I have a Samsung Galaxy Nexus LTE with the Samsung 2100 mAh extended battery. This is fine for my daily use, but when I travel by air I often run out of batteries. I have a Monoprice 2800 mAh battery backup pack which is convenient, when it works. Unfortunately sometimes it mysteriously doesn't work at all, and the flimsy connector means that keeping it connected to the phone is unreliable.
I've seen some cases for iPhones that have an external battery that would solve these problems. Unfortunately, the only product I've seen like this has poor reviews. Are there other solutions?