The purchase of a new cordless screwdriver is likely to bring desperation to a multitude of people. Numerous parameters have to be taken into account, of course first of all the battery. Because without a powerful battery brings the whole device nothing.
In addition, there are differences in engine performance, in handling or ergonomics and other options such as impact mechanism and torque are parameters that need to be clarified in advance. Not everyone needs the full range of a professional device, but you should go deeper into the bag and tend more to the brand manufacturer, so that in the future, you have secured and do not have to buy twice.
The most important parameter when purchasing is undoubtedly the performance of the battery. Without enough battery power and battery capacity, working quickly is no fun and the work is unnecessarily lengthened. For constant use, as on a construction site, it is also a no-go! In earlier times, however, it was the case that the batteries had discharged very quickly deep and a spare battery always had to be ready. Fortunately, these times are gone, thanks to advanced lithium-ion batteries. Even if they are not used for a long time, they keep the energy constantly stored with marginal losses.
Of crucial importance are now the electrical voltage, which is given in the unit volts and the electric charge with the unit Ah (ampere hour). The cordless drills available on the market range from 1.5 Ah to 2 Ah and 3 Ah to 5 Ah or 5.2 Ah (Festool DRC 18/4 Li 5.2).
Single batteries with 6 Ah and more can be purchased separately. This size is only of limited importance, because it can not be read exactly how rich the respective battery will be. It provides information on how long the battery can work or how long a charge will last. The larger the ampere indication / number, the longer the battery will last. This means: longer work and less loading!
When the electrical voltage (volt) comes into play, you have a solid foundation to judge the performance of a battery. This ranges from cordless screwdrivers of 3.6 volts (mini cordless screwdriver) over 7.2 volts, 10.8 volts & 14.4 volts to 18 volts and even 20 volts. However, differences between the manufacturers must be considered, although „lithium-ion battery“ is written.
The larger the voltage is, the more power is usually delivered by the cordless tool. Why some cordless screwdrivers have 12 volts and other 18 volts is simply up to the device itself, as the battery size in relation to the engine was chosen by the manufacturer.