Battery care and feeding

Buchmann notes that some out-of-date notions persist about how to care for your battery. "With the old nickel-cadmium batteries, the advice was to let them run down from time to time and then fully charge them," Buchmann says. "That's not the case with today's lithium ion batteries, but people still have it in their minds. Even the user manuals are often wrong."

Still, Buchmann provided a few tips to ensure both longer charges and greater overall life for your battery.

15. Recharge early and often. Try to not let the charge run down too far before recharging, Buchmann advises. "There are many more charges in your battery if you recharge from 40% (used capacity) than from 80%."

Buchmann notes one exception to the above rule: Once every few months, discharge your battery completely (i.e., use the device until it's out of juice) and then recharge it. This doesn't actually result in longer battery life, but, rather, it resets the built-in software that tells you how much charge remains so that it provides more accurate readings. "It's just some digital housekeeping," Buchmann says.

16. Keep it cool. Don't leave your mobile device in a hot place. Buchmann says that diminishes the battery's ability to hold a charge.

Throw money at the problem

If all else fails, spend money. In particular:

17. Carry a spare. If you regularly push the limits of your smartphone's battery, buy a spare and carry it with you. A quick check with Froogle found that these batteries typically cost between $10 and $30, depending on your particular phone.

18. Swap in an extended-life battery. These batteries, typically sold by cellular operators and phone vendors, are a bit larger than standard batteries and may cause your svelte smartphone to bulge a bit. But they last longer, and you don't have to worry about carrying -- and losing -- a spare.

Expect to pay between $10 and $30 for an extended-life battery, again depending on your model. The increase in talk time varies widely, but you can expect a 25% to 50% boost.

Note that the previous two tips won't work with Apple's iPhone, which doesn't feature replaceable batteries.

19. Carry a portable power supply. There is a lot of innovation going on right now in this category of products. For instance, the Medis 24-7 Power Pack ($40 for a starter kit, $23 for refills) uses fuel-cell technology to recharge your battery, while Solio offers solar-powered rechargers that range from $80 to $170. Portable power supplies using more traditional battery technology, such as Big Wave Power's $100 EnergyPORT, are also available. Fully charged portable power supplies can provide your phone anywhere from three to 30 hours of talk time, so be sure to read the fine print and get the one that's best for your needs.

20. Buy an emergency power supply. As a last resort, emergency power supplies from vendors such as Cellboost and Turbo Charge are available. These are lighter, cheaper and don't pack as much of a charge as portable power supplies -- they really are meant just to fill the gap when you run out of juice. Disposable emergency supplies like those from Cellboost cost typically less than $10, while the Turbo Charge device is a bit more expensive and can be "recharged" simply by popping in a new AA battery.

Of course, if you follow the other advice in this article, you probably won't need emergency assistance. By paying attention to the needs of your phone's battery, charges will last a lot longer.