6 best cordless grinders

Advantages and disadvantages of battery angle grinders

Let's start with the positive aspects of this tool.

Light weight. Even though the portable grinder has a battery, it weighs less than the models powered by the mains. Most of these models weigh between one and four kilograms. LBM with mains supply weigh at least three kilograms.
Mobility. This is the main advantage of battery-powered grinders. They can be used without an electrical network.
Relatively low noise level. LBM on rechargeable batteries, during operation, emit a sound within 35-65 dB. This is less than the standard models.
Low power. Under certain circumstances, this becomes an advantage. After all, a low power tool is easier to hold in your hands and perform a complex cut.
Convenient operation. No one will argue with the fact that it is much easier to work with a light grinder without a wire from the outlet than with bulky network angle grinders.

In some cases, the batteries from the angle grinder can be used on another portable power tool and vice versa. This can also be attributed to the pluses.

Now about the disadvantages of cordless angle grinders, of which there are many.

Price. Mobile angle grinders are more expensive than network models. A high-quality device of 18 volts, 3─4 Ah costs 15-18 tons. (data as of June 2019). Standard models will cost significantly less.
Low power. Here, the small capacity is seen as a disadvantage. Working with thick metal is undesirable for mobile grinders.
Short battery life. In most cases, 50-60 cuts can be made. Knowing about this weak point, many manufacturers sell their rechargeable angle grinders with two batteries. A full charge of these batteries takes approximately 2-4 hours.
Small assortment. Compared to conventional angle grinders, the choice of portable models is smaller. This is due to the lower demand for them. The smaller choice of accessories and spare parts for them is due to the same reason. And the repair of such a grinder in a service center will cost more.

Now let's look at some of the models of portable angle grinders on the market.

What to look for when choosing

Which cordless grinder do you use?

Ultra-compact Standard

When choosing a cordless angle grinder, it is necessary to take into account several parameters - this will allow you to purchase exactly the tool that is best suited for specific working conditions.

Power. If for network models it is usually indicated in watts, then rechargeable batteries use the voltage and capacity of the battery as a determining parameter. The question is debatable, since in practice a device with an 18-volt battery may be more productive than a brother powered by 24 volts. However, most often the dependence is still linear: the more current, the more powerful the device.

The number of revolutions. And this parameter directly indicates how fast the spindle will rotate and spin the disk. Usually, the larger the diameter of the disc, the lower the rpm, because at the same value, a point on a circle with a larger diameter will move at a higher speed. In other words, the faster the disk spins, the better the job is.

An extremely useful thing on grinders is the speed regulator. Indeed, for example, for a solid steel sheet, the faster, the better, but it is better to spin the disc on wood sparingly so that the material does not smoke and does not burn.

The weight. The case when hard does not mean good. Leading manufacturers are trying to lighten their tools, since the cordless angle grinder is a purely portable tool, and there are not so many models for the 230th disc and they are very specific. The indicator of 2.5 kg is a guideline - it is much harder not to buy grinders.

Metabo WB 18 LTX BL 125 Quick

This model is a professional tool equipped with high-current LiHD technology and electronic overload protection.The device is equipped with angle grinders and differs from competitors in the largest batteries and a brushless motor, which allows performing the maximum amount of work on a single charge. In order to achieve the maximum efficiency of the unit, it is enough to use standard batteries with a capacity of 5.5 A * h, moreover, practice shows that the device can work with batteries of lower capacity (4-ampere).

The device has a number of design features. In particular, the filters in the unit are easily replaced and installed back, which is especially important if we take into account that dust and gases emitted by the angle grinder gradually settle on the walls of the device and reduce its efficiency. The closed design reliably protects the machine motor from dust entering the gap between the armature and the starter. In addition, the motor in the Metabo angle grinder is protected by a fine mesh, which, although it does not protect against fine particles, acts as a reliable protection against potentially current-carrying dust on the contacts, which makes the operation of the device safer.

Lushm Metabo WB 18 LTX BL 125 Quick

The rotary angle of the unit has a flawless technical implementation of the unit, however, when using angle grinders, some problems may arise. So, with a heavy load, the contacts of the devices may overheat a little, which, however, does not lead to an automatic shutdown of the machine.

Among the design features of the model, mention should be made of the ability to rotate the battery by 270 degrees, which is important when using the unit in confined spaces. Simplifies the task of access to the cutting site and the elongated body of the angle grinder.

