Cordless tools let you go wherever the job is, but they leave
you at the mercy of your rechargeable battery. If you fail to
charge your battery properly, your tools will be rendered
useless. But with a little care, you can maximize your
rechargeable battery's life. There are three types of
rechargeable batteries. Nickel-cadmium (Ni-Cd) batteries have
been around the longest and are the least expensive, but they
also have the shortest lifespan. The majority of new cordless
tools use lithium-ion (Li-ion) batteries, which are more
powerful, more compact and more durable than Ni-Cd batteries.
Nickel-metal hydride (NiMH) batteries are the least common type;
they lose their charge quickly when not in use. The lifespan of
a rechargeable battery life is measured in cycles, or the number
of times you can charge it before it loses the ability to hold
power. Lifespan varies between types and brands, but in general
lithium-ion batteries last about three to five years, or up to
three times as long as nickel-cadmium batter