It almost always happens. The power goes out or you're outside at night and need a flashlight. You go to use the flashlight and the batteries are dead, leaving you in the dark. What if you could find a flashlight that didn't rely on constantly buying expensive batteries? There are several types of reasonably priced batteryless flashlights available on the market, so you can save money and help the environment in the process. Invest in a batteryless flashlight and never be stranded again.
The most common type of batteryless flashlight is the shake flashlight. Shake flashlights are relatively new. They include a magnet that powers a light-emitting diode that can produce 5 minutes of light just by shaking it for 30 seconds. Power is stored in a capacitor, which can be recharged hundreds of thousands of times. They can illuminate a diameter of 6 feet at 35 feet of total darkness. They are very hardy, water-resistant and can withstand extremely hot and cold temperatures; some can even work underwater. They are economical, priced at $20 or less, and usually have warranties of five years or more.
Handheld squeeze flashlights emit light as you squeeze the handle. These types of flashlights have several drawbacks, as they are noisy and can tire your hand from constant squeezing. Also, they are often poorly made.
Crank flashlights have a small crank on one side and will emit light after several minutes of hand-cranking. They can produce light for about an hour. They often come as all-in-one units and include a radio, cell phone charger or other built-in electronic devices. A more recent development in batteryless flashlight technology is the solar-powered flashlight. It works by absorbing energy from the sun over several hours and using that energy to produce an hour of light.