Cordless Grass Trimmer with Metal Blades (allOne 21V) – 3-in-1 stringless strimmer with 2 x 4.0Ah batteries
Product description
The essentials
If you want to tidy up borders, edges and stubborn weeds without dealing with extension leads, a cordless grass trimmer like this allOne 21V model is built around that exact idea. On paper it’s a “3-in-1” cordless strimmer/brush cutter approach: different blade types for different jobs, plus a telescopic pole and a 90° flipping head so you can get into awkward angles more easily.
It’s also positioned as lightweight and simple to operate. That matters if you’re doing regular small-to-medium garden jobs (paths, lawn edging, light clearing), rather than treating every session like a full on landscaping project. Still, you’ll want to read the blade guidance carefully, because it’s not designed for everything thick.
Key features that affect real-world use
The standout here is the combination of metal blades, a pure copper motor rated up to 8500 rpm, and a cordless power system with two 4.0Ah 21V lithium-ion batteries.
From a usability point of view, the adjustable telescopic pole (90cm to 120cm) and a 90° flipping machine head are meant to reduce awkward postures. You can switch between straight-line trimming and more controlled edging or weeding positions without constantly re-gripping the tool.
There’s also a safety approach you’ll notice day-to-day: it uses a double safety button design that requires pressing the lock and trigger simultaneously to start. For cordless garden tools, that’s the kind of “small” detail that can genuinely prevent annoying accidental activations.
What to expect from the 3-blade system (and where it can fall short)
This tool comes with 3 blades, each intended for different growth types:
- A plastic blade for softer grass
- A straight metal blade for lawns, weeds and small branches
- A round manganese steel blade for thicker bushes and branches (with a stated limit)
The limit mentioned is important: the manganese steel blade is described for thick bushes and branches up to 2 inches. If your “thick” is beyond that, this is where the cordless approach can get frustrating. You may find you’re better off switching to a more robust cutting method rather than forcing the tool.
It’s also worth noting the guidance about plastic blades: plastic blades are best avoided for mowing thick shrubbery branches, as they may not be suited to heavy-duty use. In other words, this kit gives you flexibility, but it expects you to match the blade to the job.
Runtime, charging, and whether it fits your garden
The kit includes 2 x 4.0Ah batteries, and the brand states a runtime of up to 45–60 minutes depending on the speed setting. Faster speeds use more power, so the “best-case” runtime probably won’t be what you get every time—especially if you’re actively cutting thicker weeds.
Charging is described as fairly quick: the batteries fully charge in about 2–3 hours. For many UK gardens, that’s practical for a weekend tidy-up. But if you’re expecting long continuous sessions, it’s still worth planning around the stated runtime and how hard the blades are working.
A small practical example: if you’re trimming the edge of a lawn and clearing weeds along a fence line, you’ll likely spend time adjusting speed and blade choice. In that scenario, the battery life will feel more “variable” than a straight mowing job, so keeping an eye on power level makes sense.
Who it’s for (and who should probably look elsewhere)
It’s a solid fit if you want a cordless 3-in-1 strimmer that’s lightweight, works around a telescopic setup, and lets you tackle typical weed removal, lawn edging and light branch trimming in one tool.
It may not suit you if you regularly need to cut heavy, thick growth beyond the stated branch size limit, or if you’re after a single-blade solution without the small “which blade for what?” routine. And if your garden is mostly dense shrub or frequent heavy-duty clearing, you might find this stays more in the middle range than a dedicated brush cutter.
What you should check before buying
Before you decide, it’s worth double-checking:
- That you’re comfortable switching between blades based on growth type
- The stated branch size limit for thicker bushes/branches
- Your typical cutting conditions and whether you’ll mostly be trimming lawns/weeds versus thicker shrubbery
- How long your usual session takes, given the stated runtime varies by speed
- Whether the 90cm–120cm pole range suits your height and working position
If you keep those points in mind, the tool’s cordless convenience and safety start system become much easier to justify.
Mini FAQ
Is it really cordless, or does it need a cable?
It’s described as a cordless strimmer powered by included lithium-ion batteries, so there’s no need for a mains cable while trimming.
What blades are included, and can I use them on thick bushes?
The kit includes plastic for soft grass, a straight metal blade for lawns/weeds/small branches, and a round manganese steel blade for thicker bushes and branches, but it’s specified for branches up to 2 inches.
How long does the battery last?
The stated runtime is up to 45–60 minutes, and it varies depending on the speed setting.
How long does it take to charge the batteries?
The charger is described as fully charging the batteries in about 2–3 hours.
Is it safe to use around gardens and paths?
It uses a double safety button design that requires pressing the lock and trigger together to start, which helps reduce accidental activations.
Is it worth it?
This allOne cordless grass trimmer looks worth considering if your garden needs frequent edging, weed clearing and occasional light branch trimming, and you want cordless freedom with a lightweight build and adjustable pole. The 3-blade setup is the key value driver, but it only works as well as your willingness to match the blade to the job and stay within the stated thickness limit.
It’s not the best match if you’re constantly cutting very thick growth or you dislike blade switching. In those cases, it may feel like you’re pushing a cordless strimmer beyond its comfort zone.