Petzl CORE 2 Replacement Battery Pack for Petzl Headlamps with the Hybrid Concept Design USB-C Rechargeable Lithium-Ion Battery Pack for Petzl Headlamps The Petzl CORE 2 is a USB-C rechargeable li-ion battery pack for Petzl headlamps with the dual-fuel Hybrid Concept Design. Compatible headlamps - like ARIA and PIXA headlamps - are made to run on AAA batteries or this battery pack, giving you an easily rechargeable power option. The compact, 25g CORE 2 battery pack features both the integrated USB-C port and a color-changing indicator light to simplify the charging process. Able to fully charge in 3.5 hours or less, you can power up your main or backup CORE 2 battery quickly, whether preparing to use your light or while you're on the go. Thanks to its rechargeable lithium chemistry, it also has a total lifespan equivalent to 900 AAA batteries and offers strong performance in a broad temperature range.