Mine lasts 2-3 days using GPS sparingly. BCN allows you to turn GPS on and off separately from actually using the app. This is nice if you know how to read a map you only have to use it occasionally to verify you are where you think you are. If you want to do a route track it is also highly configurable. The other apps I believe only turn it on when the screen is on and you're looking at it, at which point the GPS is the least of your worries because the screen is the primary consumer.
Using my phone as my GPS, music player, playing 15-30 min of games every night and taking the occasional picture; as long as it's in airplane mode it sees 2-3 days on average for sure. Recently the battery has started to suck so I'm sure it's less than that now. I carry a charger to charge off 18650 batteries that power my flashlight.