Anker Battery Holder for Bike

This is a battery holder for an Anker Astro Mini 2600. I've been using my iPhone as a cycling computer and need a place to hold a backup battery on my bike. This holds a battery underneath the handlebar stem on my bike.

Link to battery on amazon:
https://www.amazon.com/dp/B005X1Y7I2/ref=cm_sw_su_dp