Fleet Management News & Business Info | Commercial Carrier Journal
Issue link: http://read.dmtmag.com/i/339485
26 COMMERCIAL CARRIER JOURNAL | JULY 2014 in focus: LED HEADLIGHTS I t's hard to miss the changes in truck lighting taking place today. Sealed-beam halogen headlamps increasingly are being replaced by LED headlights. Several OEMs, including Daimler, In- ternational and Volvo, are spec'ing LEDs on select new truck models, and it appears this trend only will grow as the benefits of LEDs become known more widely. "These are not light bulbs as we are used to thinking of them," says Russell Ong, business manager for Grote. "These are really sophisticated light engines that are, in fact, a totally new way of providing vehicle illumination." Among the many benefits LED head- lamps offer for fleets, Ong says, is the ability to customize light patterns and manage power on a vehicle in a way that never has been possible. "If you're running in oilfields or dump trucks, you need a totally different light pattern than a long-haul truck," he says. "Your drivers need excellent contrast at close range with a wide field of view to enable them to see terrain in front of them and objects off to the side. We can do that with LED headlamps." Fleets leading the way For that reason – and others – the LED lighting evolution is being led by fleets. Brad Van Riper, senior vice president and chief technology officer for Truck-Lite, says fleets have nearly 25 years of experi- ence with LEDs in signal and marker light positions on trucks and have come to appreciate the durability of those systems. "We have data that shows that fleets using conventional bulbs for signal and marker positions were logging lighting problems as one of their top three prob- lems in terms of frequency of repair," Van Riper says. After switching to LED sys- tems, lighting dropped out of the top 25 on that list. "Now they can get that same degree of reliability for their headlamps," he says. Another noticeable benefit is lumi- nance maintenance, Van Riper says. "Sealed-beam halogen bulbs suffer from that we call 'luminance depreciation,' " he says. Conventional headlamps gradually decline in brightness from 20 to 25 per- cent over their first 100 hours of opera- tion. "You don't really see it over time," he says. In contrast, fleets will see only about a 7 percent decrease in brightness from LED lamps over 20,000 hours of use. "The performance difference is striking," Van Riper says. A related feature that fleets find appeal- ing is the sophisticated driver board that controls the amount of input voltage the lamp receives to optimize light output. Halogen lamps take whatever input cur- rent is available. "Often the amount of available voltage can vary greatly," Van Riper says. "If the truck's batteries are weak, the system will automatically make recharging them a priority." Because conventional headlamps have no way of controlling the voltage they receive, a mere 10 percent drop in voltage to the lamp can result in a 30 percent decrease in lighting efficiency, he says. Get what you pay for LED headlamps currently cost more than sealed beam units, but Ong says the ex- ponential increase in unit life more than justifies the expense. "There are no moving parts and no filament to break to cause a failure," he says. "When a failure occurs, it's almost always a circuitry issue. That's why we're seeing LED headlamps last as long as 50,000 hours as long as their circuitry holds out." LED headlights becoming preferred spec for OEMs, fleets Fleets using LED headlamps will see only about a 7 percent decrease in brightness over 20,000 hours of use, Truck-Lite says. LIGHTING THE WAY BY JACK ROBERTS With LED headlights, drivers get excellent contrast at close range with a wide field of view to enable them to see terrain in front of them and objects off to the side. While LED headlamps cost more, they can last up to 50,000 hours as long as their circuitry holds out, vendors say.