Too little power won't get the job done, too much is a waste of money.
So how many volts do you need? To find out, just answer one question (truthfully): How handy am I?
The Golden Rule
Stick with one manufacturer, and you can use the same battery in all your tools-as long as they have the same voltage. So don't go for a 9.6-volt drill if you think you'll want an 18-volt reciprocating saw later. The descriptions below will help you determine how handy you really are around the house-and, thus, your future cordless tool needs.
The Unhandy Handyman