56V platforms — it draws from two standard 20V MAX batteries wired together. This is a deliberate engineering choice with practical advantages. The 20V MAX battery series is one of the most widely distributed in DeWalt’s lineup, meaning it’s easier to find, easier to replace, and compatible with a large number of other tools. If one battery runs low mid-job, swapping in a fresh one is simple. The dual-battery setup also spreads the power draw across two cells, which can help with heat management and overall battery longevity. For homeowners who already own DeWalt drills, saws, or other 20V MAX tools, the compatibility angle makes this especially appealing — existing batteries work in the mower.

What a 21-Inch Deck Means in Practice

The cutting deck width determines how wide a strip of grass the mower clears with each pass. At 21 inches, this DeWalt sits in the most common range for residential push mowers — wide enough to handle typical suburban lawns efficiently, but not so large that it becomes difficult to maneuver around flower beds, trees, or tight corners. A 21-inch deck is generally suited for yards up to about half an acre. Beyond that, the number of passes required starts to make the job tedious, and a wider self-propelled or riding mower starts to make more sense. For most homeowners with standard lot sizes, 21 inches is the practical sweet spot. It fits through standard fence gates, it’s easy to store vertically in a garage, and it gives enough coverage per pass to finish a typical lawn in a reasonable amount of time without wearing out the operator.