When is which cordless screwdriver useful? What makes a good cordless screwdriver? What power does a cordless screwdriver need? Which screw is used to drill into which material? And what does the volt number actually say about the battery? Questions that every do-it-yourselfer is guaranteed to have asked himself at some point! This WALTER guide not only provides answers to these questions, but also many other useful tips on this exciting topic. Thanks to our more than 100 years of experience, not only beginners can benefit from this guide.
All about cordless screw drivers

Battery tool selection at WALTER

When is which cordless screwdriver most appropriate? Which screw is best for which material? And what does the voltage number actually say about the battery? Questions that every do-it-yourselfer has certainly asked themselves at least once! This WALTER-Guide not only gives answers to these questions, but also many other useful tips on this exciting subject. Thanks to our, more than 100 years of experience, it’s not only beginners that can benefit from this guide.


Cordless screwdriver vs. drill

There are many different models of cordless screwdrivers, cordless drills, cordless hammer drills and so on, but which is just the right tool for the job? If it’ only small jobs that have to be done around the house like; screwing a chair leg back on or moving a shelf then a small and handy cordless screwdriver, like the WALTER 4-volt cordless screwdriver including bits, is ideal. With its compact dimensions, it can help you get into even the narrowest corners. However, for larger jobs on a regular basis, we recommend one of our top sellers, such as the 20-volt cordless drill driver. With this you can not only screw but also drill holes into walls or other materials. It is much more powerful and capable allowing you to drill or screw consistently and persistently even into harder materials.

  • Cordless drill driver: A cordless drill driver is best used for screwing and drilling work in wood or plastic. These tools are perfect for hobby do-it-yourselfers as well as beginners. This "all-rounder" should not be missing from any household as it is capable for both light and heavy use.
  • Cordless screwdriver: The cordless screwdriver itself is only suitable for screwing and unscrewing. It is usually more compact and thus helps in particularly narrow corners of the house, as it has less power, itd is generally only really recommended for occasional use. It is ideal for when working with wood and hardened plastics.
  • Cordless impact driver: Can be used for screwing into wood, plastic and metal as well as tightening and removing nuts, which can be useful for changing car tires. Thanks to their high-performance characteristics, they are suitable for both do-it-yourselfers and professionals alike.
  • Cordless impact drill driver: With both drill and impact driving capabilities, this tool will not only allow you to tighten and undo nuts and coach screws but will also give you the ability to drill holes in a broad range of materials including concrete. Both professionals and DIY user’s will find all their needs covered with this particular piece of kit.


Product typ Application field
Cordless drill driver Screwing and drilling in wood & plastic
Cordless screwdriver Screwing in wood & plastic
Cordless impact driver Screwing into wood, plastic and metal
Tightening and removing nuts
Cordless impact drill driver Screwing into wood, plastic and metal
Drill into wood, plastic and metal and concrete

Torque activation function

The torque setting plays an important role for all models. So, what is it exactly? The slipping clutch will engage as soon as the set torque is exceeded which will, when working with timber for example, prevent the screw from penetrating too far into the surface and will also help to avoid bur damage to both the drill bit and the screws head. So in actuality, the more settings that are available, the more precisely this force can be adjusted.

Different battery types

Despite their different technical characteristics, each individual cordless drill or impact driver have one thing in common; the rechargeable battery. Without it, none of these devices would be able to function. Here we will briefly explain the differences between; nickel-metal hydride (NiMH) and lithium-ion (Li-Ion) batteries. The type of battery that is powering your tool will be either written directly on the battery itself or indicated in the technical data.

  • Lithium ion battery: Li-Ion batteries are an electrochemical voltage source based on lithium. They have a particularly high energy density and have a much longer service life than other types of batteries. As a result of the latest technologies, these batteries are particularly ideal for portable tools which, a relatively small battery with a high energy density, can operate suitably.
  • Nickel-metal hydride battery: The NiMH battery is relatively old technology that is often used in the low-voltage range up to 2.5 volt. However, its connection is very sensitive to overcharging and, in this case, a rapid drop in performance can be detected relatively quickly. They are also sensitive to heat and cold, so that working below zero and above 30°C can be problematic.

Whether it is a built-in or external battery. WALTER batteries comply with all relevant safety standards and undergo ample quality control measures before they are put on sale. Furthermore, WALTER only uses lithium-ion batteries without memory effect, so that they are particularly durable.

à You can find the right battery for your WALTER tool at the onlineshop.

What does Volt or mAh tell us about the battery?

The volt number measures the voltage in the battery and the mAh measures the storage capacity and this together gives the energy in watt hours. Batteries with a high volt number are only necessary when either a high torque or a high speed is required, for example when sawing or drilling.

Much more important than a high volt number is the efficiency of the battery. For example, a battery with less volts may have a higher efficiency than one with more, if the milli ampere hours (mAh) are higher, means more energy can be drawn from the battery.

How is a high-performance battery correctly charged?

The battery is the heart of every cordless tool, so it should be taken special care of, in order to avoid unnecessary expenses!