The external design features of the device are:

Quick-release flange nut that does not require the operator to use a wrench;
Spring ring that prevents the quick-clamping nut from loosening during braking;
The possibility of presenting the casing without the use of additional elements - just move it to the desired position and lower the lever
Anti-vibration front handle.

Thus, this model has the maximum functional equipment. For the convenience of the operator, it is also possible to fix the start button in the on position, and the spindle brake is able to stop the device within two seconds. The car showed flawless results when checking the quality of the safety system, including the most common problem - a jammed circle. By the way, in the event of emergency braking, the battery practically does not heat up.

So, the Metabo cordless angle grinder demonstrates excellent power, safety and reliability. The main advantage of these machines is their ability to be used to perform work with maximum loads.

Principle of operation and scope

An angle grinder is an electric hand-held tool that is designed to cut, grind, and grind products made from materials such as various types of stone, including concrete, metal, wood, and others. The grinder's device is not particularly complicated. However, it is necessary to navigate this issue in order to be able to carry out repairs or preventive cleaning on your own. The sturdy plastic case contains such basic elements as:

Wheel that regulates the speed;
Engine;
Start button
Frame;
Drive quick swap button:
Safety clutch;
Protective cover;
Working disk clamp nut;
Reducer housing;

The principle of operation itself is reduced to the conversion of the torque that comes from the spindle connected to the motor by means of a gear train. It is to the spindle that various attachments are attached that are necessary for a particular type of work. The tool body is made of high-strength plastic that can withstand impacts.By simply using different types of attachments, or rather, different types of abrasive wheels, you can perform completely different tasks, which significantly increases the scope of this tool.

The grinder is used when necessary:

Trim or cut out the tiles;
Cut metal sheets or rods;
Cut grooves in a brick or concrete wall for laying electrical wiring or water pipes;
Remove rust from the car body or a layer of old paint;
Sand wood or metal surfaces to a high degree of smoothness;
Clean welded seams;
Blunt sharp edges with chamfers.

A bit of history

The company, known today, was founded by brothers Eugen and Martin by the name of Hilti. She began her work back in 1941 in the small town of Shan (Liechtenstein). Initially, only a small workshop appeared, which was engaged in the production of tools for construction.

Significant profits have come to the company since the manufacture of the hand-held rock drill in the late 1960s. Further, Hilti expanded its range, and a large number of construction tools appeared on the market, which were distinguished by excellent quality and affordable prices. The company appeared in Russia only in the mid-90s. Today, Hilty is a large group of enterprises that are located in most countries of the world.

Encore AccuMaster AKM182

Choosing an inexpensive cordless angle grinder Enkor, unlike previous models, it was developed without the control of European manufacturers and is produced at Chinese enterprises, but under the direct control of a Russian customer. This, however, has absolutely no effect on the quality of the final product. The machine is as high-quality as its branded counterparts, has an affordable cost and excellent performance indicators. The tool does not have innovative solutions and has a rather unpretentious design, but at the same time it invariably successfully copes with the tasks assigned to it. So, the quality of the cuts is not inferior to the branded counterparts, and only when grinding the unit shows a lower productivity. At the same time, the model is easier to reboot, and when overloads occur, it quickly turns off.

All constructive devices in this unit are quite simple. Thus, the model has two standard battery motors, a cover and flange nut, turnkey mounting and a standard handle. The developers also abandoned the charge level indicator (it is absent in both batteries and the charger), and the charging speed of the device is inferior to brand models. Also, the unit has a different "consumption" - unlike the standard wheels for most models with a diameter of 125 mm, the manufacturer puts 115 mm discs on this model.

The device of the battery grinder Enkor AccuMaster has a not very convenient start button: it is tight and short, so keeping it constantly turned on is inconvenient. An absolute surprise is the rotary battery, which has a number of disadvantages. So, the sliding contacts used in the connecting unit heat up quickly enough during intensive use, and the contact ceases to be reliable, therefore the angle grinder turns on with a delay and only at a certain position of the battery. This design solution, together with placing the unit in an elongated case, should have simplified the performance of work in hard-to-reach places, but in practice much better results are obtained by using the AK1835 extension adapter, which allows you to hang the battery on a belt by connecting it with a cable to the angle grinder without forming unreliable sliding contacts.

