Comparison GARDENA TCS 720/20 8868-20 vs GARDENA TCS Li-18/20 8866-20

— Power grid. Powered by a conventional 230 V household mains. This option allows you to create quite powerful models, which are also much cheaper and easier to operate than gasoline ones, are quieter, weigh less and do not create exhaust gases. Of course, you will need an external power source for operation, and the battery life of the tool will be limited by the length of the power cord. At the same time, many modern "network" brush cutters are equipped with very long cords — about 20-30 m — which, moreover, can be supplemented with extension cords; and the 230 V network is distributed almost everywhere, from elite private houses to small summer cottages. However, the power cord has another significant drawback: it can create inconvenience when moving around the site (especially if there is thick grass hiding it). In addition, a tool with such a power supply has increased safety requirements: it cannot be used in wet weather, and special care must be taken during operation so as not to snag the power cable. Also, the power of electric models is generally slightly lower than that of gasoline ones.

— Battery. Powered by its own built-in battery. In terms of their main advantages, such models are similar to network brush cutters (see above): they do not create excessive noise and exhaust gases, are easy to maintain and cheap to operate. At the same time, the battery gives one important advantage — ba...ttery life: the tool does not require a constant connection to the network and works without a power cord, which ensures freedom of movement. On the other hand, such hedge trimmers are quite expensive, have a lot of weight (due to the battery), and their power is low and suitable only for relatively simple work. In addition, it is necessary to mention the limited period of work — in most models it is about 40-50 minutes, and even less if the working nozzle is heavily loaded or dirty. When the battery runs out of charge, it will have to be charged again, which will require a power source and can take quite a long time. Therefore, it is worth specifically looking for a battery model only if complex work is not planned, and freedom of movement plays a decisive role for you.

— Gas engine. The main advantage of a petrol engine can be called high power. Due to this, such brush cutters easily cope even with complex tasks that are beyond the power of electric models. In addition, such engines do not depend on external power sources and require only the presence of fuel in the tank to operate. However, gasoline tools have a number of disadvantages: heavy weight, high noise level, harmful exhaust gases, as well as difficulty in maintenance and high fuel costs. Therefore, this type of engine is found mainly in professional models that need to combine maximum battery life with high performance.

Hedge trimmer motor power expressed in watts.

The performance of the tool primarily depends on the engine power, and this concept includes both the overall speed of work and the ability to cope with difficult tasks like cutting thick branches. Therefore, when choosing, it is necessary to take into account both the general volumes of the planned work and the material with which you will have to deal. For example, a powerful hedge trimmer may be needed even if it is only a few metres of hedge — if the branches in this hedge are quite thick. On the other hand, "more powerful" does not always mean "better" — after all, this parameter affects the weight, energy consumption (or fuel consumption) and the price of the tool.

If we talk about specific numbers, then the optimal power for most household tasks will be about 400-600 watts. Battery models (see "Power"), designed for small amounts of work in simple conditions, may have less power, and in gasoline models (see ibid.), on the contrary, it can reach 900 – 1000 watts.

In addition to watts, power can also be expressed in horsepower; this designation is traditionally used in gasoline engines. 1 HP approximately equal to 735 watts.

The type of battery installed in the battery-powered hedge trimmer (see above).

— Ni-Cd. One of the first types of batteries used for power tools. Nickel-cadmium batteries are well-suited for heavy loads, have quite a decent capacity per unit weight, while charging fairly quickly and are resistant to temperature extremes — the latter is important, given that brushcutters, by definition, are used outdoors. On the other hand, such batteries have a number of significant drawbacks, the most important of which is the “memory effect”: if the battery is started to be charged without completely discharging it before, it will accumulate less energy (as if “remembering” that part of the charge was not needed last time). (hence the name of the effect). In addition, some components of Ni-Cd cells are considered environmentally unsafe. As a result, this type of battery is considered obsolete and is gradually being replaced by more advanced options.

