Crank-powered Flashlights
One way to ensure that your flashlight continues to work on
a camping or fishing trip is to bring a bag of rechargeable batteries for
it…and hope that you bought enough and that they are in a high state of charge.
This could be a great deal of hassle.
Another approach is to bring a crank-powered
flashlight. A crank-powered flashlight
has a battery, like any other flashlight, but it can be recharged by turning a
handle or crank. Crank-powered flashlights vary greatly in how fast they charge
batteries and how long the batteries last, once charged. They also vary greatly in the amount of light
they give off.
Heavier crank-powered flashlights generally have larger
batteries and, therefore, generally hold a larger charge. Be sure, however,
that the batteries are Nickel-Metal Hydride (NiMH) or Lithium and not Ni-CAD. Ni-CAD
batteries are the least reliable, the least efficient, and don’t even cost
less. Lithium batteries will generally provide the most light for the weight
and charge the quickest. Small, palm-sized crank-powered flashlights generally
don’t put out much light and also don’t stay on for very long once they are
charged.
Heavier flashlights also generally have more powerful
generators built in to create more electricity in less time. A generator is
made from magnets spinning around a coil of copper; as the two spin in
relationship to each other, electricity is generated. If the magnets are small
and the copper coil is short, the flashlight will be lighter; if the magnets
are large and the copper coil is long, the flashlight will be heavier.
Crank-powered flashlights vary in the strength of the LED
used, as well as the effectiveness of the reflector that focuses the light. A
good battery with a weak LED will provide a weak light, just as a strong LED
with a small battery will provide a short-lived light. A well-focused reflector
will provide a “halo” of light around the focused beam so that you can see
clearly at least several feet on either side of the main beam. A flashlight
with 100 or more lumens of LED light will be good for most hiking needs.
A good combination is to have a crank-powered flashlight
that can also be charged by a standard household outlet or an electrical outlet
in your vehicle. This allows the
flashlight to get a full charge before you start and will considerably increase
the length of time you will get useful light.