Most importantly of all, it’s green: Petzl’s CORE is a rechargeable battery pack that is compatible with the brand’s entire line of TIKKA 2 or ZIPKA 2 headlamps. It uses a lithium ion polymer battery that is guaranteed for 300 recharge cycles, thus sparing the consumption of at least 900 regular AAA batteries. And it’s not only eco-friendly, but wallet friendly as well, because it pretty much pays for itself after just a handful of recharge cycles.
Although a few larger headlamps (such as my personal favorite, the Black Diamond Icon ) have utilized rechargeable battery packs for a while now, in the realm of compact headlamps – which the vast majority of road and trail runners use because of their convenient size – there was a huge void in similar green technology. Yes, some compact lamps are compatible with rechargeable AAA batteries, but from my experience those batteries don’t burn nearly as brightly or as long as alkaline batteries. The CORE doesn’t remedy that situation to perfection – there’s still a bit of a brightness dropoff, as I’ll explain shortly – but it represents a huge step in the right direction.
Since the TIKKA XP2 is my compact lamp of choice ( see my review ), that’s the one I tested the CORE pack with most frequently. Here’s how it works: instead of opening the battery case as you normally do, you separate the headlamp into two separate pieces with a twisting motion. I was a bit apprehensive in doing this the first time, because it kind of feels like you’re breaking the thing completely apart. (The dude on the demonstration video embedded below makes this looks extremely easy, but I have to say that I still feel a bit of hesitance when twisting my casing open.) The CORE pack then snaps into place between the two pieces you’ve separated, and powers the lamp just as your alkaline batteries did. Headlamps with the CORE pack still maintain the specified water resistance of the standard casing.
CORE wedged between front and back of standard casing
Placing a new middle compartment between the original housing pieces makes the overall profile of the headlamp visibly thicker, but in practice it wasn’t extremely noticeable. The only times I noticed additional bouncing was when I really hammered the pace, particularly when running downhill – but for 95% of my mileage, it’s hard to tell a difference in bulk attached to your headband. That might be thanks to the overall weight of the CORE, which at 30g is nearly identical to the three alkaline batteries (typically 10g each) that you've replaced. Even better for me from a practical standpoint is that the lamp is still small enough to tuck into the pocket of my waist pack when I’m continuing my run after sunrise.
LED indicator circled in red
The CORE pack has an LED battery indicator to tell you precisely what percentage of charge remains: either greater than 75 %, 50-75%, 25-50%, or less than 25%. It recharges via a standard USB cable into your computer or any other power source with a USB port. If your wall outlet or car charger has a USB adaptor, you can charge the CORE there as well. Recharge time is approximately three hours from a fully drained start.
Cable port underneath protective cover
As mentioned earlier, the CORE is compatible with every model of Petzl’s TIKKA 2 and ZIPKA 2 series headlamps, but since all of those lamps have different light outputs, an ideal battery pack would be able to determine how much power is needed to produce the necessary brightness level for various lamps with maximal efficiency. That’s where the “smart” element comes into play, with the help of a free software package called Petzl OS .
After downloading OS onto your computer, you open the program and plug your CORE pack into the USB port. The program then asks what lamp you’re using the CORE with – you can use multiple profiles if you have more than one lamp – and what brightness settings you’d like to program into the pack. You can customize the brightness settings to whatever levels you want (within the range of the original lamp specs, obviously), and if you’re a visual person, the OS program features graphs to help demonstrate the brightness vs battery life relationship of various settings (the video below this post has a great demonstration of this).
Unfortunately, what you can’t do is get the same lumen output or light distance with the CORE as you can with alkaline batteries. For example, a normal XP2 has a maximal output of 60 lumens on the high setting and shines a distance of 60m in spot mode, but the brightest burn you can get with the same lamp using a CORE pack is 50 lumens and 46m. In my opinion, this is the most significant drawback to the unit, because as a trail runner, brightness is king when it comes to the overall utility of any particular headlamp.
As recently as one year ago, the Tikka XP2 had a substantial brightness advantage over its main competitor, the Black Diamond Spot . Then BD went and raised their game significantly, packing 75 lumens into the updated Spot, and 100 lumens into a similarly-sized casing for a new model to be released very shortly. (And in case you’re wondering – yes, I have each of those, and I’ll be reviewing them soon.) I’m all for being eco-friendly when the performance dropoff is marginal, but stepping back from 60 to 50 lumens at the same time that I have an equal-sized lamp putting out 75 isn’t quite the tradeoff I was hoping for. I’ve found the brightness from the CORE plenty sufficient for neighborhood running, groomed trails, or fire roads – but if I’m venturing onto highly technical trails in the dark, I like a little more candle power to light my way.
Aside from the highly demanding lighting needs I just described, the Petzl CORE pack is truly a wonderful option for anyone who uses the company’s line of compact headlamps. It has outstanding versatility and customization, and from a social responsibility standpoint, it’s an absolute home run. Hopefully future models will have a bit more muscle to burn a little brighter, but in the meantime, the current version fills a much-needed void in the greening of compact headlamps.
The Petzl CORE pack retails for $40 from TravelCountry.com , where you can also buy the TIKKA XP2 headlamp for $55 .
"CORE Rechargeable Battery" by Petzl (click to play)
* Product provided by Petzl
Get updates as soon as they're posted! Click here to subscribe to Running and Rambling.
Check out the Running Life book for a collection of our most popular columns.