How to buy flashlights
By Tim Dees
Time was when the flashlights carried by policemen were no different than what you might find in the junk drawer in any kitchen. Now, they're highly engineered, critical, life-saving tools, and a serious investment. Here's some things to think about when deciding on a flashlight:
Through most of the 1980s, police flashlights were heavy aluminum tubes at least a foot long and two inches thick. They could double as clubs, and were sometimes used that way—often leading to a lawsuit. Now, flashlights are more commonly four to eight inches long and broomstick-thick. Department policy often dictates which will be used. Some lights have a crenulated rim around the lens, intended as a striking surface.
Before you take one of these into the field, check with your department on how much trouble you might be in if you use that end to hit someone.
Standard flashlights use an incandescent bulb that produces a yellowish light. The next generation of rechargeable lights use halogen bulbs that produce a much brighter bluish-white light, but at a cost of higher power drain and a lot of waste heat (halogen lights that came on while in an officer's belt carrier melted some car seat covers). Most new lights use light-emitting diodes (LEDs) that produce white light and almost no heat, making them considerably more efficient. Higher light output is usually achieved by adding LEDs that are focused to produce a single tight beam of light.
LEDs have another advantage over bulbs in that they go from zero to peak output almost instantly. This allows them to "strobe" or flash quickly if the light has the necessary circuitry. Hitting a suspect's eyes with a bright strobing light, especially in low-light conditions, is disorienting enough to allow you to overcome an assault and restrain him.
Because they are used so much, rechargeable batteries are almost always more economical than throw-aways. An exception is lithium batteries, which aren't rechargeable, but have a shelf life of up to ten years. These are best for backup lights and those kept for emergency use. Nickel cadmium (NiCd or Ni-Cad) batteries develop a "memory," reducing their capacity if they are repeatedly charged before being fully discharged.
They also don't work well when cold. Nickel-Metal Hydride (NiMH) and Lithium Ion batteries are a more reliable choice. These are increasingly common in new flashlight models. A light that takes rechargeable batteries gives you backup capacity if the rechargeables run out of juice at a bad time.
In 2009, 5.11 Tactical marketed a flashlight that uses no batteries at all. The large form factor light uses an ultracapacitor that powers the light for 20-60 minutes (depending on setting), fully recharges in 90 seconds, and is rated to survive 50,000 charge-discharge cycles. The shell of the "Light for Life UC3.400" is made of plastic. With their recent release, they are just now being tested in the field.
Tim Dees is a retired police officer and the former editor of two major law enforcement websites who writes and consults on technology applications in criminal justice. He can be reached at email@example.com.