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Cordless vs petrol lawn mower for a large garden

Updated: October 2026

The petrol mower starts on the third pull, and a cordless listing now promises a large lawn with no fuel. You want to know whether a battery kit can replace it. UK guides do not share one square-metre line for that decision. This cordless vs petrol lawn mower large garden page is a stop-rule for the five push rotaries in our [cordless lawn mower for large gardens comparison](/hub/lawn-and-garden-equipment/cordless-lawn-mower-for-large-gardens), not a second product table. We did not mow with them, and we did not measure fuel use. A qualifying purchase through our links can earn a commission at no extra cost to you.

The petrol mower starts on the third pull, and a cordless listing now promises a large lawn with no fuel. You want to know whether a battery kit can replace it.

Our top picks

Greenworks Greenworks G40LM41K2X

Best overall

Greenworks Greenworks G40LM41K2X
8.4/10about £269.16
View offer
LawnMaster LawnMaster CLMF4841E-01

Rank 2

LawnMaster LawnMaster CLMF4841E-01
9.4/10about £299.00
View offer
Einhell Einhell GE-CM 43 Li M

Best value

Einhell Einhell GE-CM 43 Li M
8.3/10about £239.94
View offer
On this page
  1. 1.Where the UK guides draw the line
  2. 2.What these listings actually claim
  3. 3.When a battery kit is enough
  4. 4.When petrol or a ride-on still wins

Where the UK guides draw the line

B&Q's table is the stricter public split. Medium to large is about 400–550 m², with cordless or petrol and a cut of about 37–46 cm. Over 550 m² it lists petrol and a deck over 46 cm. Over about 1,000 m² it lists a ride-on. Up to 600 m² on a product title is still a claim. Other UK writing is looser, and treats cordless as a default toward about 600 m², with petrol for a very large or wet lawn. Which? reported about 22 minutes on average across other cordless mowers, from about 10 minutes to over 40. You cannot merge the 550 m² petrol line and the 600 m² cordless line into one fact. Neither was measured on these ASINs.

What these listings actually claim

Einhell's GE-CM 43 Li M, at about £239.94, recommends lawns up to 600 m² on a 43 cm deck with two 4.0 Ah packs and a 60-minute cell. That sits above B&Q's 550 m² petrol row. It is the maker's recommendation, not a finish of 600 m² of long wet grass. The 41 cm Greenworks, at about £269.16, says up to 500 m² and medium-sized in the same bullet, and that each 2.0 Ah battery cuts 250 m². One reviewer got about 500 m² only if the grass was not left long. The 35 cm Greenworks says up to 400 m² on a deck narrower than B&Q's 37 cm start. Both LawnMaster highlights say large lawns and print no square metres, at about £299.00 for four 4.0 Ah packs and about £313.33 for two batteries whose amp-hours are not stated. Width and packs are on the buying guide.
Greenworks Greenworks G40LM41K2X

Testsieger

Greenworks Greenworks G40LM41K2X
8.4/10about £269.16
View offer

When a battery kit is enough

A battery kit in this set is enough when you mow often enough that the grass stays short, the ground is not a bog, and the packs in the box match the afternoon. Two or four 4.0 Ah packs are a different prospect from two 2.0 Ah packs. Reviewers of the 41 cm Greenworks say the small packs run out and that thick grass needs a high cut and two passes. Einhell reviewers praise the lack of petrol, and they also say it is not a drive mower. The RHS says take the pack off and store it dry and frost-free. You stop buying petrol for the cuts the battery finishes. We will not print a pence-per-mow figure. These listings do not print a sound-power number, and a battery mower is not exempt from statutory nuisance in England. If the grass is wet, do not mow. The how to mow page has the one-third rule and the high first cut.

When petrol or a ride-on still wins

Keep petrol when the grass is regularly long or wet, or when the lawn sits over 550 m² and wants a deck wider than 46 cm. A 43 cm push deck is the widest battery mower here. Around 1,000 m², B&Q's table moves to a ride-on. One LawnMaster reviewer on a garden of about that size got about two-thirds done before charging. None of these five is self-propelled. If driven wheels were why the petrol mower stayed, read self-propelled or push before you buy a bigger battery. Einhell reviews include two-pin chargers. The four-pack LawnMaster is the wrong answer once your guide has moved you to petrol or a ride-on.

Common questions

Can a cordless mower in this set replace a petrol mower?
Yes, if you mow often, the grass stays short, and the packs in the box match a flat lawn you can push. No, if you relied on petrol for long wet grass, a slope, or a lawn B&Q already places in the petrol row above about 550 m² with a wider deck. The 600 m² Einhell line does not override that.
What do I do with a lawn over 550 m²?
B&Q lists petrol and a cut over 46 cm. A looser guide still allows cordless toward about 600 m². A 43 cm push deck is the widest in this set, so a lawn well over 550 m² sits at the edge of B&Q's table.
What about 1,000 m²?
B&Q points that size at a ride-on, not at a 41 cm push deck. One LawnMaster review on a garden of about 1,000 m² got about two-thirds done before charging. Treat that as one garden, not a plan.
Will up to 600 m² survive long wet grass?
Do not count on it. The figure is the listing's recommendation, not a timed cut of these mowers. Reviews here describe a stall and a second pass when the grass is thick or left wet after a wet April week.
Is cordless quieter than petrol, and does that change the nuisance rules?
Reviewers often call the Einhell quieter than the petrol mower it replaced. These listings print no decibel figure. A quieter impression does not take a battery mower outside England's statutory nuisance test, and it is not a measured decibel either.
What running costs should I not invent?
Do not invent a pence-per-square-metre sum. Petrol costs fuel and a service. Cordless costs electricity and later replacement packs. The saving you can state is only the petrol you stop buying when a full pack finishes that week's cut on the lawn.
When should I keep the petrol mower as a backup?
Keep the petrol mower for the first spring cut, a wet fortnight, or any week the packs will not finish the lawn. Once each weekly cut stays inside one charge cycle, the can can go and the packs stay indoors.

Related pages

Best pick in this set

Cordless lawn mower for large gardens

Cordless lawn mower for a large garden: what to check

How to mow a large lawn in the UK with a battery mower

Self-propelled or push lawn mower for a large garden

Sources

Size bands are the B&Q lawnmower buying guide. Runtime spread is Which? on other cordless mowers. Noise limits are SI 2001/1701 Schedule 3. Supply duties are the Supply of Machinery (Safety) Regulations 2008. Neighbour noise is the GOV.UK nuisance guide. Mowing and battery storage follow the RHS. Lithium-ion disposal follows the NFCC. Prices, stars and kit lines are the amazon.co.uk listings captured on 22 October 2026. They are not a lab test.

  1. RHS Lawn Mowing Guide (retrieved 22 October 2026)
  2. RHS How to Mow a Lawn (retrieved 22 October 2026)
  3. Noise Emission in the Environment by Equipment for use Outdoors Regulations 2001, Schedule 3 (retrieved 22 October 2026)
  4. Supply of Machinery (Safety) Regulations 2008, GOV.UK (retrieved 22 October 2026)
  5. GOV.UK noise nuisances: how councils deal with complaints (retrieved 22 October 2026)
  6. NFCC lithium-ion batteries (retrieved 22 October 2026)
  7. B&Q lawnmower buying guide (retrieved 22 October 2026)
  8. Which? best cordless lawn mowers (retrieved 22 October 2026)