BLACK+DECKER Lithium-Ion Lawn Mower with Two 2 Ah Batteries, 36 V

BLACK + DECKER is one of the top selling power tool companies in the UK, yet they also produce a range of garden power tools, including a great selection of cordless lawn mowers. These products have the trademark BLACK + DECKER quality along with a reasonable price point, making it a good choice for those seeking reliable products from a trustworthy brand.

The CLM3820L2 is a 36V cordless lawn mower that is recommended for medium and large size gardens. Equipped with a powerful battery that offers excellent runtimes and fast charging, the product includes two batteries and a charger, giving you everything you need for mowing those more sizeable lawns.

Offering exceptional cutting power, six cutting heights, and a lightweight design, this is a great investment for anyone with a larger lawn seeking a quality cordless mower. Let’s take a closer look at the CLM3820L2 to see what is offers:


  • 2 x 36V 2Ah Lithium-Ion Batteries
  • 38cm Cutting Width
  • Six Cutting Heights (30mm-80mm)
  • 35L Grass Box
  • Integrated Carry Handle

Battery and Motor

The CLM3820L2’s electric motor is powered by a 36V lithium-ion battery, providing around 30 minutes of runtime and a charging time of around 45 minutes. (compare against other models here) Normally, these specs would make it a good choice for medium lawns up to around 300m2, yet with a second battery included with the lawn mower you effectively double the runtime.

That means you can expect around 60 minutes of runtime, which is enough to mow even the largest of lawns, with enough power to mow an area roughly 600m2. Of course, conditions vary and can impact battery performance, but the CLM3820L2 boasts an impressive motor that maintains good battery performance even on poorer condition lawns.

The high torque cutting system is designed to handle tougher growth common on many UK lawns. This means the mower doesn’t struggle to cut long or even damp grass, something many electric and cordless mowers cannot do that well.

Therefore, if you tend to let your lawn grow longer before mowing it or it generally gets wet and overgrown, then the CLM3820L2 is a great option because it can handle these harsher conditions.  

Normally we recommend buying second battery to improve the mower performance, but this is one of the few products that includes two batteries alongside the mower – all for an excellent price!

As it is designed for prolonged use on larger lawns, the mower does come with a length 38cm steel cutting blade. This provides the necessary width to make mowing on larger lawns quick and easy, removing a good portion of the grass with just a single pass – anything too narrow means more passes are required.

38cm is on the higher side for a cutting width, highlighting the mower’s suitability for larger lawns. It is still suitable for medium lawns too, especially given the fact the mower is on the lighter side so relatively easy to manoeuvre for most gardens.

The width may be too wide if your lawn is narrower, although most large lawns tend to have a lot of space so this shouldn’t be an issue for most. As for the quality of the cut, the blade produces a clean and precise cut, ensuring a neat and tidy finish.

Cutting Heights

BLACK+DECKER Lithium-Ion Lawn Mower with Two 2 Ah Batteries, 36 V

The CLM3820L2 comes with a six cutting widths, the most you are likely to find on a cordless lawn mower. This makes it incredibly versatile, allowing you to cut the lawn to different heights depending on its condition that day.

For example, the highest blade position is 80mm from the ground, and this is a good height for cutting longer grass. You should never remove more than one third of the grass length at one time, so the higher settings are good for lawns that get a bit longer – another example of how well it works on long and dense lawns. 

30mm is the lowest setting for the blade, allowing to produce a clean and short cut, which is recommended during spring and summer when the grass is actively growing, so you have plenty of options when it comes to what height you want to mow the lawn to.

These are easily adjustable through the lever on the central cutting deck.


BLACK+DECKER Lithium-Ion Lawn Mower with Two 2 Ah Batteries, 36 V

A common issue with lawn mowers designed for large lawns is they can be difficult to operate. They are typically heavier and clunkier than other mowers, so some gardeners struggle to push and pull them around the garden, especially if the terrain is uneven.

Thankfully, the CLM3820L2 has no such problem, being surprisingly lightweight () for a lawn mower in this size range. This is thanks in no part to the excellent battery that reduces the weight, while the wheels and plastic deck also help keep the weight down.

Manoeuvring the mower across the lawn is easy, even when grass is longer, with the high performance motor effortlessly mowing through all growth. While the cutting deck is wider than some models, it remains easy to move thanks to the lighter weight and well-designed wheels.

There is also an integrated handle on the cutting deck for easier carrying to and from storage, while the mower handles come with some padded to reduce vibrations and maintain comfort. Given that the mower has a runtime up to 60 minutes, it is important that it remains comfortable to operate, so its nice to see that BLACK + DECKER have made this possible.  

Grass Box and Storage

BLACK+DECKER Lithium-Ion Lawn Mower with Two 2 Ah Batteries, 36 V

There is not much in the way of extra features for the mower, with a gras box included as is standard with most products. At 35L the grass box is a decent size but may need emptied when working on larger lawns with long grass, although it is quick and easy to release from the cutting deck to empty.

Storage is made easier by a foldable design, which is especially useful given that the mower is on the larger side. The handles fold down onto the deck, making it very compact and simple to store.


  • Includes two batteries where most products only offer one
  • 30 minute runtime per battery for a total of 60 minutes
  • Charging time of 45 minute per battery
  • Large cutting width for faster mowing
  • Excellent cutting performance even on overgrown lawns


  • Grass box could be larger
BLACK DECKER Lithium ion Lawn Mower Cordless 36V 38cm Includes Two Batteries 2.0Ah with 35L Grass...100
  • Cutting mechanism: rotary/metal blade. Supplied with two powerful 36V lithium batteries for gardens up to...

Last update on 2022-04-11 / Affiliate links / Images from Amazon Product Advertising API

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