A battery screwdriver is a cordless, battery-powered screwdriver. Most of these tools are also capable of functioning as cordless drills as well. They are available in many different styles, some of which are especially well-suited to extended use or designed to operate in small or unusual spaces. These tools are generally powered by rechargeable batteries, which come in several varieties, and are typically either inexpensive or able to hold a charge for a long period of time.
Electric drills and screwdrivers are very useful tools. Hand-tool versions of both exist and are generally used for certain specialized applications or for small jobs. Power drills and screwdrivers can be used for a much longer period of time and do not place the same physical demands on a user, particularly when working at odd angles. Corded electric screwdrivers must be used for jobs where a great deal of drilling must be done, as this can drain a battery very quickly. The battery screwdriver has become the standard tool for most work with screws and most small drilling tasks, however.
The inner workings of a battery screwdriver feature an electric motor which draws power from a battery pack. Many models have variable speed and clutch settings. The speed settings allow the bit to spin faster for drilling. Clutch settings are useful in making sure that the battery screwdriver does not exert too much force on a screw, which could lead to the screw being pulled entirely through some softer materials such as pine or plywood.
Most types of battery screwdriver use a keyless chuck system. When tightened, this can hold drill or screwdriver bits up to a certain size. Some smaller screwdrivers cannot accommodate larger drill bits and would be unsuitable for tasks that require these larger bits. A few types of screwdriver can only use six-sided screwdriver bits.
Motors vary in size and power. Larger motors are more powerful but require more electrical energy, and thus require larger battery packs. Smaller motors may not be able to complete work on some jobs, but are lighter and more portable. A battery screwdriver is rated based on the voltage, or electrical force, that it uses. Higher numbers are more powerful, and any battery screwdriver rated at 18v or above is suitable for very heavy-duty work.
Battery technology has changed greatly in recent years. Some types of battery screwdriver use nickel-cadmium batteries. These sorts of rechargeable screwdriver are inexpensive but do not have as much power or hold a charge as efficiently. They are perfectly suitable for small tasks, however, and tools that use them are typically quite affordable.
A lithium ion screwdriver, on the other hand, uses state-of-the-art battery packs. These are more expensive but have more power and hold a charge more efficiently. This type of screwdriver is ideal for larger projects.