The price of the model is from 3000 rubles.

LBM classification

The presented reviews on the domestic market of angle grinders can be divided into two categories - with brushless motors and 4-pole collector motors.It differs from them only "Encor", which is equipped with a 2-pole motor with a simpler device.

Compared to brushed motors, brushless motors are about 15% better at coping with the tasks assigned to them, so this review will focus primarily on their characteristics. However, even on a brushless machine, the battery can overheat (for example, when sanding at full load) and cause damage to the device. But when the units are exposed to low temperatures, the only problems in their functionality can be the capacity of the batteries.

The best grinders with a disc diameter of up to 125 mm

Such a tool is quite in demand for household needs. They can process stone, metal, wooden surfaces, plus the choice of consumables for standard angle grinders is wide enough. In this category, there are three models that have been selected among a dozen applicants for their quality.

De Walt DWE 4215

Compact, machine for standard operations. It easily cuts stone, metal, concrete and is able to quickly sand drywall, wood or plastic. Thanks to the ergonomic swivel handle, the grinder is comfortable to hold in your hands. The modern motor protection system will ensure that there is no dust, and the overload protection will prevent overheating. The simple technology of adjusting the position of the hood protects against sparks and dust. The work equipment is easy to change thanks to the spindle lock. The De Walt start button is on the side, customers note that it is quite convenient, since it cannot be accidentally touched.

Dignity

Low weight;
Soft move;
No vibrations and beats;
Low noise level;
Frost-resistant cable.

disadvantages

Short power cord;
Abrupt start.

Buyers advise not to hold the grinder with one hand, especially at the start, as it can slip out.

Bison UShM-125-950 M3

This nominee, like the previous one, is intended for household needs. Its power is small, only 950 W, but the device easily copes with cutting and grinding wood, metal and plastic products. Dust-proof elements provide reliable protection for critical mechanical components, and a spindle lock facilitates the installation and removal of consumables. The Bison works with minimal vibrations, the machine is relatively quiet, not heavy. The tool head can be rotated 90 degrees to handle corner seams. Plus, an additional handle is provided, which ensures ease of use.

Dignity

Latching switch;
Switchable carbon brushes;
Good build quality
Big guarantee from the manufacturer;
Low price.

disadvantages

No overload protection;
There is no adjustment of the position of the casing.

Buyers recommend that the Bison work no more than 10 minutes, after which he must be allowed to rest. It does not provide for the support of constant disk revolutions under continuous load.

Military AG600

Military recognized as the best grinder 125 mm according to customer reviews. The tool is universal, it can work with different accessories: discs, wheels, brushes and is suitable for cutting and grinding. The angle grinder does not heat up during operation, the protective casing is made of reliable metal, which protects users and the tool from damage. There is also a two-position auxiliary handle that can be locked to the right or left. The handle is rubberized, which gives additional convenience in work and prevents the machine from slipping. The Military head is capable of rotating up to 11,000 rpm, which allows you to quickly clean surfaces or cut metal.

Dignity

Low weight;
Smooth start;
Good balancing;
Easy fixation of the spindle;
Long power cord.

disadvantages

Tight power button;
Under load, it loses momentum a little.

Some users consider the disadvantages that the grinder starts to warm up under load.Considering that the instrument is low-power (600 W) and the price is small, this claim is not substantiated, therefore the experts did not attribute this to disadvantages and simply recommend not to overload the instrument.

How to use?

If possible, you can connect the charger supplied with your grinder to a nearby outlet. It's always a good idea to have replaceable batteries: while you are using one battery, the other is being charged.

If the machine has a speed control, it is best to use the largest one possible for the specific abrasive disc. Cutting should be fed smoothly and without excessive pressure. The misalignment of the tool threatens not only that the cut will come out uneven, but also that the disc may collapse. It is very dangerous.

For coarse sanding, if a significant layer of material needs to be removed, a roughing disc should be used. In this case, the tool must be held with some inclination to the surface. Make sure that no deep grooves are left on the work piece. Under no circumstances should cutting discs be used for roughing. They are too thin and break at the slightest lateral bend.

If, while working with diamond discs, you notice a long sheaf of sparks, then this means that the tool is dull. You can restore its suitability by simply making several slots with such a disk in any hard material (for example, ordinary brick). A continuous ring of sparks around a conventional disc indicates complete wear of the abrasive surface. It is better to replace such a disk with a new one.

