Forgot to charge your main battery? Lupine Hardcase Battery 2.2Ah Bike Mount - The ideal system back-up battery.
The smaller SmartCore and Hardcase Batteries are ideally suited for mounting on the helmet or the bike. They are small and light enough to carry all night long on the helmet. Do you often switch your light between activities like walking, skiing, orienteering and biking? The clever hardcase battery can be mounted almost anywhere.