Cold weather draining headlamp and GPS batteries?

rustleleaf

The headlamp battery dropped to nothing after just a couple hours once the air turned cold on the trail, even though I’d started with fresh cells and kept the output on low. The GPS showed the same early drain and lost its lock a few times after sitting in the pack. Not sure if body heat in a pocket would change the cells themselves or if it’s the contacts getting affected.

tentmaster

rustleleaf, body heat in a pocket helps the cells but won’t do much once contacts get condensation or corrosion on them in the cold.

FogTrek

tentmaster makes a good point on the contacts. The cells themselves lose a lot of their effective endurance once the temperature falls, even on low output, because the chemical reaction inside slows down. Keeping the whole device closer to body temperature seems to matter more than just swapping in warm spares after the fact.