You should've used that money towards this external battery. Holds enough juice to charge an iPhone 6 at least 11+ times in comparison to the 1.75 times with the mini. $18.99 with code J29D3UMJ

Keep in mind that you're sacrificing portability, but if you're sporting a Camelbak then it won't really matter. Plus, if you're camping then it's also handy for those with you over the weekend that may need it. I personally have this external, but the one I link caught my eye on a deal site and thought I would share.

Here are two additional alternatives that I've used: https://www.amazon.com/gp/product/B00FDK2G2C https://www.amazon.com/gp/product/B005X1Y7I2

I have this EC tec one. I like it so much I just bought a second one. They're worth every penny.

EC Technology Portable Charger 22400mAh External Battery Power Bank, High Capacity Power Bank with 3 USB Outputs for Mobile phone ,iPhone 6/6S/5/5S/4/4S/Samsung/iPad-Black and Red

https://www.amazon.com/dp/B00FDK2G2C/ref=cm_sw_r_other_apa_q-rIxb63N4FRA

Okay, this is a Power Bank, the only difference is it used Lithium-Ion 18650's. They're a large, single cell battery with a 2,500 to 3,000mAh capacity. This has 8 of them, apparently for $33

Now, I vape. I know 18650's. They can be cheap with a wholesale licence.

https://www.amazon.com/EC-Technology-Portable-22400mAh-iPad-Black/dp/B00FDK2G2C/ref=sr_1_2?s=wireless&ie=UTF8&qid=1468729038&sr=1-2&keywords=power+bank+20000+mah&refinements=p_85%3A2470955011%2Cp_72%3A2491149011

I have 2 of these for me and my wife. Between both of us, that lasts us all week.