Most will probably agree that, in the scheme of important cell phone features, battery life should rank somewhere near the top. After all, few other features seem to matter when a phone's gone dead in the middle of an important call, before the perfect photo opportunity, or when you've just realized you don't know your way home.

Today's cell phones almost exclusively use Lithium-Ion (or Li-Ion) batteries. Not all Li-Ion batteries are the same, however. Differences in materials and construction have a significant effect on power capacity and efficiency, and a better battery can translate to a surprisingly significant increase in the life of your device.

In addition to offering spare and replacement batteries for those that have been damaged or have gradually lost capacity, many cell phone manufacturers also produce extended-life versions of the batteries that come stock with their phones. For those with phones that don't feature a removable battery (Apple's iPhone, for example), a number of 'smart cases' with built-in battery technology have additionally been developed to dramatically increase life and longevity.

Most will probably agree that, in the scheme of important cell phone features, battery life should rank somewhere near the top. After all, few other features seem to matter when a phone's gone dead in the middle of an important call, before the perfect photo opportunity, or when you've just realized you don't know your way home. In this article, we'll discuss the basic variations among cell phone batteries, the range of products designed to maximize the life of your phone, and the proper care techniques that'll keep them going strong:

What kind of battery does my cell-phone use?

Today's cell phones almost exclusively use Lithium-Ion (or Li-Ion) batteries, which are, generally speaking, a vast improvement over the older, nickel-based varieties. Li-Ions have a high energy density, lose energy very slowly in periods of disuse, and don't suffer from what's often termed the "memory effect"--a phenomenon where, in the process of being partially recharged, nickel-based batteries will 'remember' an increasingly lower charge capacity.

Not all Li-Ion batteries are the same, however. Differences in materials and construction have a significant effect on power capacity and efficiency, and a better battery can translate to a surprisingly significant increase in the life of your device. Even the best Li-Ions, however, do lose a very slight amount of energy (30-60 seconds worth) with each charge.

How can I extend the life of my phone?

In addition to offering replacement batteries for those that have been damaged or have gradually lost capacity, many cell phone manufacturers also produce extended-life versions of the batteries that come stock with their phones. Blackberry, aware of the extent to which its customers rely on their products for work and personal use alike, manufactures a number of replacement batteries that effectively double the life of their smartphones. That extra capacity often translates to several hours of additional talk or internet use, and days worth of extra standby life.

Of course, if your phone's manufacturer doesn't offer an extended life battery, you can always simply purchase a duplicate of the original. That way, you can charge two or more before a trip or a busy day, and if the first runs out, you can easily swap it out with a second (or third, or fourth).

For those with phones that don't feature a removable battery (the iPhone is a popular example), a number of creative solutions have been developed to maximize your phone's life without removing the stock battery. SaFPWR and XPAL have each developed cases with built-in batteries, which both extend life and combat any gradual loss of charge capacity through intelligent energy management technology (EMT).

Caring for you cell phone's battery:

Of course, no matter how many spare batteries or battery accessories you own, it's always a good idea to follow the proper care techniques. Follow these simple rules to avoid any undue loss in capacity or longevity:

• -Be sure to initialize new batteries. For Li-Ions, this means allowing the battery to charge for a full 5 or 6 hours; for nickel-based batteries, the first charge should run about 16 hours, and should be followed by at least two full discharge cycles.
• -If you're phone has an Li-Ion battery (odds are it does, if it's at all new), be sure to avoid fully discharging it; every time you do so, you'll shorten its life. Ideally, aim to charge your battery when one 'bar' is remaining.
• -As a general rule, keep your batteries away from heat--high temperatures can cause significant, accelerated degradation of battery life. If you expect any of your batteries to go through a particularly long period of disuse, you may even want consider storing them in an airtight container in the refrigerator--doing so will ensure no capacity is lost due to heat.