Battery-powered string trimmer purchasing advice: how to choose the right product

  • What You Need to Know
  • Battery-powered string trimmers are handy, independent of the mains socket as well as the petrol tank and allow time- and power-saving mowing of small and medium-sized lawns.
  • The devices are either equipped with blades, one string or two strings, whereby each version has its advantages and disadvantages.
  • Often, the batteries can be used in all kinds of garden tools. As they are replaceable, they do not suddenly “run out of juice” even when mowing larger lawns.
  • With particularly high-quality tools, the head can be rotated 90 degrees. This makes it easier to mow lawn edges.

Compact helpers for a well-tended garden

Lawn trimmers are primarily lawn mowers for hard-to-reach areas, for example near beds and patios, along fences and next to garden sheds. However, today’s electric-powered devices can handle larger lawns without the need for cables, as the batteries are replaceable and quickly recharged. The devices are quieter and more environmentally friendly than petrol-engined lawn trimmers. Inexpensive devices are available at discounters from about 60 euros, brand-name devices cost 100 euros upwards. If you have back problems or are particularly tall, there are so-called brushcutters: these are battery-powered string trimmers that are carried by a backpack-like belt. Although these models are larger and heavier than cordless trimmers, they do not put as much strain on the arm and shoulder muscles.

Battery-powered string trimmer with blade or cutting string?

Battery-powered string trimmers have one big advantage over cordless lawnmowers: they are smaller and easier to handle, which means they can also be used for lawns with many nooks and crannies or between trees. However, since they still weigh a lot, operating them in a stooped position or with arms stretched out wide is not ideal. For this reason, most devices are supplied with a telescopic pole.

trimmer cuts grass at the edge of a stone

The batteries are charged via the charger supplied. One battery charge is sufficient for average-sized plots. So if you don’t have a spare battery at hand, it doesn’t matter – within a few hours the battery-powered string trimmer will be ready for use again anyway. In the meantime, brand-name manufacturers have built up a whole range of power-driven tools for the garden around their rechargeable batteries. So the battery fits not only the battery-powered string trimmer, but also the hedge trimmer, loppers, chainsaw and other tools. Since each tool comes with its own battery, with a little planning there is always a charged spare battery to hand. This makes gardening particularly efficient.

Whether the lawn trimmer is equipped with a rotating blade or with one or two mowing threads has advantages and disadvantages in each case. The devices differ in their design and are therefore differently suited for heavier or weaker vegetation. But when is which battery-powered string trimmer suitable? If you want to mow larger and, above all, natural areas, you should opt for a battery-powered lawn trimmer with plastic blades. These mowers are more durable and can cover larger areas. If the property is natural, but planted with trees, lined with hedges and interspersed with flower pots or flower beds, a battery-powered string trimmer with a blade is usually the best choice. However, if the natural growth is grass and herbs, a battery-powered string trimmer with two-filament technology may also be a good idea. In some models, the mowing head can be folded through 90 degrees. This makes it easier to mow edges and corners when you want to keep things neat and tidy.

Battery-powered string trimmer with blade

Battery-powered string trimmers with blades are equipped with a circular plastic blade that is mounted directly on the motor shaft. These lawn trimmers are good for heavier vegetation because the blades can withstand much more than the filaments of the other variants.

Pro Points

  • Easy to change blades
  • Precise cut
  • Uncomplicated handling
  • Suitable for heavy vegetation

Drawbacks

  • Relatively expensive to purchase
  • Risk potential with hard materials

Battery-powered string trimmer with two strings

Instead of a blade, there is a thread spool on the motor shaft from which two threads hang out on opposite sides. Once the battery-powered string trimmer is set in motion, these nylon strings are set into rapid rotation, taking on grass, most lawn weeds and even thinner branches. However, the filaments do wear out, so users will need to replace them every now and then. The nylon strands do not handle really heavy vegetation so well, but this technology promises a very smooth cut and even lawn lengths.

Pro Points

  • Runs very smoothly
  • Easy to change the strings
  • Flexible in use

Drawbacks

  • Not suitable for heavy vegetation
  • Threads need to be changed from time to time

Battery-powered string trimmers with single-thread technology

Battery-powered string trimmers with single-thread technology are basically constructed like trimmers with two threads. The only difference is that only one nylon string comes out of the spool. These models are cheaper than others, but they run less smoothly and are often not as high quality as trimmers with two filaments. However, the single thread is very easy to replace compared to the two-thread models.

Pro Points

  • Easy to transport
  • Very easy to change the thread
  • Inexpensive to buy

Drawbacks

  • Thread breaks easily
  • Comparatively unsteady running

What matters when buying a lawn trimmer

Lawn trimmers are actually designed for the corners and edges that the normal lawn mower can’t reach. However, these machines are now so powerful that they can also be used to mow the driveway, smaller lawns and plots of land. Mowing with a lawn trimmer is only very tedious on larger lawns and especially those overgrown with many different plants. If you want a very even result on clean lawns, you are better off using a conventional lawn mower.

