Cordless Power Drills
A cordless power drill is an electric drill that is commonly used for drilling holes in places that have no nearby power outlet. They run on a rechargeable battery, but ultimately this battery will need to be recharged so it is good to have a spare on standby. Cordless power drills usually come with a built in clutch (to stop the driver bit from spinning out the recessed head of a screw) and also a hammer setting for drilling masonry. There are other types of cordless power drill available such as high torque varieties for drilling large holes, and even a right angle drill for those hard to reach spots.
Cordless drill technology has greatly advanced over the years and the power available has increased from the original 7.2 volts, right up to 36 volts which delivers the power of a corded drill. However, it is recommended that you get a power drill somewhere in between 12 and 18 volts, as this would be ample for everyday projects and will provide all the drilling power you need.
The default rechargeable battery that comes with a cordless power drill is a ni-cad battery (Nickel Cadmium). A ni-cad battery is cheaper than the alternative, and will last longer in terms of charge/discharge cycles. However, nickel-cadmium batteries have limited life, are self-discharging even when not used, and can internally short circuit due to dendrite growth. In more recent times, the Nickel-Cadmium battery has been superceded by the Lithium-ion battery. These batteries are lighter, have shorter charging times, and have longer life. Some negative aspects of these kinds of batteries is that they don’t like to work in very cold temperatures and in general are more expensive. You should weigh these factors up carefully when deciding which type of battery to opt for.
All in all, a cordless power drill may not be as powerfull as a corded drill, however the advantages of not having to plug into mains power cannot be underestimated.
