Black Decker tools are cheaply made

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Bosch, Makita, Einhell, 12 or 18 volts - tens of manufacturers offer a huge selection of battery-operated tools. What do you have to consider when buying? TechStage shows what matters.

Batteries no longer only operate the classic cordless screwdriver. They now also fire hammer drills, circular saws, angle grinders, miter and miter saws, as well as curiosities such as e-scooters and heated jackets. The advantages of the cordless machines are the more convenient handling, the more flexible usability and higher work safety. But can devices with a battery adequately replace the corded machines and does the use of such machines always make sense? The question of cross-brand compatibility also arises when purchasing.

Anyone who works less with a drill or jigsaw, but is enthusiastic about multimeters and soldering stations, is wrong here. In this case, the guide to The Best Tools for the Nerd Workshop is more suitable.

In order to be able to properly enter the subject of cordless tools, the terms voltage and capacity should be clarified beforehand. The batteries of electric tools work with different voltages. The voltages on the devices range from 3.6 volts over 12 to well over 18 volts. As a rule of thumb, the higher the voltage, the more power the device has available - at least when it comes to comparable devices with the same battery technology and brushless drive.

This can be illustrated well using the example of a cordless screwdriver. Mini screwdrivers for model building or handicrafts often work with just 3.6 volts. This is enough to screw smaller screws into or out of threads. The torque of such mini cordless screwdrivers is usually less than one Newton meter (Nm).

Larger one-hand screwdrivers with 3.6 volt batteries produce up to a maximum of 5 Nm. That is at least enough for assembling an Ikea cabinet. More powerful one-hand screwdrivers usually work with 7.2 volts and achieve a torque of around 4 to 8 Nm. This means that longer wood screws can also be screwed into pre-drilled holes or larger furniture can be assembled.

Hand screwdrivers from 12 volts are suitable for thicker screws or those that are to cut into soft wood. We recommend devices with a torque of at least 30 to 40 Nm for classic home cordless screwdrivers. This means that drilling in softer materials such as plasterboard or wood also works. If there is enough torque and an impact function available, drilling in stone or concrete will also work. However, caution is advised when buying. The maximum torques of such do-it-yourself cordless screwdrivers differ extremely widely from manufacturer to manufacturer and from model to model. You should definitely take a closer look here. While the € 35 cordless screwdriver BSA 12-201-24K from Güde only achieves a torque of 25 Nm, significantly higher values ​​are possible with strong branded devices. For example, according to the manufacturer Bosch, the EUR 60 DIY Easy ImpactDrive achieves 100 Nm. The Milwaukee M12 BIW12-0 model, which is available from 90 euros without a battery, achieves up to 138 Nm according to the data sheet. Much higher torque values ​​can be found at 12 volts, but these devices are then either very expensive or they are embellished values.

Anyone who regularly turns more than just a handful of small screws in wood and also wants to drill in reinforced concrete usually works with hammer drills with at least 18 volts. The torque of such devices should sensibly be beyond 80 Nm. This means that the processing of screws with a very large diameter and drilling in hard materials such as hardwood or concrete is unproblematic. The 18-V-Schlagschauber TE-CI 18 from Einhell with 180 Nm costs, without battery and charger, for example 60 to 70 euros. The Makita DTW190Z model even manages 190 Nm and is available without accessories from 70 euros.

We have compared the technical data of various cordless screwdrivers and rotary hammers with a voltage of 18 volts below. The list contains the cheapest offer from the respective manufacturer.

With one exception, it is the solo version (without battery) of the respective tool. The Black & Decker BDCDD186 drill / driver is cheaper in the set than the manufacturer's solo model.

Anyone who already has a battery and charger should buy such a solo device. When purchasing for the first time or if you want additional batteries, the sets are usually cheaper.

Higher voltages are not common in the hobby and DIY sector. Even if the 12 volts are easily sufficient for the classic cordless screwdriver, there are devices that need more power - for example hand-held circular saws. Corresponding devices are available, but in the specific example their maximum cutting depth is then too low for many applications to be useful. If you also want to use hammer drills, saws or angle grinders in the future, you will be better off with an 18 volt system - and in order not to need different battery systems, you should rely on this technology when you first buy the cordless drill.

