Map (and compass) works all the time with no need to have batteries. Map gives far more information about general wider surroundings and possible places of interest and good views etc. GPS is significant only when one is lost or cannot see, and easily will provide the one thing you really need: to know exactly where you are. GPS has other interesting information (e.g. how far to start), but you always know these data approximately anyway.
Carry GPS and batteries for when you are in difficulty. Otherwise use 25 000 map.
Map (and compass) works all the time with no need to have batteries. Map gives far more information about general wider surroundings and possible places of interest and good views etc. GPS is significant only when one is lost or cannot see, and easily will provide the one thing you really need: to know exactly where you are. GPS has other interesting information (e.g. how far to start), but you always know these data approximately anyway.
Carry GPS and batteries for when you are in difficulty. Otherwise use 25 000 map.