In his book, "4-Wheel Freedom: The Art of Off-Road Driving", Brad DeLong said something roughly like, "When off-roading at night, auxiliary lights will be very useful, especially when there's need to use auxiliary lights to illuminate the side area where headlights don't cover. Forward lighting is also very useful since the ordinary 4X4 stock headlights are too weak for off-roading. Auxiliary lights consume a lot of electricity, if you do not pay attention to the use of battery power, it will be drained out very quickly."
Brad DeLong's words reminded three things for readers who are preparing to go off-roading at night:
1. The need to install auxiliary light that illuminates the side area where headlights do not cover.
2. The need to retrofit forward lighting or add auxiliary forward lighting.
3. Auxiliary lights consume a lot of electricity, be aware of the use of battery power. And if possible, a second battery should be added.
It's common to install auxiliary lights that are forward lighting, dual battery setup is rare to be seen, but that is not the case with the off-road community. It's a shame to see that there are not that many auxiliary lights that are specifically dedicated to the side illumination. Vehicles with auxiliary lights dedicated to the side illumination make driving easier because the conditions of both front left and right are promptly noticeable, especially before taking a turn, the function of these auxiliary lights are unreplaceable.
For off-road vehicles, several kinds of auxiliary lights can cover the side area where headlights don't:
A pair of 18W 3012 series lights in a wide flood beam mounted on both sides in the front of the car would illuminate the front left and right respectively, although their irradiation distance is limited, their scattering area is considerably large. Two 3012 auxiliary lights on the left and right combined with the stock headlights can illuminate a large area, making the illumination area of the driving direction close to 180 degrees. These kinds of auxiliary lights are extremely practical while off-roading at night, allowing drivers to clearly see the conditions of both sides of the trail in time, making it safe and convenient to choose the right off-roading route.
The most commonly seen auxiliary lights are forward lighting, including driving lights, spot lights, fog lights and even flood lights. They are usually mounted on the front and roof rack, some of them have also been mounted on the hood. And it's also very important to do the wiring correctly.
Auxiliary lights cannot be randomly mounted at will, auxiliary lights with different functions have to be mounted on different places. For example, fog lights, driving lights and flood lights have to be mounted on the front of the car while spot lights can be mounted on the front or the roof rack depending on your needs. If fog lights, driving lights or flood lights are mounted on the roof of the car, and when they are turned on there will be glare reflected by the hood or even the windshield thereby affecting the driver's view. Some fog lights scatter almost no light in the vertical direction, but even if the fog lights do not project any light onto the hood, they should not be mounted on the roof of the vehicle. In awful weather like dense fog, rain and snow, because the wavelengths of the fog lights can penetrate dense fog even though their illuminate distance is limited, any driver would want this distance to be as long as possible even if it's just one meter longer, because it may be the silver lining of a critical moment. Also, if auxiliary fog lights were mounted on the roof of the vehicle, when encounters rain or snow, it's still going to affect the driver's line of sight even though it's not as severe as other auxiliary lights. If you have to mount spot lights on the roof of the vehicle, you should mount them behind the extension line of the A-pillar or windshield, otherwise, any particle caught on the windshield glass will become very prominent, seriously affecting the driver's view.
Most off-road vehicles nowadays come with stock fog lights, but a lot of them don't qualify for off-road environments. And so, lots of people chose to have fog lights offered by professional off-road modification workshops. Therefore, fog lights are also included in the ranks of off-road vehicle auxiliary lights.
Among the off-road auxiliary lights, the most common kind are spot lights, because out in the field, they play a significant role.
When the vehicles' stock reverse lights are too dim, and if it's difficult to see the situation behind while reversing, a lot of people will add reverse lights at the rear of the vehicle, these lights tend to be compact-sized flood lights or wide fog lights.
Things to be noted when mounting auxiliary lights:
Auxiliary light mounted on the front of the vehicles should not be the front end of the vehicle, it should be mounted behind the front bar, otherwise, the auxiliary lights would be the first to take damage once rear-end collision occurred. In other words, you should let the front bar protect the auxiliary light and not the other way around. Also, the place you choose to mount auxiliary lights should not be lower than the front and rear bar, otherwise it will make the approach angle and departure angle of the vehicle smaller, which will increase the probability of a collision when the vehicle encounters an obstacle, making the auxiliary lights easier to get damaged. Auxiliary lights mounted on the roof rack will increase the height of the vehicle, when you enter a basement or cross through trees out in the wood, be aware to protect the auxiliary lights on the roof rack.
When too many auxiliary lights are installed on your vehicle, you can choose to set up a double battery system and connect all the auxiliary lights to the second battery. And so, no matter how much electrical power the auxiliary lights have consumed, it will not affect the storage capacity of the stock battery and cause ignition failure.