Mention the words "battery life." The first gadget that comes to mind is probably the energy-consuming laptop computer — particularly if you're on the go a lot.

If not, it should be. There never seems to be enough juice to run your portable PC, as I griped about in a previous article. Ah, but if laptop PCs were the extent of your battery blues, you might not feel so, well, powerless.

But power problems plague other mobile devices. For example, a 2003 In-Stat/MDR survey found that long battery life ranked as the most important feature to business users when selecting a wireless handset. Users of personal digital assistants (PDAs) are just as concerned about a possible energy crisis. I know because I am one and I never seem to stop worrying about running dry.

So, what about mobile gadgets? How do you make sure your batteries last as long as possible? Here are four tips.

1. Follow instructions and use them right — right from the start. "All batteries should be properly conditioned prior to first use," says Larry O'Connor, chief executive of Other World Computing, a Woodstock, Ill., developer of battery solutions and computer enhancement products. "You must properly prepare the battery by following the first charge and use instructions." And what if you don't? O'Connor warns that failure to follow can shorten the life or runtime of your battery. "Follow the instructions to the letter and that battery will give you a lot more," he says.
2. Don't overcharge them. When it comes to batteries for small devices such as PDAs, cell phones or Tablet PCs, the single biggest mistake users make is leaving them plugged in to the charger for lengthy periods after they've been fully recharged. "Leaving the batteries, at least those types associated with these devices, on charge for endless periods will reduce the overall life of the battery," warns Paul Klatt, a quality assurance engineer for Batteries Plus, a Hartland, Wis., commercial-battery distributor. He says battery chargers normally taper down when the battery is fully charged. "However, enduring weeks of even a 'trickle charge' creates heat buildup and will eventually cause premature battery failure," Klatt says. How do you avoid overcharging? Remove the charger right after the battery is fully charged.
3. Use them at regular intervals. This is a problem that affects spare batteries, but it can also be a factor on a backup unit, such as a second cell phone. O'Connor says batteries have to be used in order to get the most out of them. "If you have spares, cycle them at least once every six months — or even better, every three months," he says. "This will go a long way in keeping your batteries maintained to properly perform."
4. Stay away from cheap-o replacements. "Quality is very important when it comes to replacement batteries," says Stefan Betesh, vice president of product development for Sakar International, an Edison, N.J., consumer electronic products manufacturer. Many lesser-known but cheaper brands cut corners when they make their batteries. That can affect the overall life expectancy and performance of the battery. Worse, the batteries may be defective because "most low-end batteries are refurbished or just not working with quality control," he says. His recommendation? Go with a recognized brand and buy from a reputable source.

But let's be honest: Keeping your batteries at peak performance is a lot like taking care of an infant. Lots of "dos" and "don'ts" to remember — change this, stay away from that, follow the directions, etc.

Does anyone expect you to do all of this?

Well, not really.

I leave my cell phone charger plugged in overnight from time to time (OK, more than that) and I've never cycled my batteries. Is there a solution for those of us who really couldn't be bothered?

I spoke with Bill Acker, president and CEO of MTI Micro Fuel Cells, an Albany, N.Y., battery manufacturer. He tells me that fuel cells will soon become alternatives to today's high-maintenance lithium-ion batteries. The new technology can hold up to 10 times more of a charge than conventional batteries. "For the first time," he says, "wireless and other electronic hand held devices will be truly wireless."

But fuel cell technology and other innovations like it are still a few years away from being widely available. Until then, these four tips can help you stretch your power supply to the limit.