A flashlight or torch is a hand-held portable electric spotlight. It is known as a flashlight mainly in the United States and as a torch in most Commonwealth countries. A typical flashlight consists of a small electric lightbulb with associated parabolic reflector, powered by electric batteries, and with an electric power switch. The components are mounted in a housing that contains the necessary electric circuit and provides ease of handling, a means of access to the batteries for replacement, and a clear covering over the lightbulb for its protection. Although a relatively simple device, its invention did not occur until the late 19th century because it depended upon the earlier invention of the electric battery and electric light. The batteries in the first ones were of such short useful life that the common method of operating them was to flash them just long enough to discern the environs, and only as needed; hence the term "flash-light".

Recently, flashlights which use light-emitting diodes (LEDs) instead of conventional lightbulbs have become available. LEDs are far more efficient, and use less power, than normal lightbulbs, and so torches which use them have longer battery lifetimes. LEDs also survive sharp blows that often burn out conventional lightbulb models. Another innovation in flashlight design is the headlamp, a flashlight worn on the head for hands-free operation. Powerful headlamps mounted on helmets have been used in mining for decades, but general-purpose ones with fabric straps are now also available.

Most flashlights are cylindrical in design, with the lamp assembly attached to one end. However, early designs came in a variety of shapes. Many resembled lanterns of the day, consisting largely of a box with a handle and the lamp attached to the front. Some others were made to have a similar appearance to candles. It is possible that future developments of battery and LED technology will bring interesting new designs. For instance, one very small light that exists now in 2004 consists of a few LEDs with a switch, designed to be an endcap for a 9-volt battery.

Small LED torchHigh-quality flashlights go for as much as several hundreds of dollars. Such flashlights are very advanced, using special batteries, have adjustable brightness levels, dive-depth waterproof ratings, interchangeable optics, and are very bright.

Most common Torches and Flashlights run from standard size cells such as AAA, AA, C and D. Depending on how you use the torch will have an effect on which type of chemistry cell is best for you to use in the torch.

If you have the torch as a standby for emergencies then using standard Alkaline cells would be best; they have a relatively low self discahrge rate and a shelf life of up to 5 years if stored correctly meaning that you can rely on your torch to function when you neede it. Check out our Varta Alkaline section for high quality Alkaline cells here.

If you are a frequent user then rechargeable cells will be be more suitable as they can be recharged in between use meaning you can maintain a high level of usage for longer, and because use is frequent, therelatively high level of self discharge is not an issue and advantage can be taken of the high capacity of these cells. Check out our Ansmann NiMH cells section for details on high capacity NiMH cells here.