It never hurts to have a replacement or spare battery for those extended caving expeditions. The Petzl ACCU 2 and 4 Ultra Rechargeable batteries for Ultra Rush, Ultra Rush Belt, Ultra Vario, and Ultra Vario Belt headlamps hold enough power for 2 to 73 hours of light (depending on the headlamp and mode). When the energy gauge lets you know that you are about to be more blind than a bat hundreds of feet below the surface, you'll be grateful for the spare.
- Rechargeable battery made out lithium-ion for maximum performance in low temperatures
- ACCU 2 takes three hours to charge and ACCU 4 takes five hours for usage up to 38 hours (ACCU 2) or 73 hours (ACCU 4)
- Energy gauge on battery warns user of low battery life so you won't figure out your battery is dead halfway through your descent in the dark
- Waterproof up to 1m for 30 minutes without maintenance afterwards