Here’s how it works: You’re at home and it’s 15 degrees outside. You don’t want to get into a cold car, so you whip out your smart phone and warm your car to 68 degrees. Since the car is still plugged in, you’re not draining the battery. In summer, on a 100 degree day, you tell the car to be cool when you step in. It’s all done by way of an app provided by Airbiquity, the same company responsible for the OnStar system and Ford Sync, a service that provides hands-free calling, directions and emergency assistance.

The Airbiquity app does other things for electric vehicle owners. It removes what’s called “range anxiety,” the fear that you’ll run out of juice before you reach your destination.  The Leaf will only go about 100 miles on a single charge, so the Airbiquity system  tells you first thing in the morning how much of a charge you have.  It also sends you a text message if you haven’t plugged in your car at night, and lets you know where the charging stations are.

The Nissan Leaf in this video is about a mile from where the author of this post grew up.

The Leaf knows who’s in the car by identifying your phone. Your profile comes up and it shows buttons for the radio stations you want. A different driver steps in and their phone is discovered, along with their preferences. Make changes to your profile and your interface looks different the next time you step in.

Although 20,000 people have signed up for a Leaf, they’re rolling out slowly. You can see them now in Seattle, Portland, San Francisco, Phoenix and Nashville. They cost around $26,000 after the tax savings.

A charging station is only twice the size of a cereal box. If you plug into a 110/120 volt outlet, a charge takes about 20 hours. It takes seven hours with the $2000 charging dock recommended by Nissan and about 30 minutes for the charging stations being made available to businesses. Already, stores like Target and some shopping malls are starting to put in charging stations so that electric vehicle owners will have an incentive to shop there.

From an environmental standpoint, the existence of a lot of cars plugged into outlets in a company’s parking lot is like a mini power plant that saves power companies from having to build more facilities to handle peak demand. Most vehicles are parked an average of 95 percent of the time, so their batteries could be used to let electricity flow from the car to the power lines and back, with a value to the utilities of up to $4,000 per year per car. Researchers at the University of Delaware are trying it out now.

Experts are predicting 300,000 electric vehicles on the road within three years. More info at nissanusa.com and airbiquity.com. Airbiquity is in talks with Tesla Motors and nearly every manufacturer building or considering an electric vehicle.

February 2011 Update: Only 87 Leafs have been sold to date, though there’s a massive amount of back-orders. More here.

Wildcharge came out with just such a pad two years ago, and now Duracell, a leader in batteries, has licensed their technology for a similar device called the “myGrid,” which can charge up to four devices at once. The trick is that you need to keep a “power clip” or sleeve on your phone so that it can activate the charger. The MyGrid is $80 and comes with one power clip adapter and power clip tips compatible with various Blackberry, Nokia and Motorola RAZR phones. If you prefer the sleeve to the clip, you can buy them for the Blackberry or iPod touch for $35 each. Sounds expensive to us but a friend of ours says it takes all the hassle out of charging. The myGrid will be available in October. More info at duracell.com.

There are a score of portable power packs available today for reviving your dead or dying cell phone, iPod,  music player, game machine, Blackberry, etc. We’ve written about a couple in previous columns, but we particularly like a sleek new black one from Kensington.

It’s called simply Portable Power Pack (how straight-forward) and can be charged up either by connecting it to a USB port on any computer or using its small power adapter plugged into a wall socket. It takes about an hour to fully charge it off a USB port connection, and it will restore your mobile device to full power in a few seconds. That’s enough for about 55 hours of music play or five hours of cell phone talk.

The Portable Power Pack is smaller than a deck of playing cards and half as thick. A sequence of LED lights on one surface lets you judge how much power is left. The device comes with a USB cable and adapter plug for attachment to an iPod or smartphone. It’s $60 from Kensington.com.

The little kidney-shaped device fits easily in one hand, and a little fan spins in the wind to charge its battery. We figure there’s a definite limit on how long someone is willing to stand and hold it up in the air, hoping for a steady breeze, so the accessory pack offers an easier way.

A small case and clamp costing $10 lets you attach the HYmini to a bicycle handlebar or partially opened car window. Clipping along, the fan spins merrily and a recharge takes an hour or less. This provides enough power to run an MP3 player for two hours or a cell phone for 40 minutes. If there’s a decent breeze at your local outdoor cafe, you can sit and recharge (the HYmini, we mean} in about the same time.

The company is throwing in a solar panel for $10 on a sale right now. The car mount, bike mount and armband accessories are all back-ordered until 2008.

Portable power for cell phones, Blackberries, Apples and other assorted fruit is becoming a must-have. Fortunately, there are dozens of companies eager to provide.

·  One simple solution is a power adapter that plugs into a car’s cigarette lighter socket. We have one of these gadgets from Kensington (Kensington.com), and it costs about $10. It weighs less than an ounce. One end plugs into the lighter socket, and the other end has a standard USB port.

