To find the correct replacement battery for a cordless drill, go to the category Cordless Tool Battery Packs on the Amazon website and enter the model number for your drill in the search box. The tool's model number is typically located on a plate affixed to the product or listed in the owner's manual. Alternatively, go to the website ZBattery.com and click on Power Tool under the Battery menu to display links for major power tool manufacturers and their models.
Power tool batteries come in a variety of voltages and types such as nickel-cadmium, nickel-metal hydride, lithium ion and alkaline. Some power tools that originally used nickel-cadmium batteries can also use nickel-metal hydride batteries. Ensure your charger is compatible with both types of batteries, or the charger may damage the nickel-metal hydride battery, shorten its life and void the warranty.
Certain manufacturers, such as Dewalt, have battery packs that power not only a cordless drill, but a whole line of power tools such as a circular saw, reciprocating saw, floodlight and impact driver. This type of interchangeably helps owners reduce the number of battery packs and chargers they need to purchase and store.
Consider buying a two-pack of batteries, if available. In this way one battery pack can be charging while the other is being used, reducing downtime.