Drills, Cordless

With no trailing flex getting in the way, cordless drills are flexible and convenient. But make sure you choose one that won't run out of energy before you do.

A cordless drill, powered by a rechargeable battery, is a good choice for a first electric drill. They're safer to use than one with a flex trailing behind you, and are great for those hard-to-reach places and for working outside. They can also be used as an electric screwdriver, taking the work out of putting in and taking out screws.

If you're into DIY in a serious way, you'll need a more powerful mains-powered drill for really tough tasks, especially if you do a lot of drilling in masonry. But a cordless drill can still be an invaluable extra.

We've tested 21 cordless drills, priced from Ł30 to Ł199, and found that you don't need to go for the most expensive model to get the best performance.

Features

Voltage
This is directly related to the power of the drill. Voltages range from 7.2 volts to 24 volts. For our test, we've concentrated on 9.6-volt to 18-volt models as these are most widely sold.

A higher voltage drill delivers more power, so you'll finish the job faster. But voltage alone doesn't determine performance. One of the best models on test - the Metabo BST 12 Plus - was a modest 12 volts.

Voltage also affects the drill's weight. As a general rule, the higher the voltage, the heavier the battery. A larger battery doesn't necessarily mean the drill will run for longer. A 9.6-volt battery may run for just as long as an 18-volt battery before it needs recharging, but the higher voltage drill will get through more work in that time.

Chuck type
All the models on test had keyless chucks, allowing you to change the drill and screwdriver bits without having to use a special key to release and tighten them. Some models also had 'automatic shaft arresting'. The spindle automatically locks into place when the drill is off, making it easier to turn the chuck.

Gears
Gears transmit power from the motor to the chuck and the drill bit. The simplest and cheapest drills generally have one gear but it's worth paying extra for the second gear, especially if you'll use the drill for screwdriving. In a two-speed gearbox, the first gear offers greater torque (twisting force) at lower speeds. This gives you better control of the drill, making it easier to start holes neatly and to drive in screws. It's also better for drilling larger holes in masonry.

The second gear is for drilling at higher speeds into wood. When drilling large holes into wood, it's best to drill a pilot hole with a smaller drill bit first.

All the drills have a reverse gear - useful for undoing screws or freeing stuck drill bits.

Variable speed
Look for a drill with variable speed control. The speed increases as you squeeze the trigger, allowing you to match the speed to the job. You can start to drill slowly and gradually increase the speed, making for a more accurate and neater hole. All the drills, except the Black & Decker HP96K Esprit and the Black & Decker KC14XC, have this feature. We found that the variable speed on the Hitachi DS14DVF was erratic and hard to control.

Drills with 'fast stop' will stop quickly when the trigger is released. This gives you greater control, making for a neater result.

Hammer setting
Six of the drills have a striking action that makes it easier to drill into concrete. These drills are built to pound or chip - at 10,000 beats per minute or more - at the same time as they drill.

Useful extras
All of the Bosch models have a magnetic surface on the top of the drill for holding small drill bits, screwdriver bits or screws. A spirit level is integrated into the Black & Decker HP96K Esprit, the Black & Decker HP122K Esprit and the Performance Power Pro 12v.

Our Tests

We drilled holes into hardwood (beech), steel and masonry, measuring how long it took and how efficient the drill was at using power. For consistency, we used standard drill bits, rather than the bits that came with the drills.

We drove screws into and out of softwood (pine) and steel, measuring how long it took and how effectively you could control the speed and torque.

If a drill had a hammer action, this was tested by drilling holes into concrete. We found that cordless hammer drills have improved greatly since we last tested them. Only the Power Devil PDD2184KKLH model did poorly. The rest coped well with our tough tests, although they're still not a match for a mains-powered version.

Battery Life

One downside of a cordless drill is the need to charge it up before use. It won't hold its charge indefinitely, so if you aren't going to use it regularly, you'll need to plan ahead. If you're an occasional user, you'll be best choosing a model that doesn't take too long to charge - most take an hour, but the slowest on test, the Black & Decker KC14XC, takes eight hours.

Two of the Black & Decker models - the HP96K Esprit and the KC14XC - don't have an indicator to show the drill is charging.

Most of the drills suffer from poor battery life. Those that last the longest before needing recharging are the Performance Power Pro 18v and the Wickes 505-097. It's worth buying a spare battery - several drills did come with a spare. You can have one battery on charge while the other is being used, so there's no risk of running out of power in the middle of a job.

If the drill has 'energy control', you can check how much energy is left in the battery. For the drills that had this feature, we checked to make sure it was accurate. They all passed the test.

Ease of Use and Endurance

A panel of experienced DIY enthusiasts, including a left-handed person and someone with small hands, assessed the ease of use of each drill. They considered the weight, balance, and design of the controls, and checked how easy it was to insert and remove drill bits, and to change the battery.

The weight is largely down to personal preference. Some drills are heavy, and you may find them more difficult to control. But if you can cope with the extra weight, it can help the drill's performance with more demanding tasks, particularly when using the hammer setting, because it helps to make the drill feel more stable. Taking this into account, our panel judged that only the heaviest drill - the Performance Power Pro 18v - was too heavy to be used comfortably.

The balance of the drill affects how heavy it feels in use. A heavy, well-balanced drill may be easier to use than a lighter one that is poorly balanced. Handle design has a big effect on the balance of the drill. Drills with a T-shaped handle are usually easier and more comfortable to use than those with a 'pistol-grip'. The advantage of the T-shape is that the weight of the battery is centred and the drill feels more balanced. Only two - the Black & Decker HP96K Esprit and HP122K Esprit - have pistol grips. Of the drills with T-shaped handles, all except the Wickes 505-097 are well balanced. If you have small hands, you may find the handle on the Performance Power Pro 12v and the Ferm FSD1800K1 is too thick.

We simulated ten years of normal DIY use drilling into a variety of materials. To score top marks the drill had to be in good working order at the end of our test. Models that showed signs of wear were downrated according to when the problems occurred during the testing.

Best Buys

If most of your drilling is for masonry, the Bosch PSB 14.4 VE-2, Ł75 from Robert Dyas, is our Best Buy. It's durable and easy to use, although its battery life is short. A good all-rounder is the Performance Power Pro 18v, Ł90 from B&Q. But it's worth noting that this drill is particularly heavy and is out-performed by some of the other drills in the toughest tests.

The Best Buy for a wide range of light drilling tasks is the Bosch PSR 14.4 VE-2. We found it for Ł54 in Focus Wickes. Its price tag means it replaces our previous Best Buy, the Metabo BST 12 Plus, which gets the same overall score but costs almost four times as much.

Our tests showed some models are worth avoiding. The worst performer was the Draper CD180VK, with a total test score of just five.

If you prefer a corded hammer drill, try the Metabo UHE 22, which costs around Ł210, or the Hitachi DH24PB, at around Ł257.