There has been of great deal of ink spilled on the subject of prolonging your laptop's battery life, but what about caring for your battery? Over time, the capacity of any rechargeable battery diminishes, to the point
 at which it is no longer useful. However, with proper care, batteries can last a long time. Read this guide to make sure you get your money's worth out of your laptop's battery.

Most laptop batteries these days are lithium-ion batteries. Lithium-ion batteries are substantially better than either of their precursors, nickel cadmium (NiCad) and nickel metal hydride (NiMAH) batteries, in that they do not suffer from the "memory effect". This means that, contrary to popular belief, you do not need to let your battery run down all the way. In fact, it's better that you don't. Having said that though, I need to add that lithium-ion battery users should allow their batteries to fully discharge on the first two or three charging cycles. Beyond that, though, computers with lithium-ion batteries should be plugged in whenever they're not in use.

However, it is not good to leave your laptop constantly plugged in. Many people use their laptops largely as desktop replacements, using them on the desk and leaving them plugged in most of the time. These people would do well not what their laptop batteries charge constantly. Although there's no danger of "overcharging" lithium-ion batteries, leaving a laptop plugged in for months at a time will have a detrimental effect on its battery. If you use your laptop as a desktop replacement, try unplugging it when it's not in use. Take care to unplug the charger from the wall, too, as otherwise it consumes electricity. Better yet, leave the laptop plugged in all the time, but remove its battery. For long-term storage, lithium-ion batteries should be allowed to run down to little below half charge. Store them safely in a warm, dry location.

Despite your best efforts, laptop batteries will eventually die, and often before the laptop dies of natural causes. While this is not a major problem for people who use their laptops as desktop replacements, relying
 on AC Power all the time, this is a major issue for anyone who travels with their computer. If you've ever been in this situation, you know that replacement laptop batteries are expensive, often costing as much as $150. Next time you buy a computer, consider buying a second battery with it. This will also be helpful in the short term, as it will allow you to bring a second, fully charged battery with you, effectively doubling your laptop's runtime. Alternate between the two batteries, and you should be fine for the lifetime of your laptop.

If your laptop's battery has already run out, do not despair. If you ever thought that laptop batteries purchased from the manufacturer were ridiculously overpriced, you were right. In fact, the cells in your laptop's battery may only be worth about $20. If you are competent with this sort of thing, it is possible to rebuild your laptops battery