With two 18 volt batteries connected in series, even more is possible. A clear example is the Elmoto Kick e-scooter (test report) with Einhell battery slots; The powerful DLS211ZU miter saw from Makita goes in a completely different direction - also with a double 18 volt battery.

The capacity of the battery tells you how much energy it consumes. With the same voltage, the following applies: the higher the capacity in Ah, the longer the battery will last. But it is also more expensive, heavier and takes longer to reload. For example, charging a 3 Ah battery with 18 volts from Makita takes about 25 minutes. This battery costs around 42 euros and weighs 540 grams. The larger 6 Ah battery from the same manufacturer weighs 670 grams, costs 69 euros and it takes more than twice as long to charge at 60 minutes.

And what does that mean in practice? The answer to this question depends entirely on the intended purpose and the type of work. With a cordless screwdriver, the energy required depends, for example, on the torque used. This means that thick and long screws draw significantly more power from the battery than thin and short screws. If you just want to turn a few handfuls of medium-sized wood screws into soft wood every few weeks, you will be well served with a small battery. Anyone who handles tools professionally or is a DIY enthusiast on a large scale and builds entire gazebos needs significantly more capacity. Here, for example, batteries with 4 Ah to 6 Ah come into question.

However, from our point of view, it is better to buy two or three batteries with low to medium capacity and change them regularly instead of buying a fat monster battery. On the one hand, the tool remains lighter and more manageable; on the other hand, it can be exchanged directly when the battery is empty - and finally several tools can be used in parallel without having to constantly change the battery.

From our point of view, there is another reason to include the 18 V devices in the shortlist. In principle, batteries only ever fit into devices from the same manufacturer; you cannot operate the Makita saw with the Bosch battery - unfortunately.

In the meantime, there are at least two larger associations of manufacturers who share a common battery technology with 18 V voltage and whose devices are compatible with each other. The Cordless Alliance System (CAS for short) launched by Metabo and the Power For All Alliance initiated by Bosch.

While the CAS mainly includes companies specializing in professional craft such as Metabo, Mafell, Rothenberger, Steinel or Birchmeier, the Power For All Alliance is interesting for private users. In addition to Bosch, the paint spray system manufacturer Wagner and the garden tool manufacturer Gardena, among others, are represented here. So if you are planning to convert both tools and gardening tools to battery operation, you should keep this in mind.

In order to get a rough overview of the almost endless range of cordless tools, we have selected the most popular manufacturers for use in the private sector and show what their product portfolio contains. If you want to use your batteries with different electrical devices, you should check here briefly whether the desired manufacturer even offers all the equipment you need. The manufacturers Dewalt or Milwaukee offer very interesting prices for tool sets, but when it comes to gardening tools, you look down the drain. Bosch, Einhell and Black & Decker, for example, are much more broadly positioned here. Manufacturers such as Gloria or Gardena offer cleaning and gardening equipment, but do not have any tools in their range. At this point, cross-manufacturer compatibility, as with Bosch and Gardena, is interesting.

Black & DeckerTools, lights, garden tools, measurement technology, cleaning equipment
BoschTools, paint spray systems, garden tools, measurement technology, cleaning equipment
DewaltTools, measuring technology, cleaning equipment
EinhellTools, garden tools, cleaning tools, measurement technology, e-scooters
GardenaGarden tools, cleaning tools
GloriaGarden tools, cleaning tools
GüdeTools, garden tools, cleaning equipment
MakitaTools, garden tools, measuring technology, cleaning equipment
MetaboTools, garden tools, cleaning equipment
MilwaukeeTools, garden tools, measuring technology
RyobiTools, garden tools
stalkGarden tools, cleaning tools
wagnerPaint spray systems
WorxTools, garden tools

But what tools do you actually have to invest in household and hobby tools? Is the inexpensive own brand from the hardware store and discount store enough or does it have to be a device from a well-known manufacturer? And just as important, does it have to be a battery-powered device? There is no general answer to these questions. That depends on numerous factors such as personal requirements, available budget, purpose and frequency of planned use.