Cellphone batteries seem to always know when you are in the middle of an important call: that's when the dreaded "low battery" signal goes off.

Here are links to four products you can use to extend that call. Each has pros and cons, so be sure to read the detailed material before trying them out. Not all work with every cellphone model, so be sure to order the one that's right for you.

Motorola's Free Charge, $79, works with a crank system that you rotate to get a charge. Forty five seconds buys you five minutes of talk time. The charger itself can be recharged, so you can plug the phone into while you are away from electricity; when the charger loses power, you can crank it to get the extra juice.
Learn more: http://commerce.motorola.com/consumer/QWhtml/freecharge.html

iSun, $80, is a solar-powered device, and gives your phone talk time by putting it in the sun. Learm more: http://www.isunpower.com

Aladdin Power, $59.95, is a small hand-powered generator/recharger that looks like a wrist exerciser. Learn more: http://www.aladdinpower.com

Instant Power, $15, think of these as disposable batteries that you open, put on your phone and use, until they run out of power. Learn more: http://www.instant-power.com/

Write to techguru@sree.net and let me know your thoughts.

To join the LOW-volume "Sree Tips" e-mail mailing list, send your name and e-mail address to sreetips-subscribe@yahoogroups.com. No more than once a month, you will receive an e-mail message with tips and tricks about new, useful and fun Web sites.