I've used lots of battery powered little lights this year & left them glowing. (theinspiredroom.net)
There are lots of battery eaters inside any device, but it seems that there are also some ways of make them drain your device's battery slower. (android.gs)
Bring a camera and have lots of battery time and memory space, but be prepared because your pictures will never capture the true beauty of the trek. (incatrailreservations.com)