- Choosing the type of saw for the purpose
- Difference in battery types
- Benefits of a branded tool
- Ergonomics and autonomy
- Disadvantages of cordless tools
With the advent of lithium power supplies, the cordless tool has moved to the next level. This is especially true for saws: without a network connection, the ease of use and freedom of action are much higher. We will tell you whether buying such a tool is really worth the money spent.
Choosing the type of saw for the purpose
There are several types of sawing tools and the first step to a profitable purchase is to match the tasks. It’s not as easy as it sounds: you can cut anything and in any conditions. But there are still some patterns.
Let’s start with the most popular saber saws. This tool has the most extensive range of tasks, from tree pruning to fine carpentry and aerated concrete block molding. Until recently, the main disadvantage of reciprocating saws was considered their low mobility, because the high ergonomics of this tool simply “screams” about the need to get rid of the power grid. With the advent of self-powered devices, this problem has been completely resolved..
Battery chain saws are also very popular. It is almost a complete replacement for the petrol engine and even more: thanks to the ease of maintenance, the electric saw gains new advantages. There are no problems with starting in cold and humid weather, the work does not interfere with exhaust gases and the noise of a gasoline engine. There are also some drawbacks: with a high output power, the charge is only enough for a fragmentary sawing of a small tree. Therefore, you have to keep the charging station close at hand all the time..
More specialized tools include cordless jigsaws and circular circular saws. By and large, the only benefit from battery power is one: the power cord does not interfere with work. In addition to increased ergonomics, cordless circulars and jigsaws do not have any outstanding features, although they allow you to work on non-electrified objects and in hard-to-reach places..
Difference in battery types
When choosing any cordless tool, the most important criterion is the type of batteries. It is impossible to give preference to any particular class of batteries, it all depends on the type of instrument and the specifics of working with it.
In general, two types of batteries can be distinguished – nickel and lithium. The former, in turn, are divided into two separate classes: cadmium and metal hydride. Nickel batteries are gradually being replaced from the market, although they remain quite popular due to their low cost. Lithium-ion batteries have more impressive performance, but their high price and short lifespan make them unprofitable in some situations..
In the context of a saw tool, batteries can be considered according to several criteria:
- Operating temperature range. At subzero temperatures, the power of the batteries is noticeably reduced. Ni-MH cells are considered the most sensitive to frost, lithium batteries are somewhat better in this regard. Li-Ion power supplies are restored to the state of charge when heated back to room temperature, which cannot be said about metal hydride batteries. NiCd batteries feel the most energetic: some noticeable drop in power is observed at temperatures below -30 ° С.
- The mode of operation of the tool determines the degree of influence of all other factors. For example, if you need to use the saw for 30–40 minutes in the cold and then return the tool to the workshop, there will be no noticeable drop in power. Of particular importance is the phenomenon of self-discharge, inherent in all batteries with the exception of lithium. If the tool is used from time to time, only Li-Ion batteries are able to immediately start working. Nickel batteries lose an average of 20% of their capacity per month, and they need to be “used up” completely before being put on a charging station.
- Tool power. Batteries differ not only in capacity, but also in voltage and discharge current limit. Again, Li-Ion batteries are the best in this respect, NiCd confidently compete with them. You need to understand that for a jigsaw and a reciprocating saw, high consumption currents are not characteristic, but chain saws are a rather powerful class of tool that requires full return from the batteries. In general, batteries with a voltage of 18 and 24 V are considered the most suitable for sawing tools for jigsaws, circulars and sabers, for chain saws this bar is slightly higher – 36 V.
- Ease of use and maintenance. Since the main advantage of battery power is expressed in increased ergonomics, this “bonus” should be as tangible as possible. All batteries, except for lithium, require periodic maintenance. In turn, nickel cells are not sensitive to overcharge and can be charged from the simplest stations. In this case, in addition to monitoring the charging current, lithium batteries also require accurate balancing, otherwise their service life can be reduced by 2-3 times..
Benefits of a branded tool
When choosing a power tool, we evaluate it according to such parameters as reliability, accuracy and cleanliness of processing, availability of components and consumables. When choosing a cordless tool, you should pay attention to some other aspects..
The first of them is how competently the power scheme is arranged. Most of the tools made in China have a direct connection of the engine to the battery through a button with a speed control. This scheme impresses with its simplicity and reliability, but at the same time there is a great risk of taking the batteries into a deep discharge. The difference between the brand tool is the presence of a discharge circuit indicator and the exact correspondence of the battery to the operating parameters of the engine used.
Another important feature concerns the charging station. In addition to the fact that the charger of the upper price category tool supports boost charging modes, they also have on-the-fly charging current adjustment devices, which increases the battery life. Naturally, the quality and durability of expensive tools and batteries will be on the same level. And one more important feature concerns the service life: in a cordless tool, it is almost always the battery that fails first. If the tool is manufactured by one of the well-known brands – the battery pack is usually designed for use in several models and the probability that it will be discontinued is somewhat lower.
Ergonomics and autonomy
If for a screwdriver correct balancing and a secure grip is a matter of only convenience, then for sawing tools this is a safety requirement. On average, a cordless saw is always slightly heavier than a power or gasoline saw, and battery placement is not always beneficial. The tool should be firmly gripped and the weight of the battery should be able to balance the force exerted during operation. This is especially important for jigsaws and circular saws, which usually only have to be operated with one hand and in an uncomfortable position..
But that’s not all: pay attention to the correspondence of the power and capacity of the battery. Knowing the operating voltage, it is easy to recalculate the operating current, and from it to calculate the time of continuous operation. The battery capacity does not have to match exactly the consumption. It is imperative to take into account such a parameter as the duration of the inclusion so that the instrument has time to rest.
Disadvantages of cordless tools
The choice between cordless and chain saws is a compromise between autonomy and performance. With all the convenience, the power of the battery-powered tool is always 20–25% lower than that of the representatives of the network line in the same weight category. You either have to put up with this, or get a small gas generator.
Another problem is the limited resource of work. All batteries are subject to degradation, which develops more actively as the intensity of use increases. So, even with an extremely rare start-up, a high-quality lithium battery will last no more than five years, while nickel cells have an actual service life even less – 3.5–4 years. In view of this, it is advisable to purchase tools of only common series with a battery base that extends to other models. Or, you can pay attention to the format of the batteries in order to replace them after the final loss of performance. Among this kind of disadvantages is a decrease in power and efficiency in proportion to the drop in battery voltage – sometimes even at half the charge, the tool simply ceases to cope with the tasks assigned to it.
Once again, we recall ergonomics: for chain and reciprocating saws, the weight gain is not as critical as for screwdrivers, because the weight of the battery is compensated by the decrease in the weight of the motor unit. And yet, the battery must be well placed. So, the location of the battery pack in the back of the handle is considered not a particularly good solution, it is much better if the battery is fixed at the bottom or side of the case.