How to Choose Emergency LED Flashlights
Hand Crank Dynamo, Solar and Power Failure Rechargeable Flashlights
Aug 12, 2009
Emergencies can be short or long in duration, can happen when at home or outdoors. Some common scenarios are:
- Random power company blackouts lasting a few hours.
- Hurricanes, earthquakes and other disasters: multi-day blackouts.
- Getting lost when hiking, camping, hunting or fishing.
- Vehicle breakdown.
Power Failure Rechargeable Flashlights
Power failure flashlights are designed for home use. They are rechargeable, and plug directly into the mains electrical socket.
When power is cut the flashlight automatically switches on, acting as emergency standby lighting. This also allows the flashlight to be easily found: no more fumbling around in the dark.
The flashlight can be unplugged and used as a conventional flashlight. Many also act as a night light when plugged in. Some are only guide lights, which are dimmer than night lights. Popular brands include Nitelite, Garrity Industries and First Alert.
Advantages
- Easy to find. Flashlight is always plugged-in and self-illuminates during power failure.
- Batteries are always charged.
- No need to remove batteries for charging.
Disadvantages
- Automatic-on means that it is possible for the flashlight to switch on when everyone is asleep or when there is nobody home, unnecessarily running down the batteries.
- Limited to home use.
- Rechargeable batteries have limited life.
Useful features
- Replaceable AA rechargeable batteries. Rechargeable batteries don't last forever. Replaceable batteries mean that the flashlight doesn't need to be junked when they fail.
- LED lights. While LEDs have replaced incandescent bulbs in normal flashlights, some power failure flashlights continue to use power-draining and unreliable incandescent bulbs.
- Non-blocking or pass-through design. Many flashlights will block the second wall socket. A pass-through flashlight has a socket in front where other appliances can be plugged in.
Solar and Dynamo Hand-Crank Emergency Flashlights
These flashlights are designed for extended use without access to any additional external supplies. However they still depend on rechargeable batteries. Rechargeable batteries can slowly lose their ability to hold electrical charge. Any claims of "never having to change batteries" are therefore inaccurate.
Solar flashlights require no effort to recharge but don't work well in storms and other limited sunlight conditions. They are more reliable as they have no moving parts.
Hand cranks can deliver 10 to 60 minutes of light for each minute of cranking. About one turn of the crank per second is a comfortable rate. Some flashlights require 2 or 3 turns per second, which is more difficult to achieve. Most hand cranks can light up the flashlight even if the rechargeable battery is dead. However the crank has to be continuously turned.
Some flashlights are all-in-one emergency devices, combined with a radio, compass, whistle or siren. Dual-power solar and hand-crank units are also available.
Advantages
- Theoretically unlimited battery endurance.
Disadvantages
- Requires sunlight (not always available) or hand cranking (requires effort).
- Rechargeable batteries have limited life, especially if overcharged or left discharged for months.
Useful features
- Replaceable AA rechargeable batteries.
- Charging indicator. Lights up when crank is turned fast enough to generate enough voltage.
- Charging socket for handphones. These work, with limitations. It can take 10 minutes of cranking to charge a phone for 1 minute of talk time.
Shaker and Squeeze Dynamo Flashlights
Instead of a hand crank, some dynamo flashlights are powered by squeezing or shaking the flashlight.
Advantages
- One-hand operation.
- Small and light.
- Shaker flashlights can be completely sealed and waterproof.
Disadvantages
- Typically harder to charge compared to a hand crank, requires more effort.
- Less powerful. No handphone charging or radio.
Portable Every-Day-Carry Flashlights
A normal battery-powered LED flashlight can make a good emergency flashlight. Small LED flashlights can fit into purses or on keychains and can be carried everywhere, everyday. As an emergency can strike at any time, having a flashlight close at all times is an advantage.
AA and AAA LED flashlights can shine for tens of hours on one set of batteries.
The Best Emergency Flashlight
Batteries, whether rechargeable or disposable, are the weak link in flashlights. They should be tested at least once a year. Having a variety of different flashlights will increase the chances of having a working flashlight when an emergency strikes. Disposable AA lithium batteries have a shelf life of 10 years.
Candles and matches should also be kept as a backup. They can be stored for years and are more reliable than batteries. Other alternatives include using a solar battery charger to charge AA NiMH batteries for a conventional flashlight.
Whatever the solution chosen, it is important to test the practicality and reliability of the solution with a realistic multi-hour dry run. A lantern-type flashlight might suit some purposes better such as reading for hours to ride out a storm. A headlamp can be more practical when both hands are needed. Test items include:
- Battery life.
- Hand crank mechanical durability.
- Flashlight brightness.
- Handphone charging capability (if available).
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