Original article from Extreme Lights…
The adventure racer is a special breed of outdoor enthusiast, with exceptionally demanding requirements on their gear. The ideal headlamp should be light weight, very bright, durable and reliable, with run-times that last multiple nights. Sadly these requirements are mutually exclusive. The good news is that as technologies improve, it is possible to get a light that is better suited for the demanding adventure racer.
When an aspiring adventure racer considers a light they would prioritize their requirements as follows: first is waterproofing, ruggedness and reliability, second is runtime and then only then is the light output. This article will discuss and summarise the current state of technology.
Light Emitters
The first headlamps used incandescent (krypton, halogen-type) bulbs, which was soon replaced with the HID (High Intensity Discharge) types. They were able to produce about 2%-3.5%(1) of radiated energy, which equates to 13 – 24 lumen per watt.
In recent years the LED has come to dominate the mobile lighting market for two good reasons:
- Today’s LED can convert 22%(1) of the energy to light which is equal to over 150 lumen per watt.
- Unlike incandescent filament lamps, LEDs are practically impervious to vibration.
Battery TechnologyIn the past headlamps used to be powered with Alkaline, Lead-Acid, NiCd and NiMH. They all have various benefits, but due to the high demand for the mobile market, a new contender has emerged: the Lithium base battery. The first were not much better than Alkaline long-life, but today Lithium cells have a incredible amount power.
Battery Type | Wh/kg | Wh/liter |
Lead-acid | 41 | 100 |
Alkaline | 110 | 320 |
Lithium(2)(3) | 297 | 560 |
NiMH | 95 | 300 |
NiCad | 39 | 140 |
Lithium-ion (Low grade) | 128 | 230 |
Lithium-ion Panisonic 18650B (4) | 260 | 739 |
When it comes to energy per weight (Watt Hour / kg) there are two contenders: the Primary Lithium and the new Secondary Li-ion(Lithium-ion) batteries packs. Primary batteries cannot recharge, where secondary batteries can.
The Lithium batteries should not be confused with li-ion batteries. Lithium are not rechargeable but do come in the standard AA and AAA sizes. On the other hand, li-ion batteries are rechargeable, but do not come in the standard battery sizes. The reason for this is that li-ion’s have a cell voltage of 3.6V and if installed into devices that are designed for 1.5V will result in permanent damage.
Temperature sensitivity
Temperature sensitivity is one area that adventure racers set themselves apart, as all their gear needs to be insensitive to temperature.
LED’s ability to produce light improves as the temperatures drops below zero degrees, and therefore is an ideal choice.
Both Lithium and Lithium-ion batteries exhibit good temperature sensitivity response, although there is a common misconception that Li-ion’s have a very small temperature sensitivity range. This misconception results from Li-polymer, found in your cellphone, which cannot tolerate temperatures below 0 Deg C. Li-ion range actually extends from -20 Deg C and up to 60 deg C.
The primary Lithium’s are quite exceptional in this area, having a temperature range of -40C to +60C and only a 10% reduction in capacity at 0 deg C., compared to the Li-ion which has a range of -20 Deg C to 60 Deg and reduction in 33% in capacity at 0 Deg C. This is still significantly better than other chemistries, and it is clear why Arctic explorers would prefer the Primary Lithium over others chemistries.
Price considerationIf price was not a factor then the Primary Lithium would win, however at a price tag of over R20 per cell the running cost would amount to a very large number over a span of a year. With normal training times, a high power headlamp will easily deplete a set in 8h – 12h. Compare that to Li-ion, which can be recharged between 500-1000 times, and the few advantages that AA lithium batteries have quickly become negated.
Light design and configurationAn adventure racer needs light to read maps, find beacons and see where they are going. They also need to be able to travel fast over rough terrain by running, cycling, canoeing, abseiling etc.
Each adventure racer should find what works best for them, but the race itself and its specific demands should be taken into consideration when selecting your gear.
In our experience, a multi light approach is best. In the event that one light fails, you have a backup, as well as the two lights can complement each other. For example: a high power zoom headlamp with a forced high powered flash-light is a very good combination.
HeadlampsUndoubtedly one of the most important lights to have. It frees your hands and it is instinctive to turn your head where you are looking, therefore providing light where you need it most. With today’s technology there is no reason why this cannot be your primary light.
Weight on headThe only major draw back to a headlamp is the weight on your head. Most headlamps have the battery pack built into the light or as a battery pack on the back of the light. You need to find what you feel comfortable with. In our experience, over 300g becomes uncomfortable.
Zoom lights vs Reflector lightsIn recent years the popularity of zoom headlamps has sky-rocketed. If you choose to use your headlamp as your primary light then we would advise against such lights. Here is a in-depth explanation on how it works. In short, the benefits of a zoom type light is the uniform beam it has in flood mode, which makes it ideal for trail running and map reading. The draw back is that it tends to waste a lot of light, especially when in focus/zoomed mode. The misconception is that one can concentrate the light in a powerful beam when focused. When hunting for beacons or cycling, the lack of reach becomes a major drawback in flood mode and the focused mode will not be able to compensate.
For these reasons a secondary flash-light that has a very focused beam will compliment a zoom headlamp well.
Flash-lightsThere are a huge variety of flash-lights on the market to choose from. What we find to be important is to select a small flash-light that has a very concentrated beam, as well as a wrist strap. When searching for beacons or pointing to far off formations at night, a laser type beam is ideal. Our preferred flash-light has a very, very deep reflector which concentrates all the light into a sharp and directional beam. It also makes use of the Cree XM-L2 and the fatter higher capacity 26650 li-ion cell (Assault XM-L2). At the end you need a light that is small and robust with a focused beam that can run for long amounts of time.
Cycle lightsToday’s cycle lights are very well suited for adventure racing. The benefits of using a cycle light are: separate battery pack, larger batteries, higher outputs and more robust.
Most cycle lights are supplied with a head strap or one can easily be bought separately. This allows you to put the heavier battery pack in your backpack and reduce the weight on your head. Because they have larger battery packs it is possible to have brighter light, and longer running times. For example the Extreme 1400kcan run for 7h on high and over 42h on low mode. We find that the low mode is more than sufficient for adventure racing, it produces over 1000 lumen and weights about 150g for the light and 250g for the battery. It is so light weight, you will most likely forget you have a light on you head. The beam pattern of a cycle light tends to be mixed with a wide flood element and a hotspot, which is focused. A good quality cycle light tends to have better waterproofing than equivalent head lamps.
Water proofing and robustnessOne of the most important aspects of a light is its ability to withstand whatever nature can throw at you. There is a standard called the IP Code, Ingress Protection Rating. You can read the complete code here. But in short, the higher the number the better. For example an IP68 is a lot better against water ingress than IP23. This is one area where commercial head lights seem to fall short. An IP67 rating or higher is ideal. IP67 can be submerged to 1 meter for 30min without water ingress effecting its function. IP68 can be submerged to a depth beyond 1m, which is specified by manufacturer.
We have found that cycling lights seem to be better suited for bad weather conditions. When purchasing a headlight make sure that the IP rating is better than IP67.
Suggested lights:Based on the above information, we would recommend the following lights, in this order:
Niteye HA30 (IP68)
Hannes Zietsman