“Whoa, that’s bright!” a fellow JTree Tweetup goer said.

“And that’s only at 90%!”

How many times have you put on your headlamp, switched it to it’s brightest setting and thought to yourself, “It’s not as bright as I remember”? I don’t know about you, but I’ve thought that a lot. It turns out there’s a reason for this and it’s not just because you don’t have fresh batteries.

Most headlamps have a decreasing brightness performance, which lengthens the time you can have useable light. This is quite a reasonable trade off for a headlamp that you mainly use for the unexpected in-the-dark descent or hike out. What this means though is that the unregulated mode of a headlamp will only give you its best and brightest for a relatively short amount of time compared to the life of the battery.

Enter the Petzl CORE battery.  It’s a rechargeable battery for Petzl’s Tikka 2 and Zipka 2 lines of lamps but also provides, via the OS by Petzl software,  a way to customize your lamp’s output.

I was given a Petzl Tikka Plus 2 and a CORE battery to review from the good folks at Pembaserves and proceeded to try it out at home and then while on a 6 day trip in Joshua Tree National Park for the 2nd Annual Jtree Tweetup.

First off, I downloaded and installed the OS software. The interface was sparce with a slide show showing you how to plug in your battery and then how to configure different profiles for your headlamp(s). It was quite easy and straightforward.

Next I plugged in the CORE battery into my USB port and proceeded to choose which lamp I was using the battery with and what name I wanted to call it. I appreciated the visual graph that showed me how bright versus how long I could make the headlamp last and decided to go for a Regulated profile that would give me 90% of the light’s power for a solid 5 hours and 50 minutes. I had night climbing in mind. I then only slightly changed the Economical mode setting, making it last a total of 47 hours and  30 minutes as 10.5%. This was my “emergency mode” in my way of thinking.

Lastly, I saved the profile I had just made (with its 2 settings) so that I could use it again in the future.

Then I decided to install the battery (you can make profile changes with the battery inside the headlamp as well but I had been too eager to get it going). Looking at the instruction pamphlet that came with the battery I realized that it wasn’t just as simple as popping the battery in where the regular batteries usually go. Instead the CORE was to sit like the meat in a sandwich between the front and back sides of the headlamp. I needed to take the headlamp apart with a small twist motion. I’ll have to admit I was a little scared to do that. The folks at Pembaserves had rushed to get me the lamp and battery in time for my trip but if I broke it, there wouldn’t be enough time to replace it.

Eventually, with some reassurance via direct messages on Twitter, I did pry the back off just like the picture showed and it worked great. The final result was the CORE sitting nestled smoothly between the pieces of the Tikka Plus 2. The headlamp looked pretty much as it had before, albeit as a fatter version of itself. Petzl has since added a video demonstrating how to do this on their website.

Who's got the bright light?Use in the Field

The exchange at the beginning of this review happened during one of the cold (but beautiful) nights out at Joshua Tree National Park. While you can test to see how bright “90%” looks while the light is still plugged into your computer (very handy) it looks ever so much brighter when you don’t have a room light on.

I used my CORE powered light exclusively during my trip and did a night ascent of the Manure Pile rock formation in

Lighting up those below
Lighting up those below

Ryan Campground. It turned out to be technically much easier than it looked from the bottom, however perhaps one reason it felt easier was because I had great illumination! I was even able to light up folks back at the campfire with my light.

One thing I found really nice about having the CORE was knowing that I still had the Economical mode to fall back on if I felt my battery was going low. And, in a real pinch I could charge my battery by plugging it into any USB port (I had my laptop with me) and as a very last resort I could still remove the CORE and put in regular batteries. Needless to say, I didn’t need to do any of those options, my light lasted the whole trip.


The CORE is quite a useful addition to a Tikka 2 or Zipka 2 light. I like that it effectively replaces 900 disposable batteries and is easy to charge. I even tested it with the USB port for my SOLIO solar charger and it worked fine. For the ultra light weight enthusiasts, the CORE weighs 30 grams, I weighed 3 AAA Duracell batteries and got 1.1 ounces via my postage scale, which is roughly equal to 31 grams. So you may or may not able to go lighter depending on which batteries you are comparing with the CORE. It definitely does add a little bit of bulk though.

However I think the selling point of the CORE is the ability to create and save different profiles for your light. I’ve definitely been in situations where I’d gladly have traded brightness for length of life. And I’ve also wished for a dimmer light around a campfire, or for reading where the thing I need to illuminate is just my book a few inches away from me and not the entire tent.

CORE specs:

Lithium Ion Polymer 900 mAh rechargeable battery
Sold with 30 cm USB «micro B» type cable
Compatible with TIKKINA2, TIKKA2, ZIPKA2, TIKKA PLUS2, ZIPKA PLUS2 and TIKKA XP2 headlamps

Recharge time: 3 hours
Number of charging cycles: approximately 300
Weight: 30 g
Guarantee: 3 years or 300 charging cycles

Peztl CORE batteries are available separately or as part of a Tikka 2 or Zipka 2 package. See more at Petzl.com.

Available online at REI.com.
Petzl Core Rechargeable Battery