An introduction to drill drivers: The drill driver is the most basic cordless drill (see rotary drills for their mains equivalent). They are used for drilling holes in wood, metal or plastics as well as driving screws.
To choose between drill drivers: The key consideration when choosing a drill driver is the maximum drilling diameter required. Drill drivers with 1/4″ hex drives; the drill bit fits straight into the machine rather than tightened into a chuck. 13mm refers to maximum drilling diameter in steel, you can use a larger drill bit for plastic & wood providing it has a 13mm or smaller diameter shank to fit the chuck. A keyless chuck is tightened by hand.
To make sure you’ve got the right drill driver – 13mm keyless chuck: Choosing the right battery: Cordless (or battery powered) tools have various chemical battery types; Li-ion is the latest technology, prior to that it was Ni-MH and Ni-Cad was the original. The higher the Ah (Ampere hours) the longer the interval between charges; the fewer times you recharge a battery the longer it will last. Some cordless tools can also come without batteries – also referred to as naked, bare units or body only. These tools are supplied without a battery or charger and more often than not without any accessoires. As a result they are significantly cheaper in price.
Most professional drill drivers have a variable speed function and a variety of torque settings. Additionally there is often a choice between single, 2 or 3 speed gears; a low speed and higher torque setting is used for screw driving whilst a higher speed is used for drilling metal or wood for example. Combi drills and impact drivers have higher torque settings.