Performance is the traditional stronghold of petrol mowers. An internal combustion engine, measured in cubic centimetres (cc), generates high torque that keeps the blade spinning at a consistent, high speed even through dense, long, or wet grass. This makes them the default choice for reclaiming overgrown areas or for professionals who need to power through challenging conditions without slowing down. Self-propelled petrol models are particularly effective on large, sloped lawns, as the engine can power both the blade and the wheels with ease.

Battery lawn mowers have made incredible strides. High-voltage systems (typically 36V to 80V) combined with high-capacity batteries (measured in Amp-hours, Ah) deliver impressive cutting performance that is more than sufficient for well-maintained domestic lawns. Premium models now feature load-sensing technology that automatically increases blade speed in thicker patches of grass. However, under sustained heavy load, a battery mower will drain its power source much faster and may struggle in conditions where a petrol mower would not hesitate.

This is where battery mowers truly excel and have won over millions of users. The user experience is fundamentally simpler. To start, you insert the battery, press a button, and engage the safety bar. There's no priming, no choke, and no yanking on a pull-cord. They are generally lighter than their petrol counterparts, making them easier to manoeuvre around obstacles and push up inclines. When you're finished, you simply remove the battery and place it on its charger. There's no fuel to store or mix.

A petrol mower requires a more involved process. You need to check the oil and fuel levels before you begin. Starting involves setting the choke and pulling a starter cord, which can be difficult for some users. They are heavier due to the engine block, which can make them more tiring to use on complex lawns, even with self-propulsion. Finally, you have the ongoing task of buying, storing, and handling flammable petrol.

The long-term ownership experience is one of the most significant differentiators. A petrol mower is a complex machine that requires regular, diligent maintenance to run reliably. This includes annual oil changes, replacing the spark plug and air filter, cleaning the carburettor, and draining or stabilising the fuel for winter storage. Failing to perform this maintenance leads to starting problems, poor performance, and costly repairs.

A battery mower, by contrast, is almost maintenance-free. Beyond keeping the underside of the deck clean and sharpening the blade (which both types require), there is no engine to service. The main long-term consideration is the battery itself, which has a finite lifespan of several hundred charge cycles (typically 5-8 years of average use). However, for the life of the battery, there are no oil changes, no spark plugs to foul, and no fuel systems to clog.

A few years ago, battery mowers carried a significant price premium. Today, the initial purchase price for a good quality mower of either type is broadly comparable. A decent domestic petrol mower and a battery mower with a battery and charger included will often fall into a similar price bracket.

The real difference is in the running costs. The cost of electricity to fully charge a typical lawn mower battery is pennies. The cost of petrol to mow the same area is pounds. Over a full season, this adds up to a substantial saving. A petrol mower also has consumable costs for oil, spark plugs, and filters. The one long-term financial consideration for battery mowers is the eventual cost of a replacement battery, which can be expensive. However, for most users, the savings on fuel and servicing over the battery's lifespan will more than offset this future cost.

There is no contest in this category. A petrol lawn mower is an extremely noisy machine, typically operating between 90 and 100 decibels (dB). This level of noise is unpleasant for the operator (hearing protection is strongly recommended) and can be a significant nuisance for neighbours, especially on a quiet weekend morning.

A battery mower operates at a much lower volume, usually around 70-80 dB, which is comparable to a conversation. The difference is immediately noticeable and makes for a far more pleasant gardening experience for everyone nearby. From an environmental standpoint, a battery mower produces zero emissions at the point of use, eliminating the release of carbon monoxide, nitrogen oxides, and other pollutants into your garden. While the electricity used for charging has its own carbon footprint, this can be offset by switching to a renewable energy tariff. Petrol engines, in contrast, are known for being inefficient and polluting.