I have an eTrex which I just turn on and chuck in the back seat which I use as a data recorder. Battery life is 10 hrs plus, and I have put a load of waypoints in it so I can use it to navigate in an emergency. When I get home I download it to MemoryMap or Google Earth....
You have a very expensive taste in survival bags!
Just saw this
- I meant survival kit - with water, space blankets, food, medical supplies etc etc , not a sleeping bag type of thing!