As a general rule, a lithium-ion battery should never be fully charged or completely discharged. A working window of 20-80% is exactly right. Why is that?

  • Why is that? If the battery is too empty or completely discharged, the current flows too quickly into the battery and could cause overheating. This can have several negative effects on the battery such as destroying the cells which can reduce the battery’s long-term capacity.
  • If the charge level of the battery is above 80%, then the current must be forced into the battery with a much higher density, so that it can overheat and cause long-term damage to the battery. Overcharging the battery permanently destroys the chemical storage ratio of the battery. For this reason, it is best to orientate the charging time, as indicated in the user’s manual operating instructions.
  • Another important detail is the timing. Batteries should only be recharged when their performance noticeably decreases.

In the case of high-quality WALTER batteries however, temperature sensors are built into the batteries, making overheating impossible.

If you do not use the battery for long periods of time then remove it from the device and store it in a dry, cool place. This will prevent the battery from discharging itself. At a room temperature of 22°C the battery discharges itself at a rate of approximately one percent per day.

Replacing carbon brushes

1. First of all: What exactly are carbon brushes and where and when are they used?

Carbon brushes are sliding contacts which are usually made of graphite or graphite enriched metal. They provide the electrical contact to the collector or the slip rings of the rotating part in a motor or generator. Carbon brushes are used in many AC devices in and around the house and the workshop. As this is a wearing part, they are worn out after a certain number of revolutions and must be replaced. They sit in a suitable holder within the housing. The carbon brushes should have a minimum thickness of 5 mm - but if they are replaced beforehand, it can prevent unnecessary damage!

For the WALTER battery units, you can also find the suitable carbon brushes in our online shop.

2. How are they replaced?

The device must be unscrewed. Then the carbon brushes (usually two) should stick out directly as a black block in the housing. The carbon brushes are equipped with a spring in their holder so that they can always be in compression. Since this spring is usually latched for safety reasons, it is recommended that you loosen it carefully with a narrow-slotted screwdriver. Once you have done this, the new carbon brushes can be inserted in the same position as the old ones were and the device closed back up again. When the new carbon brushes are inserted, you can usually hear the spring snapping, so that you can be sure that they are not stuck.

Drill chuck and span

The chuck connects the drill attachment to the device itself. It should therefor always be in a healthy condition because a worn-out chuck will no longer be able to pass on a clean rotation which would then in turn, deform the drill hole or screw.

Furthermore, the span of the chuck is very important, as it determines the maximum size of the drill bit that can be used. It is important to note that, not only the maximum span but also the minimum span specifications are relevant. This will ensure greater flexibility.

When and which fixings to use?

There are different types of screws with different threads and screw profiles.
First of all, let us look at the biggest differences between metal and wood screws:

  • Wood screws are screwed directly into the material and therefore have a pointed tip at the end of the screw.
  • Nuts and Bolts are not screwed directly into the material but instead, will follow a pre-drilled pilot hole so then the fixing bolt can then be secured with a nut.
  • Metal screws or self-tapping screws also have a pointed tip and are used in specific situation like fixing sheet metal to timber.

For this to work properly, however, the profile of the screwhead and that of the bit must match exactly so that neither the screw nor the bit is damaged and slippage is prevented. There are quite a few different screwhead profiles. Some common ones for simple screwing are Phillips, Pozidriv or external hexagon. They are sufficient for easy tightening and multiple screwing in and out. However, if the screw needs to be tensioned particularly tight then Allen® or Torx® screws are best suited. Due to the many corners and edges in the profile of the screw head, slipping or burring is prevented so the screw can be tensioned easily all the way in.

For particularly specific components, or things that should need to be unscrewed precisely then there are so-called safety profiles. These are custom-made products, for which there is often no tool in mass production. A good example for this is the disposable slotted screws. These can only be screwed in one direction and cannot be extracted again due to their design. These are particularly secure, but Torx® "Tamper Resistant" are also relatively, theft-proof screws that can only be opened with the help of a specific tool.

The WALTER product range

WALTER offers a wide range of cordless tools, which should not be missing from any household, garden or do-it-yourself workshops. For example, one of the high-quality WALTER cordless drill drivers should be present in every household. Whether for assembling furniture, hanging pictures, mounting TV sets or simply loosening screws.

Furthermore, WALTER also offers a versatile range of cordless gardening tools, such as the cordless pole pruner, the electric garden shears or the practical cordless rain barrel pump. With the help of these first-class gardening aids, the garden is maintained in no time and the personal feel-good factor is guaranteed!

You can find more tips & tricks for preparing the garden here.

WALTER also has a sufficient range of selected products available online in the handicraft and construction sector. These range from multifunctional tools, to hot glue guns and the mini cordless plunge-saw. So, you can start your next DIY project being perfectly equipped!

WALTER offers a wide and varied range of products to cover all your needs, so the right tool for both you and your wallet is guaranteed. Take a quick look at our large online selection and order yourself a new cordless tool from WALTER today!