I have an old cell phone.
Doesnt have a subscription any more.
battery does hold a charge for a long time.
I use it for camping.
it is OFF all the time,
powered down to OFF.
If I am in an emergency,those phones
WILL be able to dial 911 IF you have some kind of
cell service in the area.
Light,little space,and possibly a bigtime life saver.
(just remember to power it OFF,otherwise it uses
battery power for nothing)