The electric mower market features power ratings ranging from less than 1,000 watts to over 1,800 watts for corded models, while battery versions come in voltages from 18 V to 36 V and beyond. Given this variety, the choice of power depends on concrete parameters: the area to be mowed, the nature of the terrain, and the type of grass encountered.
Understanding what the concept of power really entails helps avoid an oversized purchase or, conversely, a machine that stalls on the first pass over dense grass.
Watts and volts: what the technical sheet doesn’t tell you
On a corded mower, the motor power is expressed in watts. A high number indicates the ability to maintain the blade rotation speed when resistance increases (tall grass, wet lawn). But this number alone is not enough to predict the quality of the cut.
To consider what power for an electric mower, one must also take into account the cutting width and the blade design. A moderately powered mower with a narrow cutting width can provide a cleaner result than a more powerful model with a deck that is too wide for its motor.
On the battery mower side, confusion is common. The voltage (18 V, 36 V) indicates the battery pack voltage, not directly the mechanical power transmitted to the blades. Comparing only the voltages between two models is not enough: the battery capacity in ampere-hours and the motor management electronics play a crucial role in the actual autonomy and cutting power.
Lawn area and terrain type: the real sizing criteria
The size of the garden remains the primary filter. A small lawn with fine, regularly maintained grass does not require the same motorization as a larger area where the grass grows quickly between mowings.
The terrain complicates the equation. A sloped area puts more strain on the motor, whether the mower is pushed or self-propelled. Dense or wet grass and a sloped terrain reduce the actual autonomy of a battery mower, sometimes significantly compared to the figures claimed by the manufacturer.
Often underestimated parameters
- The mowing frequency: mowing every ten days instead of weekly allows the grass to grow taller, requiring more power for a clean cut without clogging
- The presence of shaded areas where the grass grows differently, with longer and softer blades that wrap around blades that are too slow
- Obstacles (trees, flower beds, edges) that require frequent maneuvering and increase mowing time, a critical factor for battery models
Rather than relying on the surface ranges indicated on the packaging, timing a mowing session under usual conditions helps estimate whether the autonomy of a battery model matches real usage.
Corded or battery: power is not compared the same way
Comparing the power of a corded mower with that of a battery model is like comparing two quantities that do not describe the same thing. The corded mower has a continuous power supply from the grid: its power remains constant from start to finish of the mowing. The battery mower delivers power that may decrease as the charge diminishes, depending on the variable speed technology.
The claimed autonomies result from standardized testing conditions, not from a test on your lawn. The type of grass, the set cutting height, the outside temperature, and the terrain affect the outcome. A model advertised for a given area may prove insufficient if the terrain presents several of these constraints simultaneously.
Acoustic power and motor power: two distinct data
A common misunderstanding is to associate motor power with noise level. Power alone does not indicate noise. To compare noise between two models, one must distinguish between the guaranteed acoustic power level (LWA) and the measured sound pressure level near the user (LpA). These two values do not describe the same physical reality, and a more powerful mower is not necessarily noisier than a less well-insulated model.
Adapting power to your practice rather than a theoretical standard
There is a strong temptation to choose the most powerful model for safety. This logic leads to additional costs at purchase, extra weight (the more powerful motor is often heavier), and, for battery models, faster energy consumption without real benefit if the terrain does not justify it.
Conversely, undersizing the power forces one to mow more slowly, to go over the same areas again, and accelerates mechanical wear. The right sizing avoids both extra costs and premature wear.
- For a small flat garden mowed regularly, moderate power combined with an appropriate cutting width is more than sufficient
- For a hilly terrain or a lawn maintained infrequently, prioritize a motor capable of maintaining its speed under load, whether corded or high-capacity battery
- For an intermediate area with mixed zones (shade, gentle slope, edges), the compromise between power, weight, and maneuverability is as important as the displayed watts
The adjustable cutting height also plays an indirect role. Mowing high tires the motor less and preserves the lawn, which can compensate for slightly lower power than what the theoretical area would require.
The choice of power rarely boils down to a single number. It is the match between motorization, cutting width, terrain type, and maintenance frequency that determines whether the mower will operate under good conditions for several seasons.
