Review: Petzl IKO Core Headlamp

Ultralight Rechargeable Headlamp
Petzl IKO Core
$100, 2.8 oz./79.4g

As we skied back to our backcountry yurt through falling snow on a dark night at the end of a full day of touring in Idaho’s Boise Mountains, my IKO Core brightly illuminated our route through meadows and conifer and aspen forest. But brightness and low weight are just two of the measurable ways in which few ultralight headlamps match Petzl’s rechargeable IKO Core, which has unique design features that would appeal to backpackers, dayhikers, climbers, trail runners, and backcountry skiers.

At the highest of its three power levels, 500 lumens, the IKO Core is exceptionally bright—especially for a headlamp weighing under three ounces, the best of which top 300 lumens and rarely exceed 400. In campsites beside wilderness lakes on rainy, dark nights during an August backpacking trip in the Wind River Range, this headlamp lit up the open forest like a klieg light, with a broad, even beam that illuminated objects clearly for at least 100 meters (as Petzl claims for the IKO Core’s range at max brightness). I also used the IKO Core on other trips, including a six-day hike in the Grand Canyon.

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The Petzl IKO Core rechargeable headlamp.
The Petzl IKO Core rechargeable headlamp.

That degree of brightness comes in handy when trying to identify anything at a distance in the dark, like a trail marking or your off-trail route; a campsite, shelter or yurt; food hanging from a tree branch, stored in a bear canister on the ground, or cached; or a person in need of help.

At 100 lumens, the headlamp’s middle power level projects a beam 45 meters, according to Petzl; I found it certainly bright enough to follow a trail in the dark. The max and middle levels simultaneously project both a spot beam and proximity light—more useful than separating those two lighting modes, as many headlamps do. The low setting (six lumens) throws enough light for inside the tent or close-at-hand tasks in camp but seems a bit dim to me for reading, though that may not bother everyone. The only conspicuously missing modes are red and flashing.

The headlamp housing tilts through a wide range up and down. Turn the headlamp on and insert only the lamp housing inside its white stuff sack and it doubles as a lantern.

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The Petzl IKO Core rechargeable headlamp battery pack.
The Petzl IKO Core rechargeable headlamp battery pack.

While a headlamp’s brightness diminishes steadily as standard batteries drain, the Core battery maintains constant brightness over the duration of a charge before power drops off abruptly; you’ll appreciate that on a long slog after dark. It recharges in three hours via a USB port and has a burn time (how long a charge lasts) of nine hours at 100 lumens.

The IKO Core’s hybrid design enables substituting standard AAA batteries after the Core battery has lost its charge. Operating on AAA batteries, the low power performance remains the same but max power drops to 350 lumens—still brighter than max power on many ultralight headlamps and plenty bright enough for most backcountry situations—with a range of 80 meters and a burn time of two hours. (Petzl cautions against mixing battery brands or new and used batteries.)

The battery pack—easily opened to recharge the battery—has a curved, rubberized cover that’s unobtrusive against the back of your head and is only a half-inch thick, so you can lie back on it without feeling like your head is resting on a block of wood.

Operation is idiot-proof: The single power button on the housing clicks through the three brightness levels; and depressing and holding that button switches the IKO Core into lockout mode, to prevent it accidentally turning on and depleting the charge while inside your pack.

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The Petzl IKO Core rechargeable headlamp in its stuff sack.
The Petzl IKO Core rechargeable headlamp in its stuff sack.

The thin, bendable, adjustable, semi-rigid headband provides a comfortable and very secure fit with minimal area of contact against your head; it also doesn’t absorb water or sweat and fits over climbing helmets. Plus, having the battery pack in the rear keeps the lamp housing very light in front, meaning no bouncing when running, hiking fast, skiing, or scrambling in the mountains. The headband must be bent and folded to stuff into its small, super light storage sack—a task that might annoy some users but I found simple and quick. Plus, the stuff sack keeps the entire unit more compact for storage in a backpack lid pocket.

The IKO Core’s IPX-4 rating means the headlamp is resistant to splashed water from any direction but not waterproof and would very likely be damaged if immersed. That’s not as high a rating as other ultralight headlamps, some of which are as high as IPX-7, protecting them from immersion up to one meter for 30 minutes.

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The Verdict

For its low weight, exceptional brightness, useful range of power levels, comfort, ease of use, and packability, the Petzl IKO Core rechargeable headlamp will appeal to many recreational users—backpackers, dayhikers, climbers, trail runners, and backcountry skiers—and perhaps especially to professionals like guides and search-and-rescue teams.


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NOTE: I tested gear for Backpacker magazine for 20 years. At The Big Outside, I review only what I consider the best outdoor gear and apparel. See The Big Outside’s Gear Reviews page for categorized menus of all my reviews and expert buying tips.

—Michael Lanza

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