How to clean a cordless lawn mower

Safety first

Always take the battery out before cleaning, and remove the safety key if your mower has one. Wear gloves, because the blade is sharp even when it looks blunt. Check the manual for which way the mower may be tipped; some makers say to tip it on its back, others on its side.

Note:Never clean a mower with the battery fitted. Keep water away from the battery compartment, the motor vents and the switch box.

Do battery mowers need oil?

No. Battery mowers have no engine, so there is no engine oil to change, no fuel and no spark plug. The motor is sealed. The only lubrication most owners need is an occasional light spray on height adjustment levers or wheel axles if the manual suggests it. That makes cleaning the main maintenance job.

Cleaning after each mow

A two minute clean after each cut stops grass building up and drying hard on the deck.

1. 1

   Remove the battery and safety key

2. 2

   Empty the grass box and knock it out

3. 3

   Tip the mower as the manual allows

4. 4

   Brush or scrape loose clippings from under the deck with a plastic scraper or stiff brush

5. 5

   Brush clippings off the top, the wheels and the motor vents

6. 6

   Store the mower and battery somewhere dry

Why you should not hose a battery mower

Most cordless mowers are not designed to be washed with a hose or pressure washer. Water can get into the motor, switch or battery contacts. Wipe the outside with a damp cloth instead, and use a brush on the deck. If the manual says the deck can be rinsed, or the mower has a washout port, follow those instructions and keep water away from the electrics. Let the mower dry fully before you refit the battery.

Why mowing wet grass makes cleaning harder →

Check the blade

While the mower is tipped, look at the blade. Nicks, a rounded edge or a bent tip all affect the cut. A blunt blade tears grass and leaves brown tips. Our guide to sharpening or replacing mower blades explains what to do. Check the blade bolt is tight, using the torque or method in the manual.

The end of season clean

Before winter, give the mower a thorough clean. Scrape the deck back to bare plastic or metal, clean the grass box mesh with a brush, check the wheels turn freely, and wipe the body. Store the battery indoors, at the charge level the maker recommends, rather than in a cold shed. Our guide to storing mower batteries over winter has the details.

Making cleaning easier

Mow when the grass is dry, because wet clippings stick to everything. Keep the cutting height sensible and follow the one-third rule, as cutting very long grass packs the deck faster. Some mowers have smoother decks or plastic undersides that shed grass more easily. If you are buying, light, compact mowers like those in our cordless mowers for small gardens are also easier to tip and clean.

Try the one-third rule tool →

Cleaning the grass box and battery

The grass box needs attention too. Fabric boxes clog with fine dust, which reduces airflow and stops the box filling properly. Turn it inside out where possible, knock it against a wall and brush the mesh. Plastic boxes can be rinsed with a hose, away from the mower, then left to dry fully. A clean box fills evenly and is easier to empty.

Look after the battery as well. Brush dust off the battery and wipe the contacts with a dry cloth. Check the battery bay on the mower for grass or dirt, as debris on the contacts can cause the mower to cut out. Never clean a battery with water or solvents. If the casing is cracked or swollen, stop using it and contact the maker.

Finally, check the height adjustment lever and the handle clamps. Grit can make them stiff. Brush them clean and, if the manual allows, use a light spray of silicone lubricant.

Frequently asked questions

Can I wash my electric lawn mower with a hose? Usually not. Most makers advise wiping and brushing instead, to keep water out of the motor and electrics.

How often should I clean a cordless mower? Brush off clippings after every mow and do a thorough clean at the end of the season.

Do battery lawn mowers need servicing? Not like petrol mowers. Keep the deck clean, the blade sharp and the battery stored well.

What is the best tool for cleaning under the deck? A plastic scraper and a stiff brush. Avoid metal tools that could damage a plastic deck.