The ARC Li-ion really does turn night into day at the flick of a switch. Part of the big HID (High Intensity Discharge) lighting system trend in mountain biking, the Li-ion pumps out a mega 13.5 watts of light into the dark night. Powered by a fairly light and compact 300-gram Lithium Ion battery pack, the woods at Ashton Court just became a very different place!!

Three times brighter than comparable halogen systems, the Light & Motion ARC Li-ion uses a proprietary peened aluminum reflector inside the light housing to ensure a super clean, even beam pattern with no weird edges or dark spots. The light also features multiple output levels, a low battery warning, both a helmet and bar mount, and an auto shutoff designed to prolong battery life over time.

The two separate output levels and their associate burn times are one of the ARC Li-ion’s coolest features. Double click the power button on the rear of the light and it comes on in full power mode, putting out a retina burning 675 lumens of light. In this setting you get an honest three hours of burn time. Press the button again for low power - 550 lumens of light - and it’s 3.5 to 4 hours of burn time.

The ARC Li-ion also has a built-in low battery warning LED that lets you know when you’re down to five minutes of run time. With one minute left, the light dims noticeably before shutting down automatically. According to the manufacturers, shutdown occurs to prevent what they call “battery deep discharge” and helps maintain the overall life of the battery.

The mounting system for ARC Li-ion includes a bar mount (25.8-31.8 millimeters) as well as a super adjustable helmet mount. Both mounts use a breakaway system in case you whale the light into a tree or the ground. The light released as designed on a couple of bails, yet on rough, fast descents the system stayed put.

The included Lithium Ion Turbo Charger charges the battery to 80 percent in 2.25 hours and tops it off in an additional two hours. LED indicators signal 80 percent and fully charged states, and the Turbo Charger accepts wall voltage from 90-260 volts. Want to night ride in Austria? No problem.

We have run these lights in a variety of conditions. Coming from underwater lighting specialists, the system is virtually submersible. In heavy November rain the light showed no issues with water. The whole system is competitive with other manufacturers when it comes to weight (515 grams for the whole system). Although not cheap they are well worth the price. This is a quality light!

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