The 18-volt or 18v battery powers most DeWalt tools, from cordless drills to jigsaws. While all the types of 18v batteries DeWalt offers are rechargeable, there's a wide range of value, charge life and cost you need to understand when shopping for batteries. Find DeWalt batteries at your local hardware or construction supply store, or order them online. If you don't have a battery charger, you'll need one; you can find multi-type chargers that will charge any of DeWalt's 18v batteries.
Purchase 18v nickel cadmium (or NiCad) batteries if you are a casual drill user or if you need to purchase the least expensive battery type. While nickel cadmium batteries are rechargeable, Michael BlueJay's website, a well-known website reviewer, terms them "obsolete," you get very few recharges and they last 50 per cent less than nickel-metal hydride batteries.
Buy nickel-metal hydride batteries if you use the drill semi-regularly and want a good value battery. These batteries go dead if you don't use them for some time, so they make poor casual-use batteries. But they are easy to find, relatively inexpensive and offer a long life and recharge function.
Purchase lithium-ion batteries for the most value for your money. These are more expensive, but they have a long life, recharge well and don't lose a charge when not in use like the nickel-metal hydride batteries do. InfoBarrel notes that these can be recharged 2,000 times, making them a good battery value for the heavy drill user or the homeowner who plans to use the drill occasionally for many years.