Recently, electric lawn mowers have been designed to have sufficient power to be able to mulch grass and leaves giving yardeners more choices in selecting a lawn mower.
Power - Gasoline engines still offer more power than is available from the electric versions so are still preferred by most yardeners for larger lawns over 1/4 of an acre.
Electric mowers are capable of effective mulching action. The primary attraction is that an electric mower makes much less noise than do the gas driven versions; 62 to 82 decibels vs. 89-95 dB for gas engines. Electric mowers operate with no concern about filling gas tanks, replacing spark plugs, or changing oil which attracts many yardeners.
Electric mowers now come in two versions. There is the corded version which gets its power from an extension cord plugged into a power source. The newer cordless version runs on a rechargeable battery.
The electric corded mowers do not need to have any batteries replaced, but do suffer from the need to be constantly managing the extension cord as one is mowing the lawn. These corded version are generally limited to 100 feet of 14 gauge extension cord; beyond that distance, the voltage drops off dramatically.
The cordless versions have no cord to worry about or inadvertently cut off, but after four or five years will need to have the battery replaced. While the conditions of the lawn will cause great variation in the time a battery charge lasts in one mowing, you can assume that you have from one to two hours of mowing on a single charge. The electric mowers are lighter than their gas driven cousins, so are easier to lift up stairs or into a storage area. They also take up less space in storage.
Width of Cut - Generally the electric mowers cut a more narrow swath than do their gas driven cousins. Electric mowers cut anywhere between 16 and 19 inch swaths while most gas driven mowers cut 20 to 22 inch widths. Again, if you have a large lawn, the gas driven mower with the wider cut saves a lot of time compared to the narrower electric model.
Costs - When you compare total costs - purchase and maintenance - the electric mowers are cheaper than the gas driven mowers of similar power.
Summary - In the end, if you have a small yard the electric mowers are definitely an option to consider. The larger yards still need the additional power and wider swath of the gas driven mower to keep the objective of a low maintenance lawn in sight.
The gas mowers are still better than the electric mowers in mulching lots of leaves while mowing the grass.