The first rule you need to be familiar with when choosing a cordless drill is this simple fact-the battery you choose to power this tool will ultimately determine the strength and torque you will get. Obviously, the higher the voltage of the battery, the more power you can expect to get from your cordless drill. While this seems to be very exciting option, there are tradeoffs to be made with a higher voltage cordless tool. There is the burden of additional cost and additional weight if you are going for a higher voltage solution for your drilling needs.
The battery chemistry has 3 types: NiCad, NiMH, and Lithium-ion. NiCad, or NiCd, battery is used in older cordless drill tools. They are the least expensive, so almost all inexpensive cordless tools use this type of battery. There is one problem with this battery. It's toxic to the environment. So when it's time to dispose the dead NiCd battery it's a problem.
Most of the laptops now a day are equipped with lithium battery stocks-ion batteries. Though there are Nickel-cadmium, Nickel metal hydride, etc, after the invention of Lithium-ion battery, because of its efficiency most of the laptop manufacturers are selling it along with their respective laptops.
Okay, so we know we'd be sunk without our laptops and cell phones. But what about the car? Cars have batteries too. Perhaps you ride a Harley Davidson - not without a motorcycle battery! It's interesting to think where we'd be if the afore-mentioned "zapping episode" took place. We know that our forefathers coped without batteries but could we?
Avoid buying spares: Unlike wine and cheese, Li batteries do not improve with age. Avoid the temptation to buy spares, unless you use them frequently. Check the manufacture date, and never buy an old Lithium battery stocks, even if on sale.
Lithium mines Ontario-Ion batteries are revolutionary in fact, not just simply better than Ni-Cd. They don't have memory effect, which means you can easily use them a little and then partially recharge them just to discharge them to a certain percentage of their capacity other than zero. They like partial charges and discharges better than full ones, but memory effect is not something you should be aware of.
Now, you may be asking yourself why your iPod does not use conventional batteries. Here is the answer: find any size battery in your home and try to place it in your iPod. You will soon figure out why lithium ion is the weapon of choice for iPod mini batteries. They are smaller, longer lasting, and have the juice to power today's high-performance devices.
Another one of the best drills out there is the Panasonic EY7540LN2L model. It makes fastening jobs a cinch. It is lightweight, and ergonomic. It is extremely easy on the wrist and hands, so it is comfortable to use. It has long lasting lithium batteries for longer jobs. It is an impact driver, and is definitely versatile. It costs more than the other two drills, but it is still one of the best. Overall, any of the drills mentioned above would be a great cordless drill to own.