P1 Reasonable use of brightness
Like home appliances, the headlamps also have several different gears. In the case of the same battery, the battery life is reduced according to the increase in brightness. Each brand's headlamp has a battery life on the promotional map, which can use to reference when purchasing.
Why is it used as a reference? Because there is a misunderstanding here, most people will understand the battery life as the duration of the headlamp under a certain brightness. In fact, according to the international flashlight measurement standard ANSI/PLATO FL 1-2019, the endurance time refers to the time from the initial output power of the headlamp under test (the timing starts 30 seconds after the finger is turned on) to the time when the output power drops to 10% of the initial output value. For the duration (with new batteries), the headlamps cannot be extinguished or turned off halfway through. At present, the battery life of all headlamps on the market is: you turn on a particular brand of headlamps, and the brightness at the beginning is 330 lumens. When it slowly dims, the time required for this process is the battery life when it dims to 33 lumens.
At this time, some people will be puzzled. Some headlamps last for more than ten hours using the same three AAA batteries, and some only have a few hours? This involves a brand's design of the battery life curve. To improve the battery life, the headlamp brand will slowly reduce the brightness to achieve different durations of battery life within a certain period (basically in the range of tens of seconds to a few minutes) when a particular gear is turned on.
Therefore, the first suggestion on the choice of headlamps, don't be affected by the nominal battery life and to use the battery life curve as a reference standard. As shown in the figure below, this curve shows that 400 lumens, 200 lumens, and 70 lumens will not reduce the brightness, and the battery life can maintain at 4, 8, 18 hours.
Secondly, through discussions with runners, everyone likes to run to the end with one brightness, especially as the headlamp is as bright as possible. I don't recommend this because the higher the brightness, the shorter the headlamp's battery life. Secondly, studies have shown that brightness of about 100 lumens can ensure that you can see clearly under your feet when going uphill. When going downhill, the brightness of about 200 lumens can ensure that you can see the front clearly when you are running. The high brightness of the headlamps makes it easier for everyone to find road signs.
The first suggestion to improve battery life is to use brightness reasonably with the above. Due to the slow speed uphill, we can turn down the brightness of the headlamps. Generally, it can be seen clearly at around 100 lumens. The downhill speed is fast, and the brightness can adjust to about 200 lumens to improve the battery life!
P2 Choose the correct type of headlamp according to your needs
After talking about brightness, let's talk about the impact of the battery on battery life. Putting aside all human factors, under the same brightness, the higher the battery capacity, the longer the battery life. So, what are the primary batteries used in headlamps?
At present, there are roughly three types of batteries used in headlamps, 18650 batteries, 3 AAA batteries, and built-in batteries similar to mobile phones. The battery energy storage is 18650 battery> built-in battery> AAA battery for these three types of batteries. As for a reason, it is related to the battery voltage 、 battery capacity in simple terms.
The headlamp voltage of the 18650 battery and the built-in battery is both 3.7V, while the voltage of the more common AAA battery on the market is 1.5V. The battery capacity of the 18650 battery is generally 3000 mAh, the headlamp battery capacity of the built-in battery is generally about 1800 mAh (refer to NITECORE NU32), and the capacity of the AAA battery is generally 1100 mAh.
Battery energy storage = voltage * battery capacity.
18650 battery energy storage is about 3.7*3000=11.1Wh
The energy storage of the built-in battery is about 3.7*1800=6.66Wh
The energy storage of 3 AAA batteries is 1.5*1100*3=4.95Wh
It can be seen from the data comparison that in terms of battery capacity, battery energy storage is 18650 battery> built-in battery> AAA battery.
P3 The ultimate choice of headlamps
Back to the ultimate question, which headlamp is better for me to run 168, 100, 60? Before answering this question, I want you to ask yourself, how much is the ultimate goal to run? I suggest choosing the headlamp based on the target distance.
UT32 adopts the industry's first coaxial dual light source design. The coaxial design effectively reduces the weight of the lamp body while the volume remains unchanged. High-power dual light sources can switch with one hand, enriching various lighting needs for trail running. UT32 innovatively uses Polar Vision technology to simulate natural light sources, allowing users to get the lighting experience of running under natural light.
The primary light source output is as high as 1100 lumens. The intense brightness is equipped with a high-efficiency and energy-saving ultra-vision technology reflector to meet the wide-angle lighting needs of trail running at night. The secondary light source adopts high-penetrating warm light with a solid light-gathering ability and a precise long-range shooting distance of 117 meters. The warm light has an undeniable penetration advantage, and it can deal with all-around cross-country running rain, fog, snow, and other weather.
Human eyes will adapt to the dark environment. Therefore, in many cases, do not turn on the headlamps to the brightest at the beginning. Slowly adjust the gear from dark to a higher level of brightness so that the eyes will adapt more quickly. When running uphill, the brightness can lower because the running speed is slow, and when going downhill, the speed is fast, and the brightness can be increased appropriately. I also hope that everyone will enjoy the fun of trail running and finish the race safely!