Now a lot of devices are able to take on power through a USB cable. You need an adapter to fit on that cable, but these are commonly available.

If you don’t want to keep tripping over a cable lying on the floor of the car, you can get retractable ones from a number of vendors. We have one from Keyspan ( Keyspan.com). Both ends retract into a little black holder about the size of a squashed gumball. These retractables cost around $5 to $10, depending on where you get them.

·  But what if you’re not in your car when you need this extra power? What if you’re up a creek without a paddle, tracking through the jungle or lost in the mountains? Fear not, there are solutions.

Solio.com makes a fashionable-looking solar charger that opens like a Japanese fan. Open it up, point it at the sun and you’re in business. Cost is $100.

For much less, we found an SC002 Sun Kit charger for $30 at SolarStyle.com, and it seems to perform essentially the same function. It looks like a small paperback book, and when you open it up — viola! as we say in fractured French — there are two solar panels, and if the sun is shining, you’re in business. Both these devices come with connectors that attach the solar cells to a wide variety of devices, mostly cell phones.

Ah, but what if the sun isn’t shining? What if you’re trapped inside a wrecked building, stuck in a tunnel, riding on a train, etc.? Well then, you should be carrying a portable power cell that you previously had the foresight to charge up while you were at home or the office.

We recently got one of these from England. It’s called PowerMonkey, from PowerMonkey.co.uk, and it looks really neat, like a miniature torpedo. It comes with more connections than a long-term politician and costs $70. Unfortunately, we couldn’t connect it to anything and couldn’t even charge it up.

A Web store called AACharger.com sells Charge2Go for $20. This is a holder that contains a rechargeable AA battery, plus connectors to fit a lot of cell phones. It’s cheap and lightweight, but limited to low power requirements.

As long as we’re willing to look at items costing as much as $70, APC’s Mobile Power Pack UPB10 (another catchy product name) looks good. It measures 2 by 8 by 10 inches, weighs 1 pound, and offers up to 55 hours of rechargeable run time for cell phones, iPods, digital cameras, portable game players, etc. We found it for $60 at Amazon and other online vendors. APC has been in the power backup business since the Earth cooled.

·  But what if it’s dark, you’re inside a building collapsed by an earthquake, and you forgot to recharge the portable backup battery for your cell phone? Jeez, Louise, you are in trouble. Still, there’s hope: You can buy a wind-up charger. These are like the wind-up wall phones you see in old movies, only palm size. You turn a crank and this generates enough current to charge a battery or condenser with roughly equal time in low-voltage electric current. In other words: two minutes of cranking, two minutes of talking. They typically come with a built-in flashlight as well as a socket for connecting the phone.

Where do you find these things? You Google them. Google has become a verb, of course. We were talking to a friend in Philadelphia a few weeks ago and asked him a technical question (he’s a physics professor), and he said, “Did you Google it?” Did we Google it? Whaddaya think, we’re some kind of low-tech ninnies? Of course we Googled it. If you go to Google.com and type in the words “wind-up chargers,” it will bring up pictures and prices of a whole lot of cranks. They generally cost around $10 to $30.

If you have stuff with weird sockets, and you don’t know where to get the right connector or whether a certain charger has that connector, visit the Web site for NewYorkCellPhone.com, which has taken the useful step of listing manufacturers’ model numbers and what goes with them. Or: Google it. Gotta go now; we have a call coming in.

There are two problems with recharging things on Earth. One is finding a place to plug in, but the bigger problem is finding a connector that fits the gadget. We recently tried out the new PowerAid Mobile from US Modular, a backup battery that comes with five adapters that fit cell phones, iPods, Treo PDAs and many other devices designed to take their charge from a computer’s USB port or a wall outlet. None of the adapters fit our Sony-Ericsson cell phone, but that wasn’t crucial since we can never remember to turn it on.

The PowerAid Mobile weighs about 10 ounces and fits in a shirt pocket. It can recharge your cell phone or PDA in an hour. It holds a charge for two to three hours of heavy use. (Five indicator lights tell you how much charge is left.) It comes with a transformer that allows recharging from a standard electrical outlet and a USB cable for charging it from a computer’s USB port. If you recharge from a computer port, it takes about six hours.

Having the PowerAid in your pocket is one solution to a dead gizmo, but what if your devices aren’t compatible with it?

Targus.com will sell you just the tip you need to plug into a portable device, but it doesn’t have tips for every phone. (Once again, it didn’t have one for our phone.) The tips run around $10 each and a charger to fit them sells for $20. But that does not include a backup battery you can carry with you, like the package from US Modular. The PowerAid Mobile lists for $50 at their own site: USModular.com, and it was the same price atTigerDirect.com.