Mains-electric models are less powerful than either petrol or battery units, as they’re limited by the amount of current they can draw from a wall socket. This means they give a more ragged cut than other mowers, and struggle when the going gets tough. However, for small patches of turf within reach of an extension cord, their low cost makes them worth considering.
Mains-electric mowers are generally cut or catch only (“cut” means mowing without a catcher or mulching plug, so thick clumps of grass are returned to the lawn surface). However, some mains models, such as the Flymo Turbo Lite hover mowers, cut quite finely on the first pass and recirculate some of the clippings through the blades, offering a pseudo-mulching effect.
Ease of use
Corded mowers are the lightest of the lot. They’re also quiet and easy to start. However, dragging a power cord can be a hassle. Always use an RCD (residual-current device) plug to avoid a shock if you cut the cord.
Corded mowers are the cheapest type aside from hand mowers; you can land a decent model for $300 as they’re simple beasts with no expensive battery, charger or engine.
Cutting height range
Generally, mains-electric mowers don’t cut as low as petrol models, though Flymo hover mowers go down to 10mm (but they won’t give you as fine or even a cut at this height as a petrol mower).
Mains-electric mowers theoretically have no run-time limit. That said, you’re limited by the extension cord and they’re not designed for big jobs, so can overheat if used for long periods.
With no batteries and very few moving parts, it’s unsurprising mains-electric mowers are the most reliable type.