Originally Posted by
Jordy
That's exactly what you need, plenty of charge, portable and doesn't cost much.
However you could just take the common sense approach (dont mean to sound harsh), if you're camping for 3 days why not just keep your phone turned off for the duration. Camping's a very social and active thing you don't need to be playing on apps, texting/ringing people etc other than every few hours or so. I generally stick to that when camping and if worst comes to the worst I have a phone charger which works from AA Batteries, which is sufficient to make a few phone calls :)
If you're taking a car with you though, get some in-car chargers, much better :)