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 batteries, says Elisa Bernick of home-improvement magazine The Family Handyman. Here are a few tips to extend the life of your battery.read more