Therefore, many prospective buyers ask themselves the question: Which areas should be treated with the cordless lawn trimmer? For pure lawns without herbs and flowers, a device with average power is sufficient; the two-thread models have proven themselves here. If you only want to trim a few edges cleanly, you can get by with an inexpensive single-thread model. Strong and very natural growth, on the other hand, can be kept in check with a lawn trimmer with a blade. The more robust plastic blades are worthwhile for anyone who knows that the design of the garden may still change.

grass mowing with the motor scythe thicket knife

Lawn trimmer with thicket blade

Therefore, many people interested in buying a battery-powered string trimmer ask themselves the question: Which areas should be treated with the battery-powered string trimmer? For pure lawns without herbs and flowers, a device with average power is sufficient; the two-thread models have proven themselves here. If you only want to trim a few edges cleanly, you can get by with an inexpensive single-thread model. Strong and very natural growth, on the other hand, can be kept in check with a lawn trimmer with a blade. The more robust plastic blades are worthwhile for anyone who knows that the design of the garden may change.

Telescopic pole or carrying strap?

Battery-powered string trimmers are designed for rather short use. Most devices do have a telescopic handle, so that the handles can be roughly adjusted to the length of the arm and the overall body size. Nevertheless, the weight of the devices, which are held free in front of the body, pulls on the shoulders and neck. If you have health problems in this area or want to mow larger areas, you should choose a battery-powered string trimmer with a carrying strap. The devices marketed as brush cutters are somewhat more expensive and are usually larger and heavier, but they are much easier to hold and move. Special features of individual devices include an automatic thread extension on devices with two-thread technology or an integrated compartment for stowing the supplied (spare) blades.

Noise level

Battery-powered string trimmers are active in the garden at an average of 75 decibels. There are differences between the individual devices depending on the power. Quiet devices are of course always an advantage, but ultimately the device must also have the power needed for the respective vegetation. Battery-powered devices generally have a lower power output than devices that are supplied by cable from the socket or work with petrol. However, the battery-powered brush cutter is perfectly adequate for trimming a few edges.

The weight

Since users carry the device freely in their hands throughout use, they should also pay attention to the weight. Unlike petrol-powered lawn trimmers, the weight is not increased by refuelling, but the specified value is the final weight. Depending on the model, the weight can range from one kilogram to six kilograms. Some models also allow the attachment of a shoulder strap, which can be purchased separately.

Battery technology and accessories

Lithium-ion batteries without memory effect are standard. There are also models with nickel-cadmium batteries on the market. Depending on the manufacturer, the battery voltage is 12, 18 or 36 volts. The running times also vary between 30 and 90 minutes, depending on the supplier. Ideally, there is a capacity display, either in the form of a clear display or in the form of small lights or an illuminated bar. But be careful: Some devices are supplied with a battery but without a charger. Ideally, the charger is included in the delivery.

Ease of use

The battery-powered string trimmers of well-known brands have several functions that can be adjusted during operation via a few clearly arranged controls. The operating instructions should be clearly laid out; easy-to-understand wording or illustrated instructions are preferable. In addition, assembly and disassembly of the unit should not be too complicated. In the event of faults or defects, nothing is more annoying than a device that is complicated to assemble (or even has a glued plastic cover).

man has lwn trimmer hanging on the side

The cost

Well-known manufacturers such as Bosch, Gardena, Muscat and Ryobi offer high-quality devices that are also reliable when it comes to batteries. Although the devices are more expensive than those of other manufacturers, service and support are good. If necessary, buyers can get spare parts quickly and easily. Repair shops specialising in the respective brand devices are also available, even nationwide. This puts the high purchase costs in a different light.

Tips on use and care

A modern battery-powered string trimmer with a lithium-ion battery has no memory. Users therefore do not have to worry about always emptying the battery completely before charging. Nevertheless, the battery needs to be treated with care: strong sunlight, extreme heat and cold as well as strong temperature fluctuations are not good for the battery. The cordless lawn trimmer should therefore be stored all year round, protected from the weather, in the cellar or attic and not outside on the patio or behind the compost heap in the garden. What applies to the battery should also be observed by users for the device itself and for the charging station or charging cable.

The battery-powered string trimmer should be cleaned thoroughly after each use. No plant residues should be left on the cutting head, as these would dry out and become “caked” after a while. This can restrict the function of the trimmer. It is therefore important to store the lawn trimmer in such a way that the cutting head, which is still damp from use, can dry in the air. Alternatively, you can try rubbing the trimmer dry with a soft cloth after each use and cleaning. Moisture interferes with the electronics in the trimmer, as many components are made of metal and will eventually corrode.

Storage in a horizontal position is ideal. If users place the lawn trimmer upright and the weight of the battery and the unit is permanently suspended between the cutting head and the handle, the telescopic pole will become deformed in the long run.

Tips for use

Always keep the battery-powered string trimmer at a sufficient distance from your body so that you do not injure yourself on the cutting head. Remove electrical cables, water hoses and the like from the garden before you start mowing. Be careful not to injure your trees. Fingers have no business near the blade or the strings. If the string has to be extended manually, switch off the device beforehand and remove the battery if necessary.