Before everyone who independently makes repairs to an apartment, a garage, a summer house, sooner or later there is such a problem as the choice of a screwdriver. Today, the market offers a large selection of these convenient cordless electric tools. Some put a nozzle for working with screws on a drill, but this is not always a convenient replacement, especially if you need to work all day. A good cordless screwdriver has many useful functions that cannot be replaced with any attachments.
In order for the choice of a screwdriver to be correct, you need to determine its criteria. The most important thing is to establish the degree of frequency of use of the tool. We need to figure out what operations will be performed and how much time a day without a break the tool will be used. If the intensity is close to professional, then the choice of a screwdriver should be stopped on brands like Bosh and Makita.
What characteristics of the tool should you pay attention to first of all? This is voltage, capacity and speed. The main part of the screwdriver, allowing it to work without a power source, is the battery. Its main characteristics are voltage and capacitance, the first is measured in volts (V), and the second in amperes / hour (Ah). The voltage indicator is the battery power, and the capacity is the operating time after charging. For continuous operation , batteries with a capacity of 1.3 Ah or higher and a power of 12 V or higher are suitable. It’s better to buy two at once. One works until the battery is completely discharged, the other charges, and it is better to charge fully, not partially. In this mode, it will last much longer.
As for speed, it is better to stop the choice of a screwdriver on a two-speed tool. Low speed at high power, as a rule, is used for the twisting procedure, and high speed - when drilling.
In inexpensive models there is no “stop” button. In the more expensive it is. If you press it, the screwdriver stops and does not turn, which allows you to change the nozzle. Well, if you can set the torque. This will allow the screwdriver to stop automatically and not twist the screws.
When choosing a screwdriver for the house, you need to be sure that it can withstand a fall from a two-meter height, because modern models have a sufficient strength limit. Caring for the tool is simple: you need to lubricate and clean the cartridge from time to time, avoiding the ingress of moisture, debris, sand or dust. It is important to ensure that the screwdriver does not overheat. If he "does not pull", you need to slow down or use a more powerful tool.
Choosing a cordless screwdriver also means choosing a type of battery. The market offers NiMH (nickel-metal hydride) NiCd (nickel-cadmium), and Li-Ion (lithium-ion).
NiCd has undeniable advantages, and there are three of them: cheapness, the largest number of recharges, respectively, the longest duration and the largest amount of current delivered. The disadvantage is the “memory effect”, a quick failure when the battery is not fully discharged and charged. It is recommended to store such batteries in a discharged form at positive temperature. NiMH batteries, on the contrary, are recommended to be stored in a charged state.
A Li-Ion battery has such a disadvantage as aging, even if it is not used. Within two years, most of the battery capacity is lost.
Today, there are models of screwdrivers that can run on batteries of various types.
The most toxic is the production of nickel-cadmium batteries. On the territory of the European Union, their production is prohibited. The newer and less toxic and environmentally friendly is the production and then disposal of nickel-metal hydride batteries.