Headlamps and batteries

article046Frequent questions about lights keep popping up on the mailing lists. I do not claim to be an expert but our training circumstances over here in Namibia prompted me to do many hours of research on the subject. So my two cents’ worth…

What do we require our lights for? For navigation and movement at night, map reading, finding tracks, walking/running/cycling over rough terrain, finding objects (black banner PC’s without lights…) etc. All rather difficult when one cannot see!

Fortunately for us, light technology has been advancing at a rapid rate and the new stuff is making things “easier” for us. However the area remains a potential minefield for the novice and gaining experience comes at a stiff price! Unfortunately one pays for quality – this is ever so true when considering which lights to use.

Three types of lights are of practical use in AR – incandescent (krypton, halogen-type bulbs), LED’s (Light Emitting Diode) and HID (High Intensity Discharge).

Incandescent: Typical examples of these lights are the Silva Orienteering lamps, Petzl Zoom or Duo headlamps, Princeton Tec Solo or Matrix (bulb module) lamps as well as the well-known Mag-Lite handheld range. Included should also be most of the bicycle lights – be that from CatEye, Sigma, NiteRider etc. These lamps use a glass bulb mounted in a reflector, produce a yellowish light, can sometimes be focussed (i.e.Petzl Zoom, Mag-Lite) and have a long “throw” (reach). They are not energy efficient and there is a direct correlation between brightness and battery life – the brighter the light, the shorter the burn time (or the bigger the required battery).

The typical bicycle lights come with rechargeable battery packs and might have up to three bulbs. This allows one to choose between say for example 6, 10 or 20W output. More high tech lights include an electronic dimmer to conserve power on good roads. Bulbs last up to 50 hours or so but can fail without warning (drop it!) so carrying spares are essential.

  • Advantages: Reach, low price.
  • Disadvantages: Power hungry, fragile bulbs.- – > Enter the LED

    LED lamps: These lamps utilize small diodes that produce a clear, smooth, high quality white light. They are very energy efficient and the bulb is almost indestructible. Rated lifetime can be 50 000 hours plus with many able to last twice that long. Typical examples are the Photon Microlights, Petzl Tikka or Princeton Tec Matrix (LED module).

    How well these lamps do also depends on the electronics inside. The PT Matrix is fully regulated and last 40 hours at a constant light output. The Tikka’s is not regulated and the light quality goes down as the battery runs down but it is significantly brighter than the Matrix for the first few hours. The main disadvantage of the LED type lights is reach – and to a lesser extend – intensity. They provide good short distance light but are practically useless to distinguish features further than 20m away.
    (This feature excludes them from being used as bike lights.)

  • Advantages: Super efficient, good quality map reading light, very tough.
  • Disadvantages: short reach, can be weakHID: These relative newcomers on the market are currently the most efficient brightness vs.. runtime vs. size lights available – period. On average these lights produce four times the light output than comparable halogen lights – and that for the same power consumption. The most practical application is bicycle lighting. These lights are however very expensive – in all categories – be that bulbs or battery packs. Bulbs last about 1000 hours and are very rugged. The size and price limit their application in handheld form. As bike light they are superior to any other type of light and allow almost daytime speeds to be attained. Manufacturers include Lumicycle, NiteRider and CatEye. The NiteRider model will produce about 40W light for four straight hours!
  • Advantages: Ultimate light output.
  • Disadvantages: Price.The ideal light: The ideal light would have the quality of LED’s – smooth, realistic colour rendition without any distortion or light/dark rings, the reach of a large Mag-Lite and the duration of a Princeton Tec Matrix. But as yet we can only dream….

    Water activity lights
    Many races also requires the use of a light that are carried or tied onto racers when paddling/swimming at night. Usually cyalume light sticks are prescribed. However, several other options exist. These include the South African manufactured “Glo-Toob”, a battery powered LED tube that is quite visible, the imported Krill electro-luminescent lamp and the tritium powered tubes from NTP – Medical & Industrials. Cyalume light sticks are expensive, have an expiry date and rapidly become unusable when the sealed package is punctured. They can also not be turned off once activated. They are not affected by water and there is no electronics to fail or batteries to go flat. The Glo-Toob and Krill can be turned on/off, last a long time (30 and 50 respectively) and are rugged and waterproof. They include electronics and batteries, either which can fail. The tritium markers from NTP do not suffer from any of these defects – no electronics or batteries. The tube is installed in a tough acrylic plastic and lasts for up to 10 years.

    Racers have commonly used five battery types: Alkaline, Lithium, Lead-Acid, NiCd and NiMH.

    Alkaline: The favorite is probably the popular Duracell. Being used in anything from headlamps to the bottom ranges of bike lights. Buy them, use them and throw them away. They suffer from the common battery problem in that when used in very cold (sub zero) conditions, they lose up to 40% of their capacity – so generally we are safe in Southern Africa! For a multi day race, the batteries can become quite expensive.

    Lithium: The ideal “cold” weather battery. Almost 40% more expensive than alkaline batteries, but they are not much affected by low temperatures. They are also about 30% lighter than alkaline batteries. That is, if you can find them!

    Lead-Acid: A low cost battery commonly found in bottom-end bicycle battery packs. They are cheap to use but suffer from the same cold weather problems as Alkalines. Furthermore, they are a bad choice when used in “high drain” applications i.e. bike lights on high beam. They are heavy and take forever to recharge.

    NiCd: Still the battery of choice in medium and high drain applications. They charge easily and some types are specifically designed to fast charge. Also must be kept well above zero degrees for best performance. They are cheaper and can handle more charge/discharge cycles than the new NiMH batteries but are heavier than NiMH. They are the best method to upgrade existing Lead-Acid bike light systems without the cost of NiMH.

    NiMH: The latest batteries being used in light systems (Yeah I know about Li-I…). About double the capacity compared to similar sized NiCd, expensive and can take fewer charge/discharge cycles. They also do not like high drain applications and should preferably only be recharged once or twice a day. Perfect though for medium discharge rates, have high capacity and low weight.

    High tech LED’s will probably replace normal flashlight bulbs. Over here we are already experimenting with a “super” LED that provides 12x the existing LED output. For you guys owning Princeton Tec Matrixes: The output on one of these LED’s equals 12 PT Matrix lights! A good quality, unbreakable light. And an even more powerful (6x more powerful) one has been developed and are going to be released in November!

    Final advice: When you go shopping for racing lights, do not skimp. Try one out at night in the bush, on a gravel path, on a boat – the nice light in the shop might not always work so well as advertised. Buy the best or use a Mini Mag-Lite until you can afford one!

    When you can see better, you can move faster. An efficient light means you have to carry fewer spare batteries – saving long-term costs and weight. Otherwise you might end up with 15 different lights in a drawer, all work, but none are used.

  • Author: Coenraad Pool | Photos by Criag Dutton, Bull of Africa 2005