Long enough on short grass, and about half that on the first cut of the season. A runtime is not a property of a mower; it is pack energy divided by the load, and the load is your lawn on the day.
What decides it
Pack energy, which is capacity times voltage — watt-hours, not amp-hours. Amp-hours alone cannot be compared between platforms, and listings compare them constantly.
Grass length. The single largest variable. A blade cutting five millimetres off a maintained lawn and a blade taking a third off a meadow are doing different amounts of work, and the difference is not marginal.
Moisture. Wet clippings are heavier, they stick to the deck, and the airflow has to move them anyway.
Cutting height. A lower setting takes more material per pass and loads the motor more.
Blade condition. A dull blade tears rather than cuts, which takes more energy for a worse result.
Slope, and on self-propelled machines the drive, which draws from the same pack.
What a published figure is
A bench result obtained by the manufacturer under its own conditions, which it is rarely obliged to state. It is not a declared characteristic under any standard, and it has no uncertainty attached.
Very often it is not published at all, and what appears instead is the stated area — which, on a cordless machine, is the same calculation wearing different units.
How to read the shelf instead
Look at the pack: its capacity and the platform voltage, multiplied. Look at whether a pack is included at all — the cheapest listing in a cordless family is frequently a bare tool, and that convention has its own page here. Look at the charge time, which decides whether a second session is the same afternoon or the next day.
And be sceptical of a machine whose deck width is large and whose pack is small. That combination has to be paid for somewhere, and it is paid for in runtime.
How this site handles it
Cordless pages here print capacity and voltage together, state whether the listing includes a pack and a charger, print the charge time where the maker gives one, and report any runtime as a manufacturer figure with the phrase attached. No runtime here is presented as measured, because none of them is.
Wherever this page and the maker’s own documentation disagree, the documentation wins. Every cutting width, cutting height, stated area, pack capacity, flow rate, head, sound level and application rate on this page comes from the maker’s own published figures, with the unit as printed and the source named. None of it is measured here, and no figure is converted into another convention, because a converted number is a different number. And the division this page refuses to hide: a runtime is pack energy divided by a load, and the load is your grass. A published figure is a bench result obtained on short, dry grass at a middle setting, with no uncertainty attached and no obligation to state its conditions. This page prints capacity and platform voltage together, and reports any runtime as the manufacturer’s.
The questions that keep coming in
Why is the published runtime so optimistic?
Because it is a bench figure obtained on the easiest conditions a maker can reasonably claim: short, dry grass at a middle height, on the flat, with a sharp blade. Every departure from that costs energy, and a first cut of the season departs from all of it at once.
Is a second battery better than a bigger one?
Usually, on a mower. A second pack lets you finish now; a bigger pack is heavier on a machine you are pushing and still has to be charged. On hand-held machines the calculation goes the other way, because the weight is in your hands either way.
Last reviewed 26 September 2026