Recommending a crush-proof external battery for S4

[johnbackhouse]

I'm always using GPS and have my screen on full brightness. I was looking for a battery to keep my phone charged when I go camping. and I found this one: http://www.kickstarter.com/projects/625327275/extremely-durable-battery-pack-for-smartphones-and It looks durable (they run over it twice with a car in their video). It comes with a car adapter if they reach $100,000 (now they are at $88,000). I really want that, but they only have a week left. Anyone would like to join me? On their Kickstarter page, it says that their 15,000mAh version can charge an S4 up to 4.6 times.
Oh, here's a third-part review article of it:
Noisestash: Zendure, a tough battery that will keep your mobile devices juiced! | The Noisecast