— Ni-Mh. Nickel-metal hydride batteries were created as a development of nickel-cadmium batteries, in an attempt to eliminate their main shortcomings. Such batteries are practically devoid of the "memory effect", they use safer materials in their construction, and at the same time they have all the main advantages of the original technology — in particular, reliability and resistance to temperature extremes. Of the shortcomings, one can only note the need to comply with specific rules for long-term storage.

— Li-Io...n. The most advanced type of modern batteries. Lithium-ion batteries combine small size and weight with high capacity, charge quickly, are practically not subject to the "memory effect" and are generally unpretentious in operation (besides, many of these batteries have recently built their own controller that optimizes charge-discharge cycles) . At the same time, they are sensitive to low temperatures and are more expensive than other types.

Operating voltage of the battery in a battery-powered hedge trimmer (see above). This parameter is usually selected by the manufacturer according to the characteristics of the engine: the greater the power, the greater, the battery voltage is likely to be. In fact, voltage data may be needed only if the battery fails and it will be necessary to replace it with an equivalent one. In addition, there are formulas that allow you to roughly estimate the battery life depending on the battery voltage, its capacity and the power of the tool; they can be found in special sources.

The capacity of the battery that comes standard with the battery-powered hedge trimmer (see above). Expressed in amp-hours, one ampere-hour means that the battery is capable of delivering 1 amp for 1 hour.

Last but not least, the battery life of the tool depends on the capacity of the battery. However, it is impossible to directly evaluate the battery life of a brush cutter by this parameter: the fact is that it depends on a number of other factors, ranging from engine power and battery operating voltage to the degree of complexity of work and contamination of the nozzle. Therefore, it makes sense to compare different models with each other in terms of battery capacity only if they do not have significant differences in other characteristics. But at the same time, brush cutters with a capacious battery a priori allow the device to work more.

The name of the battery that is compatible with the device. It helps to buy a spare or find a suitable one in case of a breakdown of the main one.

Approximate noise level produced by the hedge trimmer in normal operation. This parameter allows you to evaluate how comfortable it will be to work with the tool: the lower the noise level, the less discomfort it causes for the operator and others, and the lower the likelihood that special hearing protection will be needed during operation. At the same time, note that loud noise is an inevitable side effect of high power — it would be too expensive and difficult to make a powerful and low-noise tool. In addition, this figure is only approximate. Firstly, different manufacturers may indicate it differently: for idling, for full speed, for half power, etc. Secondly, the actual volume of work may also differ from the claimed one due to the peculiarities of a particular situation: for example, working with thick branches leads to an increase in the load on the engine, which can also affect the noise level.

Another specific point is that the decibel used to measure this indicator is a non-linear value: an increase of 1 dB corresponds to an increase of 1.26 times, 3 dB — 2 times, etc. Therefore, to assess the loudness of work, it is easiest to use comparative tables. Here is one of the simplified versions of such a table for the range in which most modern hedge trimmers work:

65 dB — loud conversation at a distance of a metre;
70 dB — loud conversation of several people at the same distance;
75 dB — shout from the same distance;
80 dB — the ringin...g of a mechanical alarm clock, a loud cry at a distance of 1 m;
85 dB — loud screams at a distance of 1 m;
90 dB — heavy truck or freight car at a distance of 7 m;
95 dB — subway car at a distance of 7 m;
100 dB — noisy industrial shop.

The total weight of the brush cutter. Usually indicated for a fully equipped tool, with an attachment installed and, in the case of a petrol engine, a full tank of fuel; however, there may be exceptions. Usually, the relevant data is indicated in the official documentation.

This parameter is important, first of all, taking into account the fact that the tool during work will have to be kept on weight most of the time. Accordingly, the lighter the brush cutter, the longer you can work with it without interruption, the less often you have to rest. On the other hand, a large weight also has its advantages: a heavy tool is more stable and does not “tear out of hand” as much under high loads on the nozzle.