See below for more details.

Bulgarian rating

Before compiling the rating, a thorough testing of power tools was carried out, which revealed their advantages and disadvantages. Experts and real buyers helped to draw up a full review and give objective ratings. The selection of nominees in the TOP was carried out according to the following criteria:

Power;
Functional;
View;
Disc diameter;
Number of revolutions;
Number of handles;
Price.

Having considered each parameter in detail, the rating specialists were able to choose the best grinders from several dozen applicants. For the convenience of readers, all nominees are divided into five subgroups.

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LBM operating rules

Repairing a grinder is quite costly. To delay this moment as much as possible, it is necessary to handle the instrument correctly. Let's consider the main points:

Do not remove the protective contour over the abrasive wheel unless absolutely necessary. If the need arose nevertheless, be sure to use safety glasses so that small particles of abrasive do not damage the organs of vision. In addition to your own protection, you need to ensure that the tool itself does not touch anything with its unprotected sides;
It is not recommended to process chipboard materials with a grinder, only with a hacksaw or a saw;
When working, you need to grip the tool very tightly. If the disc gets stuck, the grinder can fall out of your hands and cause serious injury or damage;
When working with metal surfaces, sparks and small scale are inevitable. It is necessary to protect the skin of the hands and eyes and be careful not to get sparks on wiring or flammable materials;
When cutting any material, in no case should you put pressure on the cutting object in order to speed up the process. It is necessary to press only on the tool and then, not too hard.

Preventive care has not been canceled either. It consists in periodic cleaning and lubrication of the instrument from the inside, for this part or all of the instrument is disassembled completely, dust is blown out and surfaces that need lubrication are processed. Replacing small parts that wear out quickly is very easy. But if you do this in a timely manner, you can protect more critical and expensive parts from wear and tear.

If the device refuses to start after pressing the button, you do not need to immediately try to disassemble it completely.It is worth starting to identify the problem from the simplest places. For example, to begin with, check the power cord, perhaps there is a strong bend somewhere, then replacing the power cord will solve the problem.

If the wire and plug are intact, it could be the trigger. It must be disassembled and cleaned, or replaced completely. If too much building dust has accumulated inside the appliance, this can also cause a failure. To eliminate it, it is often necessary to replace the brushes, which are so dirty that they simply stop receiving electric current.

Makita DGA504 RME

This device belongs to the category of professional units. Equipped with a Li-Ion rechargeable battery, it charges in just 45 minutes, and has a number of design features that provide both affordable cost and excellent technical characteristics. So, the unit is equipped with a brushless motor, electronic overload protection, a charge level indicator on the device.

Grinder Makita DGA504 RME

The results of using this model can be compared with those of other angle grinders belonging to this group, however, as noted above, the device has a lower cost. The reduction in price was achieved not only due to the lower capacity of the batteries, but also due to the so-called "body kit", that is, the greater ergonomics of the unit. So, the front handle and flange nut on the device are ordinary, the indicator is located not on the handle, but on the device itself (that is, you can find out its state only by turning on the equipment).

By the way, the quality of the indicators on this unit often raises criticism, since if there is only 50% of the charge, the device can inform that it is fully charged. There is no spindle brake on the unit, therefore, after shutdown, the wheel continues to rotate by inertia. But at the same time, the device has its own security system, which triggers instantly when the circle is jammed. Having equipped the device with a minimum number of technical solutions, the developers still took care of the convenience of its operation. So, the start key can be fixed during operation, which is especially important if cutting or grinding has to be performed in an uncomfortable position.

The indicated design features of the Makita battery grinder require that the security systems be as reliable as possible. A fixed button in an emergency situation will not allow you to immediately stop working, so the developers have equipped the Makita angle grinder with a reliable security system that can be activated within a couple of seconds. At the base of the handle of the machine there are triangular inserts that look like design elements, but in fact act as filters and are located on the air intake grilles. The device has a relatively low spindle speed while maintaining decent performance. The battery charge is also economically consumed, ensuring uniform operation of the unit even at high loads. Accordingly, unlike collector angle grinders, this device does not turn off when the batteries are overheated.

Despite everything, choosing a Makita battery grinder, you are purchasing a proven, cost-optimized brand. Prices depend on the model, start at 20,000